焙烧温度对Cu/SiO_(2)纳米管催化剂催化草酸二甲酯加氢制乙醇酸甲酯性能的影响

Effect of calcination temperature on catalytic performance of Cu/SiO_(2) nanotube catalysts for hydrogenation of dimethyl oxalate to methyl glycolate

采用水热法合成了管状页硅酸铜前驱体,经还原得到高负载量、高分散度的Cu/SiO_(2)纳米管催化剂。通过一系列表征手段考察了焙烧温度对催化剂催化草酸二甲酯(DMO)加氢制乙醇酸甲酯(MG)反应性能的影响。结果表明,随着焙烧温度的升高,Cu物种分散度及活性比表面积先增大后减小。当焙烧温度为450℃时,催化剂中Cu^(+)物种的活性比表面积最大,催化性能最优。在反应温度为210℃、反应压力为2 MPa、n(H_(2))/n(DMO)为100、质量空速为0.839 h^(-1)时,DMO转化率为91.50%,MG选择性为60.82%,并且MG收率在250 h的长期评价中保持稳定。

The tubular copper phyllosilicate precursor was synthesized by hydrothermal method,and the Cu/SiO_(2) nanotube catalysts with high loading and high dispersion were obtained by reduction.The effect of calcination temperature on the catalytic performance for the hydrogenation of dimethyl oxalate(DMO)to methyl glycolate(MG)was investigated by a series of characterization methods.The results show that dispersion and active specific surface area of copper species first increase and then decrease with the increase of calcination temperature.When the calcination temperature is 450℃,the active specific surface area of Cu^(+)species in the catalyst is the largest and the catalytic performance is the best.When the reaction temperature is 210℃,reaction pressure is 2 MPa,n(H_(2))/n(DMO)is 100 and mass airspeed is 0.839 h^(-1),the conversion of DMO is 91.50%,and the selectivity of MG is 60.82%,and the yield of MG remains stable in the long-term evaluation of 250 h.