简介:ATi/Sicomplexzeolitehasbeenprepared.X-raydiffractionandinfraredspectrometrystudyhasshownthattwostructures,namelytheZSM-5andMCM-41,existinthesample.BETtestshaverevealedthatthecomplexzeolitecontainsregularmesoporesof2.6nm.UltravioletspectrometryanalysishasshownthattheTispeciesexistinthezeoliteskeletonintheformoftetra-coordinatevalence.TheTi/Sicomplexzeolite(TS-1/Ti-MCM-41)hasapparentlyimprovedcatalyticactivitywithrespecttothemacromolecularorganiccompoundoxidationascomparedtoindividualcomponentsofeitherTiorSicontainingzeolites(TS-1andTi-MCM-41).
简介:Chromiumacetylacetonateandbis(diphenylphosphino)isopropylaminewerecoordinatedinsituandsupportedonmethylaluminoxane-modifiedsilica.Thecatalyststructureandeffectsofreactiontemperature,reactionpressureandAl/Crmolarratioonethylenetetramerizationwereinvestigatedindetail.Chromiumwasuniformlyandfirmlyimmobilizedonthesupportandcouldnotbeleachedoffbymethylaluminoxane.Thesupportedcatalyst,uponbeingactivatedwithmethylaluminoxane,exhibitedcatalyticactivityof1.70×107g/(molCr·h)forethylenetetramerizationtoform1-octeneatareactiontemperaturesof80℃,apressureof2.0MPaandanAl/Crmolarratioof300.Thesupportedcatalystpresentedagoodtolerancetohightemperature.