ASTM D4926-20
(Test Method)Standard Test Method for Gamma Alumina Content in Catalysts and Catalyst Carriers Containing Silica and Alumina by X-ray Powder Diffraction
Standard Test Method for Gamma Alumina Content in Catalysts and Catalyst Carriers Containing Silica and Alumina by X-ray Powder Diffraction
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.
General Information
- Status
- Published
- Publication Date
- 30-Sep-2020
- Technical Committee
- D32 - Catalysts
- Drafting Committee
- D32.01 - Physical-Chemical Properties
Relations
- Effective Date
- 01-May-2013
- Effective Date
- 01-Nov-2011
- Effective Date
- 01-Oct-2008
- Effective Date
- 01-Nov-2005
- Effective Date
- 10-May-1999
Overview
ASTM D4926-20: Standard Test Method for Gamma Alumina Content in Catalysts and Catalyst Carriers Containing Silica and Alumina by X-ray Powder Diffraction outlines a precise method for estimating the relative amount of gamma alumina within calcined catalyst or catalyst carrier samples. This test method utilizes X-ray powder diffraction (XRD), specifically focusing on the diffracted intensity of the characteristic peak near 67 °2θ when copper Kα radiation is used.
Gamma alumina, a transition alumina formed after heat treatment typically between 500 to 550 °C, is a crucial component in many industrial catalytic processes. This standard ensures consistent and reliable quantification of gamma alumina, enhancing the quality assurance and comparison of materials used in catalyst manufacturing and research.
Key Topics
- Gamma Alumina Identification: Focuses on the identification and quantification of gamma alumina and related transition aluminas (such as eta and chi forms) using X-ray powder diffraction, targeting the 67 °2θ peak.
- Sample Preparation: Includes procedures for calcining, grinding, and mounting catalyst samples to ensure consistency and accuracy in measurement.
- Interference and Limitations: Recognizes possible interfering phases, such as delta alumina, alpha-quartz, zeolite Y, and aluminum-containing spinels, which may complicate interpretation of results. It also notes the impact of heavy metals and rare earths on XRD data due to their strong X-ray absorption and scattering.
- Reliability of Results: Encourages comparison between similar materials to ensure meaningful evaluation, particularly given potential sample-specific interference.
- Calculation Methods: Provides a method for calculating the relative gamma alumina content based on the measured peak intensity, width at half-height, and instrument gain factors, using reference materials for calibration.
Applications
The ASTM D4926-20 standard is widely used in the petrochemical, chemical processing, and materials science industries for:
- Catalyst Quality Control: Ensures that manufactured catalysts and supports meet required specifications for gamma alumina content, which affects activity, selectivity, and stability of catalytic processes.
- Research and Development: Provides a reliable method for benchmarking new catalyst materials and for studying the effects of processing parameters on alumina phases within catalyst carriers.
- Comparison of Materials: Allows laboratories, manufacturers, and end-users to compare the gamma alumina content of various catalyst batches or research materials, provided they are similar in composition.
- Regulatory and Specification Compliance: Assists in maintaining compliance with industry standards or regulatory requirements where alumina phase composition is critical.
Related Standards
Professionals using ASTM D4926-20 may also find the following standards relevant:
- ASTM E691 - Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method (cited for reproducibility analysis).
- ASTM D3906 - Standard Practice for Sampling and Preparation of Catalyst and Catalyst Carrier Samples.
- ISO 9001 - International Standard for Quality Management Systems, relevant for ensuring standardized laboratory practices.
- Other XRD Methods - Standards related to X-ray powder diffraction for material analysis.
Keywords: gamma alumina, catalyst carrier, X-ray powder diffraction, ASTM D4926-20, alumina content, silica, catalyst quality control, industrial catalysts, alumina phases, materials testing, transition alumina, catalyst analysis.
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ASTM D4926-20 - Standard Test Method for Gamma Alumina Content in Catalysts and Catalyst Carriers Containing Silica and Alumina by X-ray Powder Diffraction
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Frequently Asked Questions
ASTM D4926-20 is a standard published by ASTM International. Its full title is "Standard Test Method for Gamma Alumina Content in Catalysts and Catalyst Carriers Containing Silica and Alumina by X-ray Powder Diffraction". This standard covers: 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 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.
ASTM D4926-20 is classified under the following ICS (International Classification for Standards) categories: 71.040.30 - Chemical reagents. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM D4926-20 has the following relationships with other standards: It is inter standard links to ASTM E691-13, ASTM E691-11, ASTM E691-08, ASTM E691-05, ASTM E691-99. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ASTM D4926-20 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
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: D4926 − 20
Standard Test Method for
Gamma Alumina Content in Catalysts and Catalyst Carriers
Containing Silica and Alumina by X-ray Powder Diffraction
This standard is issued under the fixed designation D4926; 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 reference sample, after appropriate adjustments are made for
scale settings and peak half-widths.
1.1 This test method covers the determination of gamma
alumina and related transition aluminas in catalysts and cata-
4. Significance and Use
lyst carriers containing silica and alumina by X-ray powder
4.1 This test method is for estimating the relative amount of
diffraction, using the diffracted intensity of the peak occurring
gamma alumina in calcined catalyst or catalyst carrier samples,
at about 67 °2θ when copper Kα radiation is employed.
assuming that the X-ray powder diffraction peak occurring at
1.2 Units—The values stated in SI units are to be regarded
about 67 °2θ is attributable to gamma alumina. Gamma
as standard. No other units of measurement are included in this
alumina is defined as a transition alumina formed after heating
standard.
in the range from 500 to 550 °C, and may include forms
1.3 This standard does not purport to address all of the
described in the literature as eta, chi, and gamma aluminas.
safety concerns, if any, associated with its use. It is the
Delta alumina has a diffraction peak in the same region, but is
responsibility of the user of this standard to establish appro-
formed above 850 °C, a temperature to which most catalysts of
priate safety, health, and environmental practices and deter-
this type are not heated. There are other possible components
mine the applicability of regulatory limitations prior to use.
which may cause some interference, such as alpha-quartz and
1.4 This international standard was developed in accor-
zeolite Y, as well as aluminum-containing spinels formed at
dance with internationally recognized principles on standard-
elevated temperatures. If the presence of interfering material is
ization established in the Decision on Principles for the
suspected,thediffractionpatternshouldbeexaminedingreater
Development of International Standards, Guides and Recom-
detail. More significant interference may be caused by the
mendations issued by the World Trade Organization Technical
presenceoflargeamountsofheavymetalsorrareearths,which
Barriers to Trade (TBT) Committee.
exhibit strong X-ray absorption and scattering. Comparisons
between similar materials, therefore, may be more appropriate
2. Referenced Documents
than those between widely varying materials.
2.1 ASTM Standards:
5. Apparatus
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
5.1 X-ray Powder Diffractometer Unit, with standard
sample mount, Cu Kα radiation, monochromator, wide diver-
3. Summary of Test Method
gence and receiving slits (for example, 3° and 0.15°,
respectively), goniometer speed of 0.5°/min or equivalent,
3.1 A sample of catalyst or catalyst carrier is calcined and
ground, and an X-ray powder diffraction pattern is obtained chart speed of about 0.5 cm⁄min or equivalent, and scale or
gain factors to provide conveniently measurable peaks. Com-
under specified conditions over the approximate range from 52
to 76 °2θ. The diffracted intensity above background for the puterized data acquisition equipment may also be used.
peak occurring at about 67 °2θ is compared to that of a
NOTE 1—For diffractometers employing step scanning, convenient
corresponding conditions include a step size of 0.02° and a counting time
of 2.4 s ⁄step, which is equivalent to a scanning rate of 0.5°/min.
This test method is under the jurisdiction of ASTM Committee D32 on
5.2 Calcination Furnace.
Catalysts and is the direct responsibility of Subcommittee D32.01 on Physical-
Chemical Properties.
5.3 Grinding Equipment, suitable for preparing samples for
Current edition approved Oct. 1, 2020. Published October 2020. Originally
mounting in the sample holder.
approved in 1989. Last previous edition approved in 2015 as D4926 – 15. DOI:
10.1520/D4926-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 6. Procedure
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.1 Calcine the catalyst or catalyst carrier sample for 3 h at
Standards volume information, refer to the standa
...
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: D4926 − 15 D4926 − 20
Standard Test Method for
Gamma Alumina Content in Catalysts and Catalyst Carriers
Containing Silica and Alumina by X-ray Powder Diffraction
This standard is issued under the fixed designation D4926; 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 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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2.1 ASTM Standards:
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Summary of Test Method
3.1 A sample of catalyst or catalyst carrier is calcined and ground, and an X-ray powder diffraction pattern is obtained under
specified conditions over the approximate range from 52 to 76 °2θ. The diffracted intensity above background for the peak
occurring at about 67 °2θ is compared to that of a reference sample, after appropriate adjustments are made for scale settings and
peak half-widths.
4. 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
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 Dec. 1, 2015Oct. 1, 2020. Published January 2016October 2020. Originally approved in 1989. Last previous edition approved in 20112015 as
D4926–06(2011).D4926 – 15. DOI: 10.1520/D4926-15.10.1520/D4926-20.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4926 − 20
defined as a transition alumina formed after heating in the range from 500 to 550°C,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,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.
5. Apparatus
5.1 X-ray Powder Diffractometer Unit, with standard sample mount, Cu Kα radiation, monochromator, wide divergence and
receiving slits (for example, 3° and 0.15°, respectively), goniometer speed of 0.5°/min or equivalent, chart speed of about
0.50.5 cm cm/min ⁄min or equivalent, and scale or gain factors to provide conveniently measurable peaks. Computerized data
acquisition equipment may also be used.
NOTE 1—For diffractometers employing step scanning, convenient corresponding conditions include a step size of 0.02° and a counting time of 2.42.4 s
s/step, ⁄step, which is equivalent to a scanning rate of 0.5°/min.
5.2 Calcination Furnace.
5.3 Grinding Equipment, suit
...
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