HYDROGENATION OF CO_2 OVER ULTRAFINECuO-ZnO-SiO_2 CATALYST-REACTION CONDITIONS AND MECHANISM

IntroductionAsoncofthemostabundantandcheapestcarbonsourccs,Co2u,ithsteadilyincreasingconcentrationintheatmospherenotonlyleadstothelossofcarbonsource,butalsocausesgrccnhouseeffects.Recently,Co2wastestedasafecdstockformcthanolproductionovcrdiffcrentcatalystsclse.'hcrell'21,butmostofthesecatalystswerebasedonthecombinationofcoppcrandzincandpreparedbycoprecipitation,ioncxchangcor'l3'4]Accordingtoextensivestudiesaboutsupports,SiO2wasoncoftheimpregnationl3'4]Accordingtoextensivestudiesaboutsupport…

HYDROGENATION OF CO2 OVER ULTRAFINE CuO-ZnO-SiO2 CATALYST-REACTION CONDITIONS AND MECHANISM

Under different reaction conditions, hydrogenation of CO2 overultraline CuO-ZnO-SiO2 catalyst prepared by alchoxide method has beenstudied. Thc main products are methanol and CO. Possible mechanism isdiscussed for the hydrogcnation of CO2 over ultrafine CuO-ZnO-SiO2catalyst and further suppported by the results of hydrogenation of CO. Therelationship between reaction pressure and relative selectivity (CH3OH/CO)and the results of hydrogenation of CO show that the methanol fromhydrogenation of CO2 comes directly from CO2 rather than from CO and theformation of methanol and CO from CO2 are parallel reactions.