ASTM D4365-19
(Test Method)Standard Test Method for Determining Micropore Volume and Zeolite Area of a Catalyst
Standard Test Method for Determining Micropore Volume and Zeolite Area of a Catalyst
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.
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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.
Designation: D4365 − 19
Standard Test Method for
Determining Micropore Volume and Zeolite Area of a
1
Catalyst
This standard is issued under the fixed designation D4365; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Containing Materials
E177Practice for Use of the Terms Precision and Bias in
1.1 This test method covers the determination of total
ASTM Test Methods
surface area and mesopore area. From these results are calcu-
E456Terminology Relating to Quality and Statistics
lated the zeolite area and micropore volume of a zeolite
E691Practice for Conducting an Interlaboratory Study to
containing catalyst. The micropore volume is related to the
Determine the Precision of a Test Method
percent zeolite in the catalyst. The zeolite area, a number
relatedtothesurfaceareawithinthezeolitepores,mayalsobe
3. Terminology
calculated. Zeolite area, however, is difficult to interpret in
physical terms because of the manner in which nitrogen 3.1 Definitions of Terms Specific to This Standard:
molecules pack within the zeolite.
3.1.1 micropore volume of the catalyst, n—the pore volume
inporeshavingradiilessthan1nm,usuallyassociatedwiththe
1.2 The values stated in SI units are to be regarded as
zeolite portion of the catalyst, and determined from the
standard. No other units of measurement are included in this
intercept of the t-plot.
standard.
3.1.2 surface area of a catalyst, n—the total surface of the
1.3 This standard does not purport to address all of the
catalyst obtained from the BET method.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.1.2.1 Discussion—Surface area may be used interchange-
priate safety, health, and environmental practices and deter-
ably with BET area. It is expressed in square meters per gram.
mine the applicability of regulatory limitations prior to use.
3.1.3 t-area of the catalyst, n—theareadeterminedfromthe
For a specific precautionary statement, see Note 3.
slope of the t-plot.
1.4 This international standard was developed in accor-
3.1.3.1 Discussion—t-area may be used interchangeably
dance with internationally recognized principles on standard-
with matrix area or external surface area. It is expressed in
ization established in the Decision on Principles for the
square meters per gram.
Development of International Standards, Guides and Recom-
3.1.4 zeolite area of a catalyst, n—the difference between
mendations issued by the World Trade Organization Technical
total surface area and mesopore area.
Barriers to Trade (TBT) Committee.
3.1.4.1 Discussion—The zeolite area may be used inter-
2. Referenced Documents
changeably with micropore area. It is expressed in square
2
2.1 ASTM Standards:
meters per gram.
D3663Test Method for Surface Area of Catalysts and
3.2 Symbols:
Catalyst Carriers
D3906Test Method for Determination of Relative X-ray
P = initial helium pressure, torr
Diffraction Intensities of Faujasite-Type Zeolite-
H
1
P = helium pressure after equilibration, torr
H
2
S = slope of BET plot, 11.7
B
1
This test method is under the jurisdiction of ASTM Committee D32 on I = intercept of BET plot, 11.7
B
Catalysts and is the direct responsibility of Subcommittee D32.01 on Physical-
A = BET area, 11.9
B
Chemical Properties.
N = Avogadro’s number
CurrenteditionapprovedJuly1,2019.PublishedJuly2019.Originallyapproved
A = Cross-sectional area of adsorbed nitrogen mol-
CS
in 1984. Last previous edition approved in 2013 as D4365–13. DOI: 10.1520/
ecule
D4365-19.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
S = slope of t-plot, 11.13
t
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
I = intercept of t-plot, 11.13
t
Standards volume information, refer to the standard’s Document Summary page on
A = t-area
t
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D4365 − 19
FIG. 1 Schematic Diagram of Surface Area Apparatus
Each test method can be calibrated by use of an appropriate
T = temperatureofmanifoldatinitialheliumpressure,
H1
series of mechanical mixtures to provide what may be termed
°C
percentzeolite.Ifthereisdisorderinthezeolite,theadsorption
T = temperature of manifold after equilibration, °C
H2
T '(i) = extra volume bulb temperature, °C method will yi
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D4365 − 13 D4365 − 19
Standard Test Method for
Determining Micropore Volume and Zeolite Area of a
1
Catalyst
This standard is issued under the fixed designation D4365; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. 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 intepretinterpret 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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D3663 Test Method for Surface Area of Catalysts and Catalyst Carriers
D3906 Test Method for Determination of Relative X-ray Diffraction Intensities of Faujasite-Type Zeolite-Containing Materials
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 mesopore (matrix) area of a catalyst—the area determined from the slope of the t-plot.
3.1.1 micropore volume of the catalyst—catalyst, n—the pore volume in pores having radii less than 1 nm, usually associated
with the zeolite portion of the catalyst, and determined from the intercept of the t-plot.
3.1.2 surface area of a catalyst—catalyst, n—the total surface of the catalyst pores. It is expressed in square metres per
gram.obtained from the BET method.
1
This test method is under the jurisdiction of ASTM Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.01 on Physical-Chemical
Properties.
Current edition approved April 1, 2013July 1, 2019. Published August 2013July 2019. Originally approved in 1984. Last previous edition approved in 20082013 as
D4365 – 95D4365 – 13.(2008). DOI: 10.1520/D4365-13.10.1520/D4365-19.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3.1.2.1 Discussion—
Surface area may be used interchangeably with BET area. It is expressed in square meters per gram.
3.1.3 t-area of the catalyst, n—the area determined from the slope of the t-plot.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D4365 − 19
3.1.3.1 Discussion—
t-area may be used interchangeably with matrix area or external surface area. It is expressed in square meters per gram.
3.1.4 zeolite area of a catalyst—catalyst, n—the difference between total surface area and mesopore area.
3.1.4.1 Discussion—
The zeolite area may be used interchangeably with micropore area. It is expressed in square meters per gram.
3.2 Symbols:
P = initial helium pressure, torr
H
1
P = helium pressure after equilibration, torr
H
2
S = slope of BET plot, 11.7
B
I = intercept of BET plot, 11.7
B
A = BET area, 11.9
B
N = Avogadro’s number
A = Cross-sectional area of adsorbed nitrogen molecule
CS
S = slope of t-plot, 11.13
t
I = intercept of t-plot, 11.13
...
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