D32.01 - Physical-Chemical Properties

SIGNIFICANCE AND USE
5.1 This test method can be used to determine the acidity of catalysts and catalyst carriers by ammonia chemisorption for materials specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of acidity of catalysts and catalyst carriers by ammonia chemisorption. A volumetric measuring system is used to obtain the amount of chemisorbed ammonia.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This test method has been found useful for the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 m2/g to 10 m2/g for materials specification, manufacturing control, and research and development in the evaluation of catalysts. The determination of surface area of catalysts and catalyst carriers above 10 m2/g is addressed in Test Method D3663 – Surface Area of Catalyst and Catalyst Carriers – and is appropriate for most samples with specific surface areas above 1 m2/g.
SCOPE
1.1 This test method covers the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 m2/g to 10 m2/g. A volumetric measuring system is used to obtain at least three data points which fall within the linear BET region.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This guide is intended to determine meso- and macropore volume which affects heavy oil cracking performance of a catalyst. The information is useful for materials specification, manufacturing control, and research and development in the evaluation of catalytic materials.  
5.2 It has been reported in literature the existence of a correlation between the pore volume obtained from this guide and that from Test Method D4284.3
SCOPE
1.1 This guide measures pore volume of powdered catalysts and catalyst carriers by titration with water. The water does not react with material. The range of pore volume is 0.25 mL/g to 0.46 mL/g.  
1.2 This guide is suitable for fine catalysts such as fluid catalytic cracking (FCC) catalysts (fresh or equilibrium), catalyst additives and spray dried catalyst carriers or finished catalysts, or a combination thereof, and is typically applicable to powders with the majority of particles (above 90 %) in the distribution range between 20 and 150 µm equivalent spherical diameter (determined by Test Method D4464) and with an average particle size between 60 and 100 µm.
Note 1: This technique is capable of measuring particles below and above this range (for example, from 1 to 300 µm) but no precision data is available.  
1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
4.1 This test method is for estimating the relative amount of gamma alumina in calcined catalyst or catalyst carrier samples, assuming that the X-ray powder diffraction peak occurring at about 67 °2θ is attributable to gamma alumina. Gamma alumina is defined as a transition alumina formed after heating in the range from 500 to 550 °C, and may include forms described in the literature as eta, chi, and gamma aluminas. Delta alumina has a diffraction peak in the same region, but is formed above 850 °C, a temperature to which most catalysts of this type are not heated. There are other possible components which may cause some interference, such as alpha-quartz and zeolite Y, as well as aluminum-containing spinels formed at elevated temperatures. If the presence of interfering material is suspected, the diffraction pattern should be examined in greater detail. More significant interference may be caused by the presence of large amounts of heavy metals or rare earths, which exhibit strong X-ray absorption and scattering. Comparisons between similar materials, therefore, may be more appropriate than those between widely varying materials.
SCOPE
1.1 This test method covers the determination of gamma alumina and related transition aluminas in catalysts and catalyst carriers containing silica and alumina by X-ray powder diffraction, using the diffracted intensity of the peak occurring at about 67 °2θ when copper Kα radiation is employed.  
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
4.1 This test method sets forth a procedure by which duplicate catalyst samples can be compared either on an interlaboratory or intralaboratory basis. It is anticipated that catalyst producers and users will find this test method of value.  
4.2 Discrimination of the samples for which this procedure is recommended must be exercised when considering carrier (support) materials that sorb appreciable quantities of hydrogen or could cause an alteration of the state of the catalyst during pretreatment, or both, (that is, sintering or metal occlusion). These materials must be identified by the user and experimented with to determine the most significant conditions of measurement.  
4.3 This test method provides a measure of the total hydrogen uptake (volume of hydrogen at STP, cm3/g of catalyst) without specifying the nature of the hydrogen-platinum interaction. Persons interested in using hydrogen uptake data to calculate percent platinum dispersion in a specific catalyst should be aware of carrier (support) interactions, spillover effects, and other phenomena related to the hydrogen uptake capabilities of the catalyst in question.
SCOPE
1.1 This test method covers the determination of the chemisorption of hydrogen at 298 K (25 °C) on supported platinum catalysts that have been reduced in flowing hydrogen at 723 K (450 °C). It incorporates a static volumetric vacuum technique at constant volume.  
1.2 The test method is intended for use on unused supported platinum on alumina catalysts of loadings greater than 0.3 weight %. Data on other supports and lower platinum loadings were not tested.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The test method has two main functions: first, it provides data useful for establishing the pore size distribution of catalyst materials, which in turn may influence their performance; and second, it serves as a laboratory test which may be used to study porosity changes that may occur during the manufacture and evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of nitrogen adsorption and desorption isotherms of catalysts and catalyst carriers at the boiling point of liquid nitrogen.2 A static volumetric measuring system is used to obtain sufficient equilibrium adsorption points on each branch of the isotherm to adequately define the adsorption and desorption branches of the isotherm. Thirty points evenly spread over the isotherm is considered to be the minimum number of points that will adequately define the isotherm.  
1.2 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ABSTRACT
This test method establishes the standard procedure for determining the surface areas of catalyst and catalyst carriers that have Type II or IV nitrogen adsorption isotherms, and specified minimum area. A volumetric measuring system is used to obtain at least four data points which fit on the linear BET line. The surface area of a catalyst or catalyst carrier is determined by measuring the volume of nitrogen gas adsorbed at various low-pressure levels by the catalyst sample. Pressure differentials caused by introducing the catalyst surface area to a fixed volume of nitrogen in the test apparatus are measured and used to calculate BET surface area.
SCOPE
1.1 This test method covers the determination of surface areas of catalyst and catalyst carriers that have Type II or IV nitrogen adsorption isotherms, and at least 1 m2/g of area. A volumetric measuring system is used to obtain at least four data points which fit on the linear BET2 equation line.  
1.2 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This gas adsorption method complements the X-ray procedure of Test Method D3906. This test method will be useful to laboratories that do not have X-ray diffractometers. Each test method can be calibrated by use of an appropriate series of mechanical mixtures to provide what may be termed percent zeolite. If there is disorder in the zeolite, the adsorption method will yield higher values than the X-ray method. The reverse will be true if some zeolite pores (micropores) are blocked or filled.
SCOPE
1.1 This test method covers the determination of total surface area and mesopore area. From these results are calculated the zeolite area and micropore volume of a zeolite containing catalyst. The micropore volume is related to the percent zeolite in the catalyst. The zeolite area, a number related to the surface area within the zeolite pores, may also be calculated. Zeolite area, however, is difficult to interpret in physical terms because of the manner in which nitrogen molecules pack within the zeolite.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For a specific precautionary statement, see Note 3.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This test method is useful for determining the specific surface area of catalysts and catalyst carriers for material specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the single-point determination of the surface area of catalysts and catalyst carriers that exhibit Type II or Type IV nitrogen adsorption isotherms using a nitrogen-helium flowing gas mixture. This test method is applicable for the determination of total surface areas from 0.1 to 300 m2, where rapid surface area determinations are desired.  
1.2 Because the single-point method uses an approximation of the BET equation, the multipoint BET method (Test Method D3663) is preferred to the single-point method.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 Pore volume distribution curves obtained from nitrogen sorption isotherms provide one of the best means of characterizing the pore structure in porous catalysts, provided that the limitations of the method are kept in mind. Used in conjunction with the BET treatment for surface area determination (5), these methods provide an indispensable means for studying the structure associated with pores usually important in catalysts. This practice is particularly useful in studying changes in a series of closely related samples caused by treatments, such as heat, compression, or extrusion often used in catalyst manufacturing. Pore volume distribution curves can often provide valuable information during mechanistic studies dealing with catalyst deactivation.
SCOPE
1.1 This practice covers the calculation of pore size distributions for catalysts and catalyst carriers from nitrogen desorption isotherms. The computational procedure is particularly useful for determining how the pore volume is distributed in catalyst samples containing pores whose sizes range from approximately 1.5 to 100 nm (15 to 1000 Å) in radius. It should be used with caution when applied to isotherms for samples containing pores both within this size range and pores larger than 100 nm (1000 Å) in radius. In such instances the isotherms rise steeply near P/Po  = 1 and the total pore volume cannot be well defined. The calculations should begin at a point on the isotherm near saturation preferably in a region near P/Po  = 0.99, establishing an upper limit on the pore size distribution range to be studied. Simplifications are necessary regarding pore shape. A cylindrical pore model is assumed, and the method treats the pores as non-intersecting, open-ended capillaries which are assumed to function independently of each other during the adsorption or desorption of nitrogen.  
Note 1: This practice is designed primarily for manual computation and a few simplifications have been made for this purpose. For computer computation, the simplified expressions may be replaced by exact expressions.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This test method is intended to determine the volume distribution of pores in catalysts and catalyst carriers with respect to the apparent diameter of the entrances to the pores. In general, both the size and volume of pores in a catalyst affect its performance. Thus, the pore volume distribution is useful in understanding a catalyst's performance and in specifying a catalyst that can be expected to perform in a desired manner.
SCOPE
1.1 This test method covers the determination of the pore volume distributions of catalysts and catalyst carriers by the method of mercury intrusion porosimetry. The range of apparent diameters of pores for which it is applicable is fixed by the operant pressure range of the testing instrument. This range is typically between apparent pore entrance diameters of about 100 and 0.003 μm (3 nm).  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 WARNING—Mercury has been designated by many regulatory agencies as a hazardous material that can cause central nervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPA’s website—http://www.epa.gov/mercury/faq.htm—for additional information. Users should be aware that selling mercury and/or mercury containing products into your state or country may be prohibited by law.  
1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard information is given in Section 8.

SIGNIFICANCE AND USE
5.1 This test method can be used to determine the acidity of catalysts and catalyst carriers by ammonia chemisorption for materials specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of acidity of catalysts and catalyst carriers by ammonia chemisorption. A volumetric measuring system is used to obtain the amount of chemisorbed ammonia.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This test method has been found useful for the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m2/g for materials specification, manufacturing control, and research and development in the evaluation of catalysts. The determination of surface area of catalysts and catalyst carriers above 10 m2/g is addressed in Test Method D3663.
SCOPE
1.1 This test method covers the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m2/g. A volumetric measuring system is used to obtain at least three data points which fall within the linear BET region.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 This test method is for estimating the relative amount of gamma alumina in calcined catalyst or catalyst carrier samples, assuming that the X-ray powder diffraction peak occurring at about 67 °2θ is attributable to gamma alumina. Gamma alumina is defined as a transition alumina formed after heating in the range from 500 to 550°C, and may include forms described in the literature as eta, chi, and gamma aluminas. Delta alumina has a diffraction peak in the same region, but is formed above 850°C, a temperature to which most catalysts of this type are not heated. There are other possible components which may cause some interference, such as alpha-quartz and zeolite Y, as well as aluminum-containing spinels formed at elevated temperatures. If the presence of interfering material is suspected, the diffraction pattern should be examined in greater detail. More significant interference may be caused by the presence of large amounts of heavy metals or rare earths, which exhibit strong X-ray absorption and scattering. Comparisons between similar materials, therefore, may be more appropriate than those between widely varying materials.
SCOPE
1.1 This test method covers the determination of gamma alumina and related transition aluminas in catalysts and catalyst carriers containing silica and alumina by X-ray powder diffraction, using the diffracted intensity of the peak occurring at about 67 °2θ when copper Kα radiation is employed.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

ABSTRACT
This test method establishes the standard procedure for determining the surface areas of catalyst and catalyst carriers that have Type II or IV nitrogen adsorption isotherms, and specified minimum area. A volumetric measuring system is used to obtain at least four data points which fit on the linear BET line. The surface area of a catalyst or catalyst carrier is determined by measuring the volume of nitrogen gas adsorbed at various low-pressure levels by the catalyst sample. Pressure differentials caused by introducing the catalyst surface area to a fixed volume of nitrogen in the test apparatus are measured and used to calculate BET surface area.
SCOPE
1.1 This test method covers the determination of surface areas of catalyst and catalyst carriers that have Type II or IV nitrogen adsorption isotherms, and at least 1 m2/g of area. A volumetric measuring system is used to obtain at least four data points which fit on the linear BET2 equation line.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 This test method sets forth a procedure by which duplicate catalyst samples can be compared either on an interlaboratory or intralaboratory basis. It is anticipated that catalyst producers and users will find this test method of value.  
4.2 Discrimination of the samples for which this procedure is recommended must be exercised when considering carrier (support) materials that sorb appreciable quantities of hydrogen or could cause an alteration of the state of the catalyst during pretreatment, or both, (that is, sintering or metal occlusion). These materials must be identified by the user and experimented with to determine the most significant conditions of measurement.  
4.3 This test method provides a measure of the total hydrogen uptake (volume of hydrogen at STP, cm3/g of catalyst) without specifying the nature of the hydrogen-platinum interaction. Persons interested in using hydrogen uptake data to calculate percent platinum dispersion in a specific catalyst should be aware of carrier (support) interactions, spillover effects, and other phenomena related to the hydrogen uptake capabilities of the catalyst in question.
SCOPE
1.1 This test method covers the determination of the chemisorption of hydrogen at 298 K (25°C) on supported platinum catalysts that have been reduced in flowing hydrogen at 723 K (450°C). It incorporates a static volumetric vacuum technique at constant volume.  
1.2 The test method is intended for use on unused supported platinum on alumina catalysts of loadings greater than 0.3 weight %. Data on other supports and lower platinum loadings were not tested.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The test method has two main functions: first, it provides data useful for establishing the pore size distribution of catalyst materials, which in turn may influence their performance; and second, it serves as a laboratory test which may be used to study porosity changes that may occur during the manufacture and evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of nitrogen adsorption and desorption isotherms of catalysts and catalyst carriers at the boiling point of liquid nitrogen.2 A static volumetric measuring system is used to obtain sufficient equilibrium adsorption points on each branch of the isotherm to adequately define the adsorption and desorption branches of the isotherm. Thirty points evenly spread over the isotherm is considered to be the minimum number of points that will adequately define the isotherm.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This test method is useful for determining the specific surface area of catalysts and catalyst carriers for material specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the single-point determination of the surface area of catalysts and catalyst carriers that exhibit Type II or Type IV nitrogen adsorption isotherms using a nitrogen-helium flowing gas mixture. This test method is applicable for the determination of total surface areas from 0.1 to 300 m2, where rapid surface area determinations are desired.  
1.2 Because the single-point method uses an approximation of the BET equation, the multipoint BET method (Test Method D3663) is preferred to the single-point method.Note 1—This is particularly true when testing microporous materials.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This test method can be used to determine the acidity of catalysts and catalyst carriers by ammonia chemisorption for materials specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of acidity of catalysts and catalyst carriers by ammonia chemisorption. A volumetric measuring system is used to obtain the amount of chemisorbed ammonia.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This gas adsorption method complements the X-ray procedure of Test Method D3906. This test method will be useful to laboratories that do not have X-ray diffractometers. Each test method can be calibrated by use of an appropriate series of mechanical mixtures to provide what may be termed percent zeolite. If there is disorder in the zeolite, the adsorption method will yield higher values than the X-ray method. The reverse will be true if some zeolite pores (micropores) are blocked or filled.
SCOPE
1.1 This test method covers the determination of total surface area and mesopore area. From these results are calculated the zeolite area and micropore volume of a zeolite containing catalyst. The micropore volume is related to the percent zeolite in the catalyst. The zeolite area, a number related to the surface area within the zeolite pores, may also be calculated. Zeolite area, however, is difficult to intepret in physical terms because of the manner in which nitrogen molecules pack within the zeolite.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific precautionary statement, see Note 3.

SIGNIFICANCE AND USE
This test method is intended to determine the volume distribution of pores in catalysts and catalyst carriers with respect to the apparent diameter of the entrances to the pores. In general, both the size and volume of pores in a catalyst affect its performance. Thus, the pore volume distribution is useful in understanding a catalyst's performance and in specifying a catalyst that can be expected to perform in a desired manner.
SCOPE
1.1 This test method covers the determination of the pore volume distributions of catalysts and catalyst carriers by the method of mercury intrusion porosimetry. The range of apparent diameters of pores for which it is applicable is fixed by the operant pressure range of the testing instrument. This range is typically between apparent pore entrance diameters of about 100 and 0.003 μm (3 nm).
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 WARNINGMercury has been designated by many regulatory agencies as a hazardous material that can cause central nervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPA’s websitehttp://www.epa.gov/mercury/faq.htmfor additional information. Users should be aware that selling mercury and/or mercury containing products into your state or country may be prohibited by law.
1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard information is given in Section 8.

SIGNIFICANCE AND USE
Pore volume distribution curves obtained from nitrogen sorption isotherms provide one of the best means of characterizing the pore structure in porous catalysts, provided that the limitations of the method are kept in mind. Used in conjunction with the BET treatment for surface area determination (4), these methods provide an indispensable means for studying the structure associated with pores usually important in catalysts. This practice is particularly useful in studying changes in a series of closely related samples caused by treatments, such as heat, compression, or extrusion often used in catalyst manufacturing. Pore volume distribution curves can often provide valuable information during mechanistic studies dealing with catalyst deactivation.
SCOPE
1.1 This practice covers the calculation of pore size distributions for catalysts and catalyst carriers from nitrogen desorption isotherms. The computational procedure is particularly useful for determining how the pore volume is distributed in catalyst samples containing pores whose sizes range from approximately 1.5 to 100 nm (15 to 1000 �) in radius. It should be used with caution when applied to isotherms for samples containing pores both within this size range and pores larger than 100 nm (1000 �) in radius. In such instances the isotherms rise steeply near P/Po  = 1 and the total pore volume cannot be well defined. The calculations should be begun at a point on the isotherm near saturation preferably in a region near P/Po  = 0.99, establishing an upper limit on the pore size distribution range to be studied. Simplifications are necessary regarding pore shape. A cylindrical pore model is assumed, and the method treats the pores as non-intersecting, open-ended capillaries which are assumed to function independently of each other during the adsorption or desorption of nitrogen.
Note 1—This practice is designed primarily for manual computation and a few simplifications have been made for this purpose. For computer computation, the simplified expressions may be replaced by exact expressions.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method has been found useful for the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m2/g for materials specification, manufacturing control, and research and development in the evaluation of catalysts. The determination of surface area of catalysts and catalyst carriers above 10 m2/g is addressed in Test Method D3663.
SCOPE
1.1 This test method covers the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m2/g. A volumetric measuring system is used to obtain at least three data points which fall within the linear BET region.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method is for estimating the relative amount of gamma alumina in calcined catalyst samples, assuming that the X-ray powder diffraction peak occurring at about 67 °2θ is attributable to gamma alumina. Gamma alumina is defined as a transition alumina formed after heating in the range from 500 to 550°C, and may include forms described in the literature as eta, chi, and gamma aluminas. Delta alumina has a diffraction peak in the same region, but is formed above 850°C, a temperature to which most catalysts of this type are not heated. There are other possible components which may cause some interference, such as alpha-quartz and zeolite Y, as well as aluminum-containing spinels formed at elevated temperatures. If the presence of interfering material is suspected, the diffraction pattern should be examined in greater detail. More significant interference may be caused by the presence of large amounts of heavy metals or rare earths, which exhibit strong X-ray absorption and scattering. Comparisons between similar materials, therefore, may be more appropriate than those between widely varying materials.
SCOPE
1.1 This test method covers the determination of gamma alumina and related transition aluminas in catalysts containing silica and alumina by X-ray powder diffraction, using the diffracted intensity of the peak occurring at about 67 °2θ when copper Kα radiation is employed.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method is useful for determining the specific surface area of catalysts and catalyst carriers for material specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the single-point determination of the surface area of catalysts and catalyst carriers that exhibit Type II or Type IV nitrogen adsorption isotherms using a nitrogen-helium flowing gas mixture. This test method is applicable for the determination of total surface areas from 0.1 to 300 m2, where rapid surface area determinations are desired.
1.2 Because the single-point method uses an approximation of the BET equation, the multipoint BET method (Test Method D 3663) is preferred to the single-point method.
Note 1—This is particularly true when testing microporous materials.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
The test method has two main functions: first, it provides data useful for establishing the pore size distribution of catalyst materials, which in turn may influence their performance; and second, it serves as a laboratory test which may be used to study porosity changes that may occur during the manufacture and evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of nitrogen adsorption and desorption isotherms of catalysts and catalyst carriers at the boiling point of liquid nitrogen. A static volumetric measuring system is used to obtain sufficient equilibrium adsorption points on each branch of the isotherm to adequately define the adsorption and desorption branches of the isotherm. Thirty points evenly spread over the isotherm is considered to be the minimum number of points that will adequately define the isotherm.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This gas adsorption method complements the X-ray procedure of Test Method D 3906. This test method will be useful to laboratories that do not have X-ray diffractometers. Each test method can be calibrated by use of an appropriate series of mechanical mixtures to provide what may be termed percent zeolite. If there is disorder in the zeolite, the adsorption method will yield higher values than the X-ray method. The reverse will be true if some zeolite pores (micropores) are blocked or filled.
SCOPE
1.1 This test method covers the determination of total surface area and mesopore area. From these results are calculated the zeolite area and micropore volume of a zeolite containing catalyst. The micropore volume is related to the percent zeolite in the catalyst. The zeolite area, a number related to the surface area within the zeolite pores, may also be calculated. Zeolite area, however, is difficult to intepret in physical terms because of the manner in which nitrogen molecules pack within the zeolite.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific precautionary statement, see Note 3.

SIGNIFICANCE AND USE
This test method sets forth a procedure by which duplicate catalyst samples can be compared either on an interlaboratory or intralaboratory basis. It is anticipated that catalyst producers and users will find this test method of value.
Discrimination of the samples for which this procedure is recommended must be exercised when considering carrier (support) materials that sorb appreciable quantities of hydrogen or could cause an alteration of the state of the catalyst during pretreatment, or both, (that is, sintering or metal occlusion). These materials must be identified by the user and experimented with to determine the most significant conditions of measurement.
This test method provides a measure of the total hydrogen uptake (volume of hydrogen at STP, cm3/g of catalyst) without specifying the nature of the hydrogen-platinum interaction. Persons interested in using hydrogen uptake data to calculate percent platinum dispersion in a specific catalyst should be aware of carrier (support) interactions, spillover effects, and other phenomena related to the hydrogen uptake capabilities of the catalyst in question.
SCOPE
1.1 This test method covers the determination of the chemisorption of hydrogen at 298 K (25°C) on supported platinum catalysts that have been reduced in flowing hydrogen at 723 K (450°C). It incorporates a static volumetric vacuum technique at constant volume.
1.2 The test method is intended for use on unused supported platinum on alumina catalysts of loadings greater than 0.3 weight %. Data on other supports and lower platinum loadings were not tested.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method can be used to determine the acidity of catalysts and catalyst carriers by ammonia chemisorption for materials specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of acidity of catalysts and catalyst carriers by ammonia chemisorption. A volumetric measuring system is used to obtain the amount of chemisorbed ammonia.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

ABSTRACT
This test method establishes the standard procedure for determining the surface areas of catalyst and catalyst carriers that have Type II or IV nitrogen adsorption isotherms, and specified minimum area. A volumetric measuring system is used to obtain at least four data points which fit on the linear BET line. The surface area of a catalyst or catalyst carrier is determined by measuring the volume of nitrogen gas adsorbed at various low-pressure levels by the catalyst sample. Pressure differentials caused by introducing the catalyst surface area to a fixed volume of nitrogen in the test apparatus are measured and used to calculate BET surface area.
SCOPE
1.1 This test method covers the determination of surface areas of catalyst and catalyst carriers that have Type II or IV nitrogen adsorption isotherms, and at least 1 m2/g of area. A volumetric measuring system is used to obtain at least four data points which fit on the linear BET line.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method has been found useful for the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m2/g for materials specification, manufacturing control, and research and development in the evaluation of catalysts. The determination of surface area of catalysts and catalyst carriers above 10 m2/g is addressed in Test Method D 3663.
SCOPE
1.1 This test method covers the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m2/g. A volumetric measuring system is used to obtain at least three data points which fall within the linear BET region.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This gas adsorption method complements the X-ray procedure of Test Method D 3906. This test method will be useful to laboratories that do not have X-ray diffractometers. Each test method can be calibrated by use of an appropriate series of mechanical mixtures to provide what may be termed percent zeolite. If there is disorder in the zeolite, the adsorption method will yield higher values than the X-ray method. The reverse will be true if some zeolite pores (micropores) are blocked or filled.
SCOPE
1.1 This test method covers the determination of total surface area and mesopore area. From these results are calculated the zeolite area and micropore volume of a zeolite containing catalyst. The micropore volume is related to the percent zeolite in the catalyst. The zeolite area, a number related to the surface area within the zeolite pores, may also be calculated. Zeolite area, however, is difficult to intepret in physical terms because of the manner in which nitrogen molecules pack within the zeolite.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific precautionary statement, see Note 3.

SIGNIFICANCE AND USE
This test method is intended to determine the volume distribution of pores in catalysts with respect to the apparent diameter of the entrances to the pores. In general, both the size and volume of pores in a catalyst affect its performance. Thus, the pore volume distribution is useful in understanding a catalyst’performance and in specifying a catalyst that can be expected to perform in a desired manner.
SCOPE
1.1 This test method covers the determination of the pore volume distributions of catalysts and catalyst supports by the method of mercury intrusion porosimetry. The range of apparent diameters of pores for which it is applicable is fixed by the operant pressure range of the testing instrument. This range is typically between apparent pore entrance diameters of about 100 and 0.003 m (3 nm).
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard information is given in Section 8.

SIGNIFICANCE AND USE
Pore volume distribution curves obtained from nitrogen sorption isotherms provide one of the best means of characterizing the pore structure in porous catalysts, provided that the limitations of the method are kept in mind. Used in conjunction with the BET treatment for surface area determination (4), these methods provide an indispensable means for studying the structure associated with pores usually important in catalysts. This practice is particularly useful in studying changes in a series of closely related samples caused by treatments, such as heat, compression, or extrusion often used in catalyst manufacturing. Pore volume distribution curves can often provide valuable information during mechanistic studies dealing with catalyst deactivation.
SCOPE
1.1 This practice covers the calculation of pore size distributions for catalysts and catalyst carriers from nitrogen desorption isotherms. The computational procedure is particularly useful for determining how the pore volume is distributed in catalyst samples containing pores whose sizes range from approximately 1.5 to 100 nm (15 to 1000 ) in radius. It should be used with caution when applied to isotherms for samples containing pores both within this size range and pores larger than 100 nm (1000 ) in radius. In such instances the isotherms rise steeply near  P/Po  = 1 and the total pore volume cannot be well defined. The calculations should be begun at a point on the isotherm near saturation preferably in a region near P/Po  = 0.99, establishing an upper limit on the pore size distribution range to be studied. Simplifications are necessary regarding pore shape. A cylindrical pore model is assumed, and the method treats the pores as non-intersecting, open-ended capillaries which are assumed to function independently of each other during the adsorption or desorption of nitrogen. Note 1 - This practice is designed primarily for manual computation and a few simplifications have been made for this purpose. For computer computation, the simplified expressions may be replaced by exact expressions.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method is for estimating the relative amount of gamma alumina in calcined catalyst samples, assuming that the X-ray powder diffraction peak occurring at about 67 °2θ is attributable to gamma alumina. Gamma alumina is defined as a transition alumina formed after heating in the range from 500 to 550°C, and may include forms described in the literature as eta, chi, and gamma aluminas. Delta alumina has a diffraction peak in the same region, but is formed above 850°C, a temperature to which most catalysts of this type are not heated. There are other possible components which may cause some interference, such as alpha-quartz and zeolite Y, as well as aluminum-containing spinels formed at elevated temperatures. If the presence of interfering material is suspected, the diffraction pattern should be examined in greater detail. More significant interference may be caused by the presence of large amounts of heavy metals or rare earths, which exhibit strong X-ray absorption and scattering. Comparisons between similar materials, therefore, may be more appropriate than those between widely varying materials.
SCOPE
1.1 This test method covers the determination of gamma alumina and related transition aluminas in catalysts containing silica and alumina by X-ray powder diffraction, using the diffracted intensity of the peak occurring at about 67 2 when copper K radiation is employed.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
The test method has two main functions: first, it provides data useful for establishing the pore size distribution of catalyst materials, which in turn may influence their performance; and second, it serves as a laboratory test which may be used to study porosity changes that may occur during the manufacture and evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of nitrogen adsorption and desorption isotherms of catalysts and catalyst carriers at the boiling point of liquid nitrogen. A static volumetric measuring system is used to obtain sufficient equilibrium adsorption points on each branch of the isotherm to adequately define the adsorption and desorption branches of the isotherm. Thirty points evenly spread over the isotherm is considered to be the minimum number of points that will adequately define the isotherm.
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method sets forth a procedure by which duplicate catalyst samples can be compared either on an interlaboratory or intralaboratory basis. It is anticipated that catalyst producers and users will find this test method of value.
Discrimination of the samples for which this procedure is recommended must be exercised when considering carrier (support) materials that sorb appreciable quantities of hydrogen or could cause an alteration of the state of the catalyst during pretreatment, or both, (that is, sintering or metal occlusion). These materials must be identified by the user and experimented with to determine the most significant conditions of measurement.
This test method provides a measure of the total hydrogen uptake (volume of hydrogen at STP, cm3/g of catalyst) without specifying the nature of the hydrogen-platinum interaction. Persons interested in using hydrogen uptake data to calculate percent platinum dispersion in a specific catalyst should be aware of carrier (support) interactions, spill-over effects, and other phenomena related to the hydrogen uptake capabilities of the catalyst in question.
SCOPE
1.1 This test method covers the determination of the chemisorption of hydrogen at 298 K (25°C) on supported platinum catalysts that have been reduced in flowing hydrogen at 723 K (450°C). It incorporates a static volumetric vacuum technique at constant volume.
1.2 The test method is intended for use on unused supported platinum on alumina catalysts of loadings greater than 0.3 weight %. Data on other supports and lower platinum loadings were not tested.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method is useful for determining the specific surface area of catalysts and catalyst carriers for material specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the single-point determination of the surface area of catalysts and catalyst carriers that exhibit Type II or Type IV nitrogen adsorption isotherms using a nitrogen-helium flowing gas mixture. This test method is applicable for the determination of total surface areas from 0.1 to 300 m2, where rapid surface area determinations are desired.
1.2 Because the single-point method uses an approximation of the BET equation, the multipoint BET method (Test Method D 3663) is preferred to the single-point method.
Note 1—This is particularly true when testing microporous materials.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the determination of surface areas of catalyst and catalyst carriers that have Type II or IV nitrogen adsorption isotherms, and at least 1 m2/g of area. A volumetric measuring system is used to obtain at least four data points which fit on the linear BET line.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method can be used to determine the acidity of catalysts and catalyst carriers by ammonia chemisorption for materials specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of acidity of catalysts and catalyst carriers by ammonia chemisorption. A volumetric measuring system is used to obtain the amount of chemisorbed ammonia.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the determination of the pore volume distributions of catalysts and catalyst supports by the method of mercury intrusion porosimetry. The range of apparent diameters of pores for which it is applicable is fixed by the operant pressure range of the testing instrument. This range is typically between apparent pore entrance diameters of about 100 and 0.003 m (3 nm).
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only.
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 8.

SCOPE
1.1 This test method covers the determination of acidity of catalysts and catalyst carriers by ammonia chemisorption. A volumetric measuring system is used to obtain the amount of chemisorbed ammonia.
1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the determination of surface areas of catalyst and catalyst carriers that have Type II or IV nitrogen adsorption isotherms, and at least 1 m /g of area. A volumetric measuring system is used to obtain at least four data points which fit on the linear BET  line.  
1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the determination of the chemisorption of hydrogen at 298 K (25°C) on supported platinum catalysts that have been reduced in flowing hydrogen at 723 K (450°C). It incorporates a static volumetric vacuum technique at constant volume.  
1.2 The test method is intended for use on unused supported platinum on alumina catalysts of loadings greater than 0.3 weight %. Data on other supports and lower platinum loadings were not tested.
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the single-point determination of the surface area of catalysts and catalyst carriers that exhibit Type II or Type IV nitrogen adsorption isotherms using a nitrogen-helium flowing gas mixture. This test method is applicable for the determination of total surface areas from 0.1 to 300 m , where rapid surface area determinations are desired.  
1.2 Since the single-point method uses an approximation of the BET equation, the multipoint BET method (D3663) is preferred to the single-point method.  
1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This practice covers the calculation of pore size distributions for catalysts and catalyst carriers from nitrogen desorption isotherms. The computational procedure is particularly useful for determining how the pore volume is distributed in catalyst samples containing pores whose sizes range from approximately 15 to 1000 Å (10 Å-1 nm) in radius. It should be used with caution when applied to isotherms for samples containing pores both within this size range and pores larger than 1000 Å in radius. In such instances the isotherms rise steeply near / Po = 1 and the total pore volume cannot be well defined. The calculations should be begun at a point on the isotherm near saturation preferably in a region near / Po = 0.99, establishing an upper limit on the pore size distribution range to be studied. Simplifications are necessary regarding pore shape. A cylindrical pore model is assumed, and the method treats the pores as non-intersecting, open-ended capillaries which are assumed to function independently of each other during the adsorption or desorption of nitrogen. Note 1-This practice is designed primarily for manual computation and a few simplifications have been made for this purpose. For computer computation the simplified expressions may be replaced by exact expressions.
1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the determination of nitrogen adsorption and desorption isotherms of catalysts and catalyst carriers at the boiling point of liquid nitrogen. A static volumetric measuring system is used to obtain about thirty equilibrium adsorption points on each branch of the isotherm, these points being evenly spread over the isotherm.
1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m/g. A volumetric measuring system is used to obtain at least three data points which fall within the linear BET region.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the determination of total surface area and mesopore area. From these results are calculated the zeolite area and micropore volume of a zeolite containing catalyst. The micropore volume is related to the percent zeolite in the catalyst. The zeolite area, a number related to the surface area within the zeolite pores, may also be calculated. Zeolite area, however, is difficult to intepret in physical terms because of the manner in which nitrogen molecules pack within the zeolite.  
1.2  This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  For specific precautionary statement, see Note 2.

SCOPE
1.1 This test method covers the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m/g. A volumetric measuring system is used to obtain at least three data points which fall within the linear BET region.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.