ASTM D5758-01(2021)
(Test Method)Standard Test Method for Determination of Relative Crystallinity of Zeolite ZSM-5 by X-Ray Diffraction
Standard Test Method for Determination of Relative Crystallinity of Zeolite ZSM-5 by X-Ray Diffraction
SIGNIFICANCE AND USE
4.1 ZSM-5 is a siliceous zeolite that can be crystallized with SiO2/Al2O3 ratio in the range of 20 to greater than 1000. ZSM-5, upon modification to the H-cation form (HZSM-5) in a post-crystallization step, has been used since the 1970s as a shape selective, acid-site catalyst for petroleum refining and petrochemicals production, including such processes as alkylation, isomerization, fluid cracking catalysis (FCC), and methanol-to-gasoline. The most siliceous member of the ZSM-5 family, sometimes called silicalite, is hydrophobic and it is used for selective sorption of organic molecules from water-containing systems.
4.2 This X-ray procedure is designed to allow a reporting of the relative degree of crystallization upon manufacture of ZSM-5. The relative crystallinity/ZSM-5 number has proven useful in technology, research, and specifications.
4.3 The Integrated Peak Area Method (Procedure A) is preferred over the Peak Height Method (Procedure B) since it calculates XRD intensity as a sum from several peaks rather than utilizing just one peak. Drastic changes in intensity of individual peaks in the XRD pattern of ZSM-5 can result from changes in distribution of electron density within the unit cell of the ZSM-5 zeolite. The electron density distribution is dependent upon the following factors:
4.3.1 Extent of filling of pores with guest molecules and the nature of these guest molecules.
4.3.2 Type of cations and extent of their presence (these cations may also affect the absorption of X rays by the ZSM-5 sample).
4.3.3 In this XRD method, the guest molecule H2O completes the filling of the pores. Other guest molecule types may also be present, including one of numerous amines, diamines, and quarternary ammonium cations that can function as a template for crystallization of the ZSM-5 structure.
4.3.4 Because of the factors mentioned in 4.3.1 to 4.3.3 that could vary the intensities of the XRD peaks in ZSM-5, this XRD method will provide the best de...
SCOPE
1.1 This test method covers a procedure for determination of the relative crystallinity of zeolite ZSM-5 using selected peaks from the X-ray diffraction pattern of the zeolite.
1.2 The test method provides a number that is the ratio of intensity of a portion of the XRD pattern of the sample ZSM-5 to intensity of the corresponding portion of the pattern of a reference ZSM-5. The intensity ratio, expressed as a percentage, is then labeled percent XRD relative crystallinity/ZSM-5. This type of comparison is commonly used in zeolite technology and is often referred to as percent crystallinity.
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
Relations
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: D5758 − 01 (Reapproved 2021)
Standard Test Method for
Determination of Relative Crystallinity of Zeolite ZSM-5 by
X-Ray Diffraction
This standard is issued under the fixed designation D5758; 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 E691Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 This test method covers a procedure for determination
of the relative crystallinity of zeolite ZSM-5 using selected
3. Summary of Test Method
peaks from the X-ray diffraction pattern of the zeolite.
3.1 XRD patterns of the sample ZSM-5 and the reference
1.2 The test method provides a number that is the ratio of
ZSM-5 are obtained under the same conditions. From these
intensity of a portion of the XRD pattern of the sample ZSM-5
patterns, there is a choice from two procedures for calculation
to intensity of the corresponding portion of the pattern of a
of relative crystallinity/ZSM-5.
reference ZSM-5. The intensity ratio, expressed as a
3.1.1 Procedure A (Integrated Peak Area Method)—Acom-
percentage, is then labeled percent XRD relative crystallinity/
parison is made of the sums of intensities (sample versus
ZSM-5. This type of comparison is commonly used in zeolite
reference) of the strong peaks, having maxima between about
technology and is often referred to as percent crystallinity.
23.1 and 24.3° 2θ.
1.3 This standard does not purport to address all of the
3.1.2 Procedure B (Peak Height Method)—Acomparison is
safety concerns, if any, associated with its use. It is the
madeoftheabsolutepeakheights(sampleversusreference)of
responsibility of the user of this standard to establish appro-
the 24.3° 2θ peak.
priate safety, health, and environmental practices and deter-
4. Significance and Use
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
4.1 ZSM-5isasiliceouszeolitethatcanbecrystallizedwith
dance with internationally recognized principles on standard-
SiO /Al O ratio in the range of 20 to greater than 1000.
2 2 3
ization established in the Decision on Principles for the
ZSM-5, upon modification to the H-cation form (HZSM-5) in
Development of International Standards, Guides and Recom-
a post-crystallization step, has been used since the 1970s as a
mendations issued by the World Trade Organization Technical
shape selective, acid-site catalyst for petroleum refining and
Barriers to Trade (TBT) Committee.
petrochemicals production, including such processes as
alkylation, isomerization, fluid cracking catalysis (FCC), and
2. Referenced Documents
methanol-to-gasoline. The most siliceous member of the
2.1 ASTM Standards:
ZSM-5 family, sometimes called silicalite, is hydrophobic and
D3906Test Method for Determination of Relative X-ray
it is used for selective sorption of organic molecules from
Diffraction Intensities of Faujasite-Type Zeolite-
water-containing systems.
Containing Materials
4.2 ThisX-rayprocedureisdesignedtoallowareportingof
D5357Test Method for Determination of Relative Crystal-
the relative degree of crystallization upon manufacture of
linity of Zeolite Sodium A by X-ray Diffraction
ZSM-5. The relative crystallinity/ZSM-5 number has proven
E177Practice for Use of the Terms Precision and Bias in
useful in technology, research, and specifications.
ASTM Test Methods
4.3 The Integrated Peak Area Method (Procedure A) is
E456Terminology Relating to Quality and Statistics
preferred over the Peak Height Method (Procedure B) since it
calculates XRD intensity as a sum from several peaks rather
This test method is under the jurisdiction of ASTM Committee D32 on
than utilizing just one peak. Drastic changes in intensity of
Catalysts and is the direct responsibility of Subcommittee D32.05 on Zeolites.
individual peaks in the XRD pattern of ZSM-5 can result from
Current edition approved June 1, 2021. Published June 2021. Originally
changes in distribution of electron density within the unit cell
approved in 1995. Last previous edition approved in 2015 as D5758–01(2015).
DOI: 10.1520/D5758-01R21.
of the ZSM-5 zeolite. The electron density distribution is
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dependent upon the following factors:
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
4.3.1 Extentoffillingofporeswithguestmoleculesandthe
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. nature of these guest molecules.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5758 − 01 (2021)
FIG. 1 X-Ray Diffraction Wide Scan Pattern of Zeolite ZSM-5—ASTM Z-20 (Reference)
NOTE 1—The planimeter will not be needed if the XRD instrument is
4.3.2 Type of cations and extent of their presence (these
equipped with computerized data acquisition and reduction capability.
cations may also affect the absorption of X rays by the ZSM-5
sample).
6. Reagents and Materials
4.3.3 In this XRD method, the guest molecule H O com-
6.1 ZSM-5 Powder, as reference standard, preferably with
pletes the filling of the pores. Other guest molecule types may
a mean particle diameter of less than 10 µm.
also be present, including one of numerous amines, diamines,
and quarternary ammonium cations that can function as a
7. Procedure
template for crystallization of the ZSM-5 structure.
7.1 Carry out steps 7.2 through 7.4, in an identical manner,
4.3.4 Because of the factors mentioned in 4.3.1 to 4.3.3 that
for both the sample ZSM-5 and the reference ZSM-5.
could vary the intensities of the XRD peaks in ZSM-5, this
XRD method will provide the best determination of relative
7.2 Place about 1.5 g of finely divided ZSM-5 in the drying
crystallinity when the reference ZSM-5 and sample ZSM-5
oven at 105°C for 2 h. Cool the sample in the hydrator and
have a similar history of preparation and composition.
hold there at room temperature and about 58% relative
humidity for at least 16 h.
4.4 ZSM-5 can exist with either orthorhombic or mono-
clinic symmetry, depending upon the composition of the
NOTE 2—Grinding of course-textured samples should be done gently.
precursorgelorpost-crystallizationmodificationconditions,or
Overgrinding can lead to breaking up of fine crystals and destruction of
the zeolite.
both. In the orthorhombic type, the XRD peaks centered at
NOTE 3—Drying, followed by rehydration, results in filling the zeolite
about23.1and23.8°2θareusuallysplitintodoublets,whereas
pores with water of hydration but without an excess of moisture residing
thelesssymmetricmonoclinictypemayshowafurthersplitof
on the surface of the zeolite particles.
these peaks into triplets. The peak area intensities of these
7.3 Pack the humidity-conditioned sample into an XRD
peaks are unaffected by the crystalline form.The XRD peak at
sample holder.
24.3°2θfortheorthorhombicformisasingletandhenceisthe
mostsuitableforthePeakHeightMethod(ProcedureB).Ifthe
7.4 ObtainanXRDpatternofthereferenceZSM-5andalso
24.3° peak is split (doublet in the monoclinic form), t
...
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