1、Designation:D366320Standard Test Method forSurface Area of Catalysts and Catalyst Carriers1This standard is issued under the fixed designation D3663;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number i
2、n 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 surfaceareas of catalyst and catalyst carriers that have Type II or IVnitrogen adsorption isotherms,an
3、d at least 1 m2/g of area.Avolumetric measuring system is used to obtain at least four datapoints which fit on the linear BET2equation line.1.2 UnitsThe values stated in SI units are to be regardedas standard.The values given in parentheses after SI units areprovided for information only and are not
4、 considered standard.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 limitati
5、ons prior to use.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 Tech
6、nicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3D3766 Terminology Relating to Catalysts and CatalysisE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaborat
7、ory Study toDetermine the Precision of a Test Method3.Terminology3.1 Consult Terminology D3766 for definitions of otherterms used.3.2 Definitions:3.2.1 surface area of a catalyst,nthe total probe acces-sible surface of the catalyst;it is expressed in square metres pergram.3.3 Symbols:PH1=initial hel
8、ium pressure,torrPH2=helium pressure after equilibration,torrTH1=temperature of manifold at initial helium pressure,CTH2=temperature of manifold after equilibration,CP1=initial N2pressure,torrT1=manifold temperature at initial N2pressure,KT1=manifold temperature at initial N2pressure,CP2=pressure af
9、ter equilibration,torrP0=liquid nitrogen vapor pressure,torrTs=liquid nitrogen temperature,KX=relative pressure,P2/P0Vd=volume of manifold,cm3Vx=extra volume bulb,cm3Vs=dead-space volume,cm3Ws=mass of sample,gW1=tare mass of sample tube,gW2=sample+tare mass of tube,gVds=volume of nitrogen in the dea
10、d-space,cm3V1=see 10.4.4V2=see 10.4.6Vt=see 10.4.7Va=see 10.4.9Vm=see 10.8T1x=initial extra-volume bulb temperature,KT1 x(i)=initial extra-volume bulb temperature,CT2 x=extra-volume bulb temperature after equilibrium,KT2 x(i)=extra-volume bulb temperature after equilibrium,C4.Summary of Test Method4
11、.1 The surface area of a catalyst or catalyst carrier isdetermined by measuring the amount of nitrogen gas adsorbedat various low-pressure levels by the catalyst sample.Pressuredifferentials caused by introducing the catalyst surface area toa fixed volume of nitrogen in the test apparatus are measur
12、edand used to calculate BET surface area.1This 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 Oct.1,2020.Published November 2020.Originallyapproved in 1978.Last p
13、revious edition approved in 2015 as D3663 03(2015).DOI:10.1520/D3663-20.2Brunauer,Emmett,Teller,Journal of American Chemical Society,JACS,No.60,1938,p.309.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStan
14、dards 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 s
15、tandardization 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.15.Apparatus45.1 Aschematic diagram of a suitable apparatus is shown inFig.1.It may be co
16、nstructed of glass or of metal.Commercialmetal instruments are available.It has the following features:5.1.1 Distribution Manifold,having a volume between 20and 35 cm3,(Vd),known to the nearest 0.05 cm3.This volumeis defined as the volume between the stopcocks or valves andincludes the pressure gauge.5.1.2 Vacuum System,capable of attaining pressures below104torr(1 torr=133.3 Pa).This can include a vacuum gauge(not shown in Fig.1).Access to the distribution manifold isthrough the valve V.5.1.3 P