ASTM_D_3906_-_03_2013.pdf

Designation:D390603(Reapproved 2013)Standard Test Method forDetermination of Relative X-ray Diffraction Intensities ofFaujasite-Type Zeolite-Containing Materials1This standard is issued under the fixed designation D3906;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of relativeX-ray diffraction intensities of zeolites having the faujasitecrystal structure,including synthetic Y and X zeolites,theirmodifications such as the various cation exchange forms,andthe dealuminized,decationated,and ultrastable forms of Y.These zeolites have cubic symmetry with a unit cell parameterusually within the limits of 24.2 and 25.0 (2.42 and 2.50nm).1.2 The samples include zeolite preparations in the variousforms,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 ofcounts under the peak or the product of the peak height and thepeak width.1.4 This test method provides a number that is the ratio ofintensity of portions of the XRD pattern of the sample tointensity of the corresponding portion of the pattern of areference zeolite,NaY.(Laboratories may use a modified Y orX,for example,REY as a secondary standard.)The intensityratio,expressed as a percentage,is then labeled“%XRDintensity/NaY.”1.5 Under certain conditions such a ratio is the percentzeolite in the sample.These conditions include:1.5.1 The zeolite in the sample is the same as the referencezeolite.1.5.2 The absorption for the X-rays used is the same for thezeolite and the nonzeolite portions of the sample.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Summary of Test Method3.1 The XRD patterns of the zeolite containing sample andthe reference sample(NaY),are obtained under the sameconditions.If the XRD pattern of the zeolite is sufficientlystrong,a comparison of intensities of eight peaks is used togive%XRD intensity/NaY.For lower zeolite content intensi-ties of the(533)peak(23.5 with Cu K radiation)arecompared to provide“%XRD intensity/NaY(533).”4.Significance and Use4.1 Zeolites Y and X,particularly for catalyst and adsorbentapplications,are a major article of manufacture and commerce.Catalysts and adsorbents comprising these zeolites in variousforms plus binder and other components have likewise becomeimportant.Y-based catalysts are used for fluid catalytic crack-ing(FCC)and hydrocracking of petroleum,while X-basedadsorbents are used for desiccation,sulfur compound removal,and air separation.4.2 This X-ray procedure is designed to monitor these Y andX zeolites and catalysts and adsorbents,providing a numbermore or less closely related to percent zeolite in the sample.This number has proven useful in technology,research,andspecifications.4.3 Drastic changes in intensity of individual peaks in theXRD patterns of Y and X can result from changes of distribu-tion of electron density within the unit cell of the zeolite.Theelectron density distribution is dependent upon the extent offilling of pores in the zeolite with guest molecules,and on thenature of the guest molecules.In this XRD method,the guest1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct responsibility of Subcommittee D32.05 on Zeolites.Current edition approved Dec.1,2013.Published December 2013.Originallyapproved in 1980.Last previous edition approved in 2008 as D3906 03(2008).DOI:10.1520/D3906-03R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 molecule H2O completely fills the pores.Intensity changesmay also result if some or all of the cations in Y and X areexchanged by other cations.4.3.1 Because of the factors mentioned in 4.3 that couldvary the intensities of the XRD peaks,this XRD method willprovide the best determination of relative crystallinity when thereference and sample have a similar history of preparation andcomposition.4.4 Corrections are possible that can make this