K2O对合成DMC用Cu-Ni/V2O5-SiO2催化剂性能的影响

Effect of K2O on Properties of Cu-Ni/V2O5-SiO2 Catalyst for the Synthesis of Dimethyl Carbonate

V2O5 SiO2(VSiO) supported Cu Ni K2O catalysts for the synthesis of dimethyl carbonate were prepared using isovolumic impregnation. Based on TPR,TPD, IR and micro reactor techniques, the effect of K2O on the adsorption and reaction of CO2 and CH3OH on the catalyst were characterized. The results show that addition of K2O exerts obvious influence on the charge distribution of the active sites on Cu Ni/VSiO catalyst,increases the intensities of CO2 horizontal adsorption state, while that of the dissociation state of methanol descends. When the ratio of K is above 15 ％, K2CO3 is formed on the catalyst. Moreover,the main reaction products of CO2 and CH3OH on Cu Ni K2O/VSiO catalyst are still DMC, H2O, CO and CH2O,and with the addition of K2O, the conversion of reactants rise, but the selectivity of by-products decreases.