ASTM D5758-01(2011)e1

Standard Test Method for Determination of Relative Crystallinity of Zeolite ZSM-5 by X-Ray Diffraction

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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Sep-2011
• ICS: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: D32 - Catalysts
• Drafting Committee: D32.05 - Zeolites

Relations

• Replaces: ASTM D5758-01(2007)e1 - Standard Test Method for Determination of Relative Crystallinity of Zeolite ZSM-5 by X-Ray Diffraction
• Effective Date: 01-Oct-2011

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation: D5758 − 01(Reapproved 2011)
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.
ε NOTE—Updated ZSM-5 powder availability footnote editorially in October 2011.
1. Scope 3. Summary of Test Method
3.1 XRD patterns of the sample ZSM-5 and the reference
1.1 This test method covers a procedure for determination
ZSM-5 are obtained under the same conditions. From these
of the relative crystallinity of zeolite ZSM-5 using selected
patterns, there is a choice from two procedures for calculation
peaks from the X-ray diffraction pattern of the zeolite.
of relative crystallinity/ZSM-5.
1.2 The test method provides a number that is the ratio of
3.1.1 Procedure A (Integrated Peak Area Method)—Acom-
intensityofaportionoftheXRDpatternofthesampleZSM-5
parison is made of the sums of intensities (sample versus
to intensity of the corresponding portion of the pattern of a
reference) of the strong peaks, having maxima between about
reference ZSM-5. The intensity ratio, expressed as a
23.1 and 24.3° 2θ.
percentage, is then labeled percent XRD relative crystallinity/
3.1.2 Procedure B (Peak Height Method)—Acomparison is
ZSM-5. This type of comparison is commonly used in zeolite
madeoftheabsolutepeakheights(sampleversusreference)of
technology and is often referred to as percent crystallinity.
the 24.3° 2θ peak.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 4. Significance and Use
responsibility of the user of this standard to establish appro-
4.1 ZSM-5isasiliceouszeolitethatcanbecrystallizedwith
priate safety and health practices and determine the applica-
SiO /Al O ratio in the range of 20 to greater than 1000.
2 2 3
bility of regulatory limitations prior to use.
ZSM-5, upon modification to the H-cation form (HZSM-5) in
a post-crystallization step, has been used since the 1970s as a
2. Referenced Documents
shape selective, acid-site catalyst for petroleum refining and
petrochemicals production, including such processes as
2.1 ASTM Standards:
alkylation, isomerization, fluid cracking catalysis (FCC), and
D3906Test Method for Determination of Relative X-ray
methanol-to-gasoline. The most siliceous member of the
Diffraction Intensities of Faujasite-Type Zeolite-
ZSM-5 family, sometimes called silicalite, is hydrophobic and
Containing Materials
it is used for selective sorption of organic molecules from
D5357Test Method for Determination of Relative Crystal-
water-containing systems.
linity of Zeolite Sodium A by X-ray Diffraction
E177Practice for Use of the Terms Precision and Bias in
4.2 ThisX-rayprocedureisdesignedtoallowareportingof
ASTM Test Methods
the relative degree of crystallization upon manufacture of
E456Terminology Relating to Quality and Statistics
ZSM-5. The relative crystallinity/ZSM-5 number has proven
E691Practice for Conducting an Interlaboratory Study to
useful in technology, research, and specifications.
Determine the Precision of a Test Method
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
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 Oct. 1, 2011. Published December 2011. Originally
ε1
changes in distribution of electron density within the unit cell
approved in 1995. Last previous edition approved in 2007 as D5758–01(2007) .
DOI: 10.1520/D5758-01R11E01. 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 [e-mail]. 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
´1
D5758 − 01 (2011)
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
ovenat105°Cfor2h.Coolthesampleinthehydratorandhold
have a similar history of preparation and composition.
thereatroomtemperatureandabout58%relativehumidityfor
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), then the obtain a pattern of the sample ZSM-5 (in the same day), by
Integrated Peak Area Method (Procedure A) should be used.
scanning over the angle range from 11 to 32° 2θ using
instrument parameters best suited to the
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