Catalytic behaviors of CuCo/SiO_2 catalyst for hydrogenation of CO to lower alcohols

CuCo/SiO2 bimetallic catalyst was prepared by co-impregnation and its catalytic behaviors were investigated using CO hydrogenation to lower alcohols as the model reaction,including the influence of reaction temperature,reaction pressure and space velocity.The catalyst was characterized by XRD,TG and TPR.CO conversion increased from 14.9% to 40.4% while reaction temperature was raised from 533 K to 563 K;the space timely yield(STY) of alcohols first increased then declined with temperature,with maximum STY at 553 K;the selectivity to lower alcohols significantly increased with pressure.When space velocity was raised from 1 200 h-1 to 4 800 h-1,CO hydrogenation activity declined while selectivity to and hence STY of lower alcohols increased remarkably.XRD results indicated that main components of the catalyst were CuO,Co3O4 and Cu-Co spinel before the reaction and Cu0 and Co2+ after the reaction.The appropriate calcination temperature of the precursor was determined at 623 K by TG.TPR results showed the optimal in situ reduction temperature was 593 K.