pdsiw,12基催化劑的制備及其在乙烯直接氧化合成醋酸中的研究

1、大連理工大學(xué)碩士學(xué)位論文PdSiW基催化劑的制備及其在乙烯直接氧化合成醋酸中的研究姓名：房克功申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：應(yīng)用化學(xué)指導(dǎo)教師：蔡天錫王新平2001.6.1大連理工大學(xué)碩士學(xué)位論文InthisdissertationthepreparationofsupportedPdH4SiW12040catalystandthecatalyticperformanceinthedirectoxidationofethylenetoaceti

2、cacidwasexamined.Ourstudyindicatedthatthepalladiumprecursoranditsreductionmethodarethekeyfactorsfortheactivityofthecatalyst.TheactivitiesofthecatalystusingPd(NH3)4C12astheprecursorarelowerthanthoseusingH2PdC14astheprecur

3、sor.Thegasphasereductionmethodisobviouslybeterthantheliquidphasereductionmethod.Characterizationofthecatalystshowedthatthepalladiumhashigherdispersionusingthehydrogenreductionmethodthanthatusingthehydrazinereductionmetho

4、dwhichcausedthelargediscrepancyofthecatalyticactivities.Theactivityofthecatalystisstronglydependentupontheloadingamountofpalladiumandtungstosilicacid.Intherangeof03.5wt.%withtheincreaseofpalladiumloadingtheconversionofet

5、hyleneandthespacetimeyieldofaceticacid(STYACOH)increaseintherangeof040wt.%withtheincreaseoftungstosilicacidtheselectivityofdioxidedecreasesmonotonouslywhiletheSTYAcoHattainsamaximumatatungstosilicacidcontentofabout30wt.%

6、andthendeclined.AseriesofthethirdcomponentswasinvestigatedbasedonPdSiW2SiO2catalyst.ItwasfoundthatthepromotersuchasSeandTeespeciallytheincorporationofseleniumpromotercouldimprovetheselectivityofaceticacidandremarkablyenh