ASTM_D_4365_-_19.pdf

Designation:D436519Standard Test Method forDetermining Micropore Volume and Zeolite Area of aCatalyst1This standard is issued under the fixed designation D4365;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 totalsurface area and mesopore area.From these results are calcu-lated the zeolite area and micropore volume of a zeolitecontaining catalyst.The micropore volume is related to thepercent zeolite in the catalyst.The zeolite area,a numberrelated to the surface area within the zeolite pores,may also becalculated.Zeolite area,however,is difficult to interpret inphysical terms because of the manner in which nitrogenmolecules pack within the zeolite.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For a specific precautionary statement,see Note 3.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D3663 Test Method for Surface Area of Catalysts andCatalyst CarriersD3906 Test Method for Determination of Relative X-rayDiffractionIntensitiesofFaujasite-TypeZeolite-Containing MaterialsE177 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.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 micropore volume of the catalyst,nthe pore volumein pores having radii less than 1 nm,usually associated with thezeolite portion of the catalyst,and determined from theintercept of the t-plot.3.1.2 surface area of a catalyst,nthe total surface of thecatalyst obtained from the BET method.3.1.2.1 DiscussionSurface area may be used interchange-ably with BET area.It is expressed in square meters per gram.3.1.3 t-area of the catalyst,nthe area determined from theslope of the t-plot.3.1.3.1 Discussiont-area may be used interchangeablywith matrix area or external surface area.It is expressed insquare meters per gram.3.1.4 zeolite area of a catalyst,nthe difference betweentotal surface area and mesopore area.3.1.4.1 DiscussionThe zeolite area may be used inter-changeably with micropore area.It is expressed in squaremeters per gram.3.2 Symbols:PH1=initial helium pressure,torrPH2=helium pressure after equilibration,torrSB=slope of BET plot,11.7IB=intercept of BET plot,11.7AB=BET area,11.9N=Avogadros numberACS=Cross-sectional area of adsorbed nitrogen mol-eculeSt=slope of t-plot,11.13It=intercept of t-plot,11.13At=t-area1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct responsibility of Subcommittee D32.01 on Physical-Chemical Properties.Current edition approved July 1,2019.Published July 2019.Originally approvedin 1984.Last previous edition approved in 2013 as D4365 13.DOI:10.1520/D4365-19.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 TH1=temperature of manifold at initial helium pressure,CTH2=temperature of manifold after equilibration,CTx(i)=extra volume bulb temperature,CTx(i)=extra volume bulb temperature,KP1(i)=initial N2pressure,torrT1(i)=manifold temperature at initial N2pressure,KT1(i)=manifold temperature at initial N2pressure,CP2(i)=pressure after equilibration,torrT2(i)=manifold temperature after equilibration,KT2(i)=manifold temperature after equilibration,CP0(i)=liquid nitrogen vapor pressure,torrTs(i)=liquid nitrogen temperature,KPc=nitrogen critical pressureTc=nitrogen critical temperatureX=relative pressure,P2/P0Vd=volume of manifold,c