ASTM D3906-19
(Test Method)Standard Test Method for Determination of Relative X-ray Diffraction Intensities of Faujasite-Type Zeolite-Containing Materials
Standard Test Method for Determination of Relative X-ray Diffraction Intensities of Faujasite-Type Zeolite-Containing Materials
SIGNIFICANCE AND USE
4.1 Zeolites Y and X, particularly for catalyst and adsorbent applications, are a major article of manufacture and commerce. Catalysts and adsorbents comprising these zeolites in various forms plus binder and other components have likewise become important. Y-based catalysts are used for fluid catalytic cracking (FCC) and hydrocracking of petroleum, while X-based adsorbents are used for desiccation, sulfur compound removal, and air separation.
4.2 This X-ray procedure is designed to monitor these Y and X zeolites and catalysts and adsorbents, providing a number more or less closely related to percent zeolite in the sample. This number has proven useful in technology, research, and specifications.
4.3 Drastic changes in intensity of individual peaks in the XRD patterns of Y and X can result from changes of distribution of electron density within the unit cell of the zeolite. The electron density distribution is dependent upon the extent of filling of pores in the zeolite with guest molecules, and on the nature of the guest molecules. In this XRD method, the guest molecule H2O completely fills the pores. Intensity changes may also result if some or all of the cations in Y and X are exchanged by other cations.
4.3.1 Because of the factors mentioned in 4.3 that could vary the intensities of the XRD peaks, this XRD method will provide the best determination of relative crystallinity when the reference and sample have a similar history of preparation and composition.
4.4 Corrections are possible that can make this XRD method accurate for measuring percent zeolite in many specific situations. These corrections are well known to those skilled in X-ray diffraction. It is not practical to specify those corrections here.
SCOPE
1.1 This test method covers the determination of relative X-ray diffraction intensities of zeolites having the faujasite crystal structure, including synthetic Y and X zeolites, their modifications such as the various cation exchange forms, and the dealuminized, decationated, and ultrastable forms of Y. These zeolites have cubic symmetry with a unit cell parameter usually within the limits of 24.2 and 25.0 Å (2.42 and 2.50 nm).
1.2 The samples include zeolite preparations in the various forms, and catalysts and adsorbents containing these zeolites.
1.3 The term “intensity of an X-ray powder diffraction (XRD) peak” is the “integral intensity,” either the area of counts under the peak or the product of the peak height and the peak width.
1.4 This test method provides a number that is the ratio of intensity of portions of the XRD pattern of the sample to intensity of the corresponding portion of the pattern of a reference zeolite, NaY. (Laboratories may use a modified Y or X, for example, REY as a secondary standard.) The intensity ratio, expressed as a percentage, is then labeled “% XRD intensity/NaY.”
1.5 Under certain conditions such a ratio is the percent zeolite in the sample. These conditions include:
1.5.1 The zeolite in the sample is the same as the reference zeolite.
1.5.2 The absorption for the X-rays used is the same for the zeolite and the nonzeolite portions of the sample.
1.6 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.
1.7 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
- 31-Mar-2019
- Technical Committee
- D32 - Catalysts
- Drafting Committee
- D32.05 - Zeolites
Relations
- Effective Date
- 01-Apr-2019
- Effective Date
- 01-Apr-2022
- Effective Date
- 01-Oct-2017
- Effective Date
- 01-Oct-2017
- Effective Date
- 01-May-2014
- Effective Date
- 15-Nov-2013
- Effective Date
- 15-Nov-2013
- Effective Date
- 15-Nov-2013
- Effective Date
- 15-Nov-2013
- Effective Date
- 15-Aug-2013
- Effective Date
- 01-May-2013
- Effective Date
- 01-May-2013
- Effective Date
- 01-May-2012
- Effective Date
- 01-May-2012
- Effective Date
- 01-Nov-2011
Overview
ASTM D3906-19 is the standard test method for determining the relative X-ray diffraction (XRD) intensities of faujasite-type zeolite-containing materials. This method applies specifically to zeolites with the faujasite crystal structure, including both synthetic Y and X zeolites as well as their modified forms, such as cation-exchanged, dealuminized, decationated, and ultrastable types. The test is an essential tool for industries involved in the manufacture and application of zeolite-based catalysts and adsorbents, providing key insights into the relative zeolite content of materials.
The primary objective of this ASTM standard is to establish a reliable procedure for comparing the XRD patterns of a zeolite-containing sample to a defined reference (typically NaY zeolite). By expressing the intensity ratio as “% XRD intensity/NaY,” users can monitor changes in zeolite composition critical to research, quality control, and industrial processes.
Key Topics
- X-ray Diffraction Analysis: The method uses XRD patterns to compare the relative intensity of specific peaks for both sample and reference materials.
- Application to Y and X Zeolites: Focused on materials with cubic symmetry and unit cell parameters between 24.2 and 25.0 Å.
- Reference Standards: NaY is the primary reference material, although modified forms such as REY can be used, depending on the laboratory setup.
- Measurement Techniques:
- Integral intensity of a diffraction peak, measured either by area under the curve or by the product of peak height and width.
- Use of modern digital integration or planimeter methods for accurate data analysis.
- Interpretation of Results:
- The derived ratio provides an indicator closely related to the percent zeolite in the sample under certain controlled conditions.
- Factors such as cation exchange, guest molecule occupation, and unit cell variations can influence peak intensities and must be considered in interpretation.
Applications
The ASTM D3906-19 test method is foundational in several high-value industrial processes:
- Catalyst Manufacturing: Used extensively to monitor the quality and composition of Y-based catalysts for fluid catalytic cracking (FCC) and hydrocracking in petroleum refining.
- Adsorbent Production: Essential for verifying the presence and state of X-based zeolites in products designed for desiccation, sulfur removal, and air separation.
- Research and Development: Valuable in developing new zeolite-based materials and monitoring modifications such as cation exchange or dealumination.
- Quality Control and Specifications: Provides a standardized approach to ensure consistency across batches of zeolite-containing catalysts and adsorbents.
Related Standards
When implementing or interpreting ASTM D3906-19, consider the following related ASTM standards to ensure comprehensive quality and statistical control:
- ASTM E177: Practice for Use of the Terms Precision and Bias in ASTM Test Methods
- ASTM E456: Terminology Relating to Quality and Statistics
- ASTM E691: Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
Practical Value
Using ASTM D3906-19 ensures reliable, reproducible assessment of the relative crystallinity and zeolite content in complex materials-a critical need for industries relying on the unique catalytic and adsorptive properties of faujasite-type zeolites. By standardizing XRD analysis and comparison methods, organizations can improve material performance, meet specification requirements, and maintain compliance with international best practices.
Keywords: ASTM D3906-19, X-ray diffraction, faujasite-type zeolite, zeolite Y, zeolite X, catalyst, adsorbent, crystallinity, quality control, NaY reference, industrial standards.
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Frequently Asked Questions
ASTM D3906-19 is a standard published by ASTM International. Its full title is "Standard Test Method for Determination of Relative X-ray Diffraction Intensities of Faujasite-Type Zeolite-Containing Materials". This standard covers: SIGNIFICANCE AND USE 4.1 Zeolites Y and X, particularly for catalyst and adsorbent applications, are a major article of manufacture and commerce. Catalysts and adsorbents comprising these zeolites in various forms plus binder and other components have likewise become important. Y-based catalysts are used for fluid catalytic cracking (FCC) and hydrocracking of petroleum, while X-based adsorbents are used for desiccation, sulfur compound removal, and air separation. 4.2 This X-ray procedure is designed to monitor these Y and X zeolites and catalysts and adsorbents, providing a number more or less closely related to percent zeolite in the sample. This number has proven useful in technology, research, and specifications. 4.3 Drastic changes in intensity of individual peaks in the XRD patterns of Y and X can result from changes of distribution of electron density within the unit cell of the zeolite. The electron density distribution is dependent upon the extent of filling of pores in the zeolite with guest molecules, and on the nature of the guest molecules. In this XRD method, the guest molecule H2O completely fills the pores. Intensity changes may also result if some or all of the cations in Y and X are exchanged by other cations. 4.3.1 Because of the factors mentioned in 4.3 that could vary the intensities of the XRD peaks, this XRD method will provide the best determination of relative crystallinity when the reference and sample have a similar history of preparation and composition. 4.4 Corrections are possible that can make this XRD method accurate for measuring percent zeolite in many specific situations. These corrections are well known to those skilled in X-ray diffraction. It is not practical to specify those corrections here. SCOPE 1.1 This test method covers the determination of relative X-ray diffraction intensities of zeolites having the faujasite crystal structure, including synthetic Y and X zeolites, their modifications such as the various cation exchange forms, and the dealuminized, decationated, and ultrastable forms of Y. These zeolites have cubic symmetry with a unit cell parameter usually within the limits of 24.2 and 25.0 Å (2.42 and 2.50 nm). 1.2 The samples include zeolite preparations in the various forms, and catalysts and adsorbents containing these zeolites. 1.3 The term “intensity of an X-ray powder diffraction (XRD) peak” is the “integral intensity,” either the area of counts under the peak or the product of the peak height and the peak width. 1.4 This test method provides a number that is the ratio of intensity of portions of the XRD pattern of the sample to intensity of the corresponding portion of the pattern of a reference zeolite, NaY. (Laboratories may use a modified Y or X, for example, REY as a secondary standard.) The intensity ratio, expressed as a percentage, is then labeled “% XRD intensity/NaY.” 1.5 Under certain conditions such a ratio is the percent zeolite in the sample. These conditions include: 1.5.1 The zeolite in the sample is the same as the reference zeolite. 1.5.2 The absorption for the X-rays used is the same for the zeolite and the nonzeolite portions of the sample. 1.6 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. 1.7 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 Zeolites Y and X, particularly for catalyst and adsorbent applications, are a major article of manufacture and commerce. Catalysts and adsorbents comprising these zeolites in various forms plus binder and other components have likewise become important. Y-based catalysts are used for fluid catalytic cracking (FCC) and hydrocracking of petroleum, while X-based adsorbents are used for desiccation, sulfur compound removal, and air separation. 4.2 This X-ray procedure is designed to monitor these Y and X zeolites and catalysts and adsorbents, providing a number more or less closely related to percent zeolite in the sample. This number has proven useful in technology, research, and specifications. 4.3 Drastic changes in intensity of individual peaks in the XRD patterns of Y and X can result from changes of distribution of electron density within the unit cell of the zeolite. The electron density distribution is dependent upon the extent of filling of pores in the zeolite with guest molecules, and on the nature of the guest molecules. In this XRD method, the guest molecule H2O completely fills the pores. Intensity changes may also result if some or all of the cations in Y and X are exchanged by other cations. 4.3.1 Because of the factors mentioned in 4.3 that could vary the intensities of the XRD peaks, this XRD method will provide the best determination of relative crystallinity when the reference and sample have a similar history of preparation and composition. 4.4 Corrections are possible that can make this XRD method accurate for measuring percent zeolite in many specific situations. These corrections are well known to those skilled in X-ray diffraction. It is not practical to specify those corrections here. SCOPE 1.1 This test method covers the determination of relative X-ray diffraction intensities of zeolites having the faujasite crystal structure, including synthetic Y and X zeolites, their modifications such as the various cation exchange forms, and the dealuminized, decationated, and ultrastable forms of Y. These zeolites have cubic symmetry with a unit cell parameter usually within the limits of 24.2 and 25.0 Å (2.42 and 2.50 nm). 1.2 The samples include zeolite preparations in the various forms, and catalysts and adsorbents containing these zeolites. 1.3 The term “intensity of an X-ray powder diffraction (XRD) peak” is the “integral intensity,” either the area of counts under the peak or the product of the peak height and the peak width. 1.4 This test method provides a number that is the ratio of intensity of portions of the XRD pattern of the sample to intensity of the corresponding portion of the pattern of a reference zeolite, NaY. (Laboratories may use a modified Y or X, for example, REY as a secondary standard.) The intensity ratio, expressed as a percentage, is then labeled “% XRD intensity/NaY.” 1.5 Under certain conditions such a ratio is the percent zeolite in the sample. These conditions include: 1.5.1 The zeolite in the sample is the same as the reference zeolite. 1.5.2 The absorption for the X-rays used is the same for the zeolite and the nonzeolite portions of the sample. 1.6 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. 1.7 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 D3906-19 is classified under the following ICS (International Classification for Standards) categories: 71.060.01 - Inorganic chemicals in general. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM D3906-19 has the following relationships with other standards: It is inter standard links to ASTM D3906-03(2013), ASTM E456-13a(2022)e1, ASTM E456-13A(2017)e3, ASTM E456-13A(2017)e1, ASTM E177-14, ASTM E456-13ae3, ASTM E456-13a, ASTM E456-13ae2, ASTM E456-13ae1, ASTM E456-13, ASTM E691-13, ASTM E177-13, ASTM E456-12e1, ASTM E456-12, ASTM E691-11. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ASTM D3906-19 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: D3906 − 19
Standard Test Method for
Determination of Relative X-ray Diffraction Intensities of
Faujasite-Type Zeolite-Containing Materials
This standard is issued under the fixed designation D3906; 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 ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This test method covers the determination of relative
mendations issued by the World Trade Organization Technical
X-ray diffraction intensities of zeolites having the faujasite
Barriers to Trade (TBT) Committee.
crystal structure, including synthetic Y and X zeolites, their
modifications such as the various cation exchange forms, and
2. Referenced Documents
the dealuminized, decationated, and ultrastable forms of Y.
These zeolites have cubic symmetry with a unit cell parameter 2.1 ASTM Standards:
usually within the limits of 24.2 and 25.0 Å (2.42 and E177 Practice for Use of the Terms Precision and Bias in
2.50 nm). ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
1.2 The samples include zeolite preparations in the various
E691 Practice for Conducting an Interlaboratory Study to
forms, and catalysts and adsorbents containing these zeolites.
Determine the Precision of a Test Method
1.3 The term “intensity of an X-ray powder diffraction
(XRD) peak” is the “integral intensity,” either the area of
3. Summary of Test Method
counts under the peak or the product of the peak height and the
3.1 The XRD patterns of the zeolite containing sample and
peak width.
the reference sample (NaY) are obtained under the same
1.4 This test method provides a number that is the ratio of
conditions. If the XRD pattern of the zeolite is sufficiently
intensity of portions of the XRD pattern of the sample to
strong, a comparison of intensities of eight peaks is used to
intensity of the corresponding portion of the pattern of a
give % XRD intensity/NaY. For lower zeolite content intensi-
reference zeolite, NaY. (Laboratories may use a modified Y or
ties of the (533) peak (23.5° with Cu Kα radiation) are
X, for example, REY as a secondary standard.) The intensity
compared to provide “% XRD intensity/NaY (533).”
ratio, expressed as a percentage, is then labeled “% XRD
intensity/NaY.”
4. Significance and Use
1.5 Under certain conditions such a ratio is the percent
4.1 Zeolites Y and X, particularly for catalyst and adsorbent
zeolite in the sample. These conditions include:
applications, are a major article of manufacture and commerce.
1.5.1 The zeolite in the sample is the same as the reference
Catalysts and adsorbents comprising these zeolites in various
zeolite.
forms plus binder and other components have likewise become
1.5.2 The absorption for the X-rays used is the same for the
important. Y-based catalysts are used for fluid catalytic crack-
zeolite and the nonzeolite portions of the sample.
ing (FCC) and hydrocracking of petroleum, while X-based
1.6 This standard does not purport to address all of the adsorbents are used for desiccation, sulfur compound removal,
safety concerns, if any, associated with its use. It is the and air separation.
responsibility of the user of this standard to establish appro-
4.2 This X-ray procedure is designed to monitor these Y and
priate safety, health, and environmental practices and deter-
X zeolites and catalysts and adsorbents, providing a number
mine the applicability of regulatory limitations prior to use.
more or less closely related to percent zeolite in the sample.
1.7 This international standard was developed in accor-
This number has proven useful in technology, research, and
dance with internationally recognized principles on standard-
specifications.
This test method is under the jurisdiction of ASTM Committee D32 on
Catalysts and is the direct responsibility of Subcommittee D32.05 on Zeolites. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2019. Published April 2019. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1980. Last previous edition approved in 2013 as D3906 – 03(2013). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D3906-19. theASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3906 − 19
4.3 Drastic changes in intensity of individual peaks in the situations.These corrections are well known to those skilled in
XRD patterns of Y and X can result from changes of distribu- X-ray diffraction. It is not practical to specify those corrections
tion of electron density within the unit cell of the zeolite. The here.
electron density distribution is dependent upon the extent of
filling of pores in the zeolite with guest molecules, and on the 5. Apparatus
nature of the guest molecules. In this XRD method, the guest
5.1 X-ray Diffractometer, equipped with a strip chart re-
molecule H O completely fills the pores. Intensity changes
corder or with computerized data acquisition and reduction
may also result if some or all of the cations in Y and X are
capability, using copper K-alpha radiation.
exchanged by other cations.
5.2 Drying Oven, set at 110 °C.
4.3.1 Because of the factors mentioned in 4.3 that could
vary the intensities of the XRD peaks, this XRD method will 5.3 Hydrator (Glass Laboratory Desiccator), maintained at
providethebestdeterminationofrelativecrystallinitywhenthe 35 % relative humidity by a saturated solution of salt, such as
reference and sample have a similar history of preparation and CaCl ·6H O.
2 2
composition.
5.4 Planimeter or Appropriate Peak Profile Analysis or
4.4 Corrections are possible that can make this XRD Digital Integration Software, if XRD is not equipped with
methodaccurateformeasuringpercentzeoliteinmanyspecific appropriate software data analysis capability.
Angle (°2θ)
FIG. 1 X-Ray Diffraction Patterns of ASTM Zeolite Samples Upper—NaY; Lower—Cracking Catalyst Intensity
D3906 − 19
Angle (°2θ)
FIG. 2 NaY—Complete Diffractometer Scan Intensity
NOTE 1—Modern analysis software performs either numerical integra-
reasonable peak heights. If possible the height of the (533)
tionorpeakmodellingbyprofilefitting,orboth.Usingthesemethodstrue
peak for the sample should be at least 10 % of full scale. Fig.
peak areas values can be obtained too.
1 shows such patterns for the reference NaY and for a
zeolite-containing catalyst.
6. Reagents and Materials
8.5 If this first pattern of the sample contains XRD peaks of
6.1 NaY Powder and RE Exchanged Y Powder, as reference
some nonfaujasite components, it must be established whether
standards.
this may cause interference in the following steps. (Fig. 2 is a
7. Sampling
complete diffractometer scan for NaY.)
7.1 Conduct sampling by splitting a large portion of the
8.6 Obtain a second XRD pattern by scanning over a small
sample and reference material homogeneously. 1
angle range at ⁄4 °/min.
7.2 Divide the sample and reference finely to permit pack-
NOTE4—Longerscantimeswillberequiredforsampleshavingalower
ing of the materials into XRD sample holders.
content of zeolite. For example 0.02º 2θ/step for 1 s may be acceptable for
a pure NaY while 10 to 20 s counting times per step may be required for
NOTE 2—The best test to determine if grinding is required is to try to
a low level of zeolite samples.
packthesampleintheholder.Overgrindingcanleadtobreakingupoffine
crystals and even destruction of zeolite. 8.6.1 The preferred angle range is from 22.5 to 25° 2θ, the
(533)peak.Fig.3showssuchapatternforNaY.Ifinterference
8. Procedure
rules out this range, choose for this step (for both the sample
8.1 Carry out the following steps, 8.2 through 8.5,inan
and the reference patterns) one of the following angle ranges:
identical manner for both the sample and the reference
14.0 to 17.0°, (331) peak
material, NaY.
19.0 to 22.0°, (440) peak
25.5 to 28.0°, (642) peak
8.2 Place about 3 to5gofthe sample in the drying oven at
110 °C for 1 h. Cool the sample in the hydrator and hold at
NOTE 5—These ranges in 8.6 each are of such width that two or more
room temperature and 35 % relative humidity for at least 16 h.
zeolite peaks are included. Such wide ranges are specified to allow for the
variation in peak position over the range of unit cell dimensions 24.2 to
NOTE 3—Drying, followed by rehydration, results in filling the zeolite
25.0 Å (2.42 to 2.50 mm) and to provide a background reading on each
pores with water of hydration but without an excess of moisture residing
sideofthemainpeak.Withineachrangethemajorzeolitepeakwillbethe
on the surface of the zeolite particles.
desired one. See Appendix X1 for peak positions.
8.3 Pack the humidity-conditioned sample into an XRD
sample holder. 9. Calculation
8.4 Obtain a first XRD pattern by scanning over the angle 9.1 Obtain an integral peak intensity for each of the eight
range from 14 to 35° 2θ at about 1°/min and using other
peaks (measured above background) chosen from the patterns
instrument parameters best suited to the diffractometer. from 8.4, for both the sample and reference, in one of three
8.4.1 If a strip chart recorder is used, set the chart drive at
ways:
10 mm⁄min. Select the scale factor (amplification) for the NaY
9.1.1 By approximating the area under the peak as the
reference pattern so that the strong (533) peak at 23.6° is
product of peak height and peak width at half height (use 9.2
between 50 and 100 % of full scale. For the sample the scale
for appropriate area calculations),
factor may be reduced (amplification increased) to provide
9.1.2 By measuring the area under the peak with a planim-
eter (use 9.3 for area by planimeter), or
9.1.3 From the counts recorded by a digital integrating
Available from National Institute of Standards and Technology (NIST), 100
Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov. system (use 9.4 for integrator counts calculation).
D3906 − 19
Angle (°2θ)
FIG. 3 XRD ASTM NaY Intensity
9.2 Approximate Area Calculation: comparison of the sums of peak heights (measured above
9.2.1 Ascale factor correction, SFC, is the ratio
...
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: D3906 − 03 (Reapproved 2013) D3906 − 19
Standard Test Method for
Determination of Relative X-ray Diffraction Intensities of
Faujasite-Type Zeolite-Containing Materials
This standard is issued under the fixed designation D3906; 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 relative XX-ray-ray diffraction intensities of zeolites having the faujasite
crystal structure, including synthetic Y and X zeolites, their modifications such as the various cation exchange forms, and the
dealuminized, decationated, and ultrastable forms of Y. These zeolites have cubic symmetry with a unit cell parameter usually
within the limits of 24.2 and 25.0˚25.0 Å (2.42 and 2.50 nm).2.50 nm).
1.2 The samples include zeolite preparations in the various forms, and catalysts and adsorbents containing these zeolites.
1.3 The term “intensity of an X-ray powder diffraction (XRD) peak” is the “integral intensity,” either the area of counts under
the peak or the product of the peak height and the peak width.
1.4 This test method provides a number that is the ratio of intensity of portions of the XRD pattern of the sample to intensity
of the corresponding portion of the pattern of a reference zeolite, NaY. (Laboratories may use a modified Y or X, for example, REY
as a secondary standard.) The intensity ratio, expressed as a percentage, is then labeled “% XRD intensity/NaY.”
1.5 Under certain conditions such a ratio is the percent zeolite in the sample. These conditions include:
1.5.1 The zeolite in the sample is the same as the reference zeolite.
1.5.2 The absorption for the X-rays used is the same for the zeolite and the nonzeolite portions of the sample.
1.6 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.
This test method is under the jurisdiction of ASTM Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.05 on Zeolites.
Current edition approved Dec. 1, 2013April 1, 2019. Published December 2013April 2019. Originally approved in 1980. Last previous edition approved in 20082013 as
D3906 – 03 (2008).(2013). DOI: 10.1520/D3906-03R13.10.1520/D3906-19.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3906 − 19
1.7 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:
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. Summary of Test Method
3.1 The XRD patterns of the zeolite containing sample and the reference sample (NaY),(NaY) are obtained under the same
conditions. If the XRD pattern of the zeolite is sufficiently strong, a comparison of intensities of eight peaks is used to give % XRD
intensity/NaY. For lower zeolite content intensities of the (533) peak (23.5° with Cu Kα radiation) are compared to provide “%
XRD intensity/NaY (533).”
4. Significance and Use
4.1 Zeolites Y and X, particularly for catalyst and adsorbent applications, are a major article of manufacture and commerce.
Catalysts and adsorbents comprising these zeolites in various forms plus binder and other components have likewise become
important. Y-based catalysts are used for fluid catalytic cracking (FCC) and hydrocracking of petroleum, while X-based adsorbents
are used for desiccation, sulfur compound removal, and air separation.
4.2 This X-ray procedure is designed to monitor these Y and X zeolites and catalysts and adsorbents, providing a number more
or less closely related to percent zeolite in the sample. This number has proven useful in technology, research, and specifications.
4.3 Drastic changes in intensity of individual peaks in the XRD patterns of Y and X can result from changes of distribution of
electron density within the unit cell of the zeolite. The electron density distribution is dependent upon the extent of filling of pores
in the zeolite with guest molecules, and on the nature of the guest molecules. In this XRD method, the guest molecule H O
completely fills the pores. Intensity changes may also result if some or all of the cations in Y and X are exchanged by other cations.
4.3.1 Because of the factors mentioned in 4.3 that could vary the intensities of the XRD peaks, this XRD method will provide
the best determination of relative crystallinity when the reference and sample have a similar history of preparation and
composition.
4.4 Corrections are possible that can make this XRD method accurate for measuring percent zeolite in many specific situations.
These corrections are well known to those skilled in X-ray diffraction. It is not practical to specify those corrections here.
5. Apparatus
5.1 X-ray Diffractometer, equipped with a strip chart recorder or with computerized data acquisition and reduction capability,
using copper K-alpha radiation.
5.2 Drying Oven, set at 110°C.110 °C.
5.3 Hydrator (Glass Laboratory Desiccator), maintained at 35 % relative humidity by a saturated solution of salt, such as
CaCl ·6H O.
2 2
5.4 Planimeter or Appropriate Peak Profile Analysis or Digital Integration Software—Software, Ifif XRD is not equipped with
appropriate software data analysis capability.
NOTE 1—Modern analysis software performs either numerical integration or peak modelling by profile fitting, or both. Using these methods true peak
areas values can be obtained too.
6. Reagents and Materials
6.1 NaY Powder and RE Exchanged Y Powder, as reference standards.
7. Sampling
7.1 Conduct sampling by splitting a large portion of the sample and reference material homogeneously.
7.2 Divide the sample and reference finely to permit packing of the materials into XRD sample holders.
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.
Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 3460,1070, Gaithersburg, MD 20899-3460.20899-1070, http://
www.nist.gov.
D3906 − 19
Angle (°2θ)
FIG. 1 X-Ray Diffraction Patterns of ASTM Zeolite Samples Upper—NaY; Lower—Cracking Catalyst Intensity
Angle (°2θ)
FIG. 2 NaY—Complete Diffractometer Scan Intensity
D3906 − 19
NOTE 2—The best test to determine if grinding is required is to try to pack the sample in the holder. Overgrinding can lead to breaking up of fine crystals
and even destruction of zeolite.
8. Procedure
8.1 Carry out the following steps, 8.2 through 8.5, in an identical manner for both the sample and the reference material, NaY.
8.2 Place about 3 to 5 g of the sample in the drying oven at 110°C110 °C for 1 h. Cool the sample in the hydrator and hold at
room temperature and 35 % relative humidity for at least 16 h.
NOTE 3—Drying, followed by rehydration, results in filling the zeolite pores with water of hydration but without an excess of moisture residing on the
surface of the zeolite particles.
8.3 Pack the humidity-conditioned sample into an XRD sample holder.
8.4 Obtain a first XRD pattern by scanning over the angle range from 14 to 35° 2θ at about 1°/min and using other instrument
parameters best suited to the diffractometer.
8.4.1 If a strip chart recorder is used, set the chart drive at 1010 mm mm/min. ⁄min. Select the scale factor (amplification) for
the NaY reference pattern so that the strong (533) peak at 23.6° is between 50 and 100 % of full scale. For the sample the scale
factor may be reduced (amplification increased) to provide reasonable peak heights. If possible the height of the (533) peak for
the sample should be at least 10 % of full scale. Fig. 1 shows such patterns for the reference NaY and for a zeolite-containing
catalyst.
8.5 If this first pattern of the sample contains XRD peaks of some nonfaujasite components, it must be established whether this
may cause interference in the following steps. (Fig. 2 is a complete diffractometer scan for NaY.)
8.6 Obtain a second XRD pattern by scanning over a small angle range at ⁄4 °⁄min. °/min.
NOTE 4—Longer scan times will be required for samples having a lower content of zeolite. For example 0.02º 2θ/step for 1 s may be acceptable for
a pure NaY while 10 to 20 s counting times per step may be required for a low level of zeolite samples.
8.6.1 The preferred angle range is from 22.5 to 25° 2θ, the (533) peak. Fig. 3 shows such a pattern for NaY. If interference rules
out this range, choose for this step (for both the sample and the reference patterns) one of the following angle ranges:
14.0 to 17.0°, (331) peak
19.0 to 22.0°, (440) peak
25.5 to 28.0°, (642) peak
NOTE 5—These ranges in Step 8.6 each are of such width that two or more zeolite peaks are included. Such wide ranges are specified to allow for the
variation in peak position over the range of unit cell dimensions 24.2 to 25.0 Å (2.42 to 2.50 mm) and to provide a background reading on each side
of the main peak. Within each range the major zeolite peak will be the desired one. See Appendix X1 offor peak positions.
9. Calculation
9.1 Obtain an integral peak intensity for each of the eight peaks (measured above background) chosen from the patterns from
8.4, for both the sample and reference, in one of three ways:
9.1.1 By approximating the area under the peak as the product of peak height and peak width at half height (use 9.2 for
appropriate area calculations), or
9.1.2 By measuring the area under the peak with a planimeter (use 9.3 for area by planimeter), or
9.1.3 From the counts recorded by a digital integrating system (use 9.4 for integrator counts calculation).
9.2 Approximate Area Calculation:
9.2.1 A scale factor correction, SFC, is the ratio of the scale factor used for the sample pattern, SF , to that used for the reference
X
pattern, SF . Thus, SFC = SF /SF . Scale factors are usually expressed in terms of counts per second corresponding to
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