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催化学报 2010
DehydrocyclizationofDiphenylaminetoCarbazoleoverPlatinum-BasedBimetallicCatalysts, PP. 1439-1444 Keywords: diphenylamine,carbazole,dehydrocyclization,platinum,tin,iridium,bimetalliccatalyst Abstract: ？Gasphasedehydrocyclizationofdiphenylamine(DPA)tocarbazoleovermonometallicandbimetallic0.4wt%Pt-basedcatalystsinafixedbedreactorwasstudiedinthepresenceofhydrogenatatemperatureof550oC.AluminaandcarbonsupportedPtcatalystsshowedveryhighinitialactivity(>95%).TheselectivityforcarbazoleovercarbonsupportedPtcatalystswasslightlylower.Dopingofthecatalystwithpotassiumledtoanincreaseintheselectivityforcarbazoleby15%.BimetallicPt-Sncatalystspreparedbyco-impregnationwerelessselectivethancatalystspreparedbysuccessiveimpregnation.TheselectivityforcarbazoleoverbimetallicPt-Sncatalystspreparedbysuccessiveimpregnationwas75%,buttheiractivitydecreasedwithincreasedSnloading.HighlyactiveandreasonablyselectivecatalystswereIr-dopedbimetallicPt-basedcatalysts.TheconversionofdiphenylamineoverPt-Ircatalystswasabove98%andtheselectivityforcarbazolewasnearly55%,whilethelifetimewasmuchlonger.
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