摘要
针对草酸二甲酯(DMO)加氢制备乙醇酸甲酯(MG)反应中,银(Ag)基催化剂成本较高、催化性能不稳定等问题,为降低成本并提高催化性能,以水热合成法制备的树枝状纤维形二氧化硅纳米球(KCC-1)为载体,采用等体积浸渍法制备Ag/KCC-1、Ag-Ni/KCC-1 负载型催化剂.考察了Ag的较优负载量及总负载量不变时,Ag与镍(Ni)较佳的质量比.结果表明,Ag/KCC-1 催化剂中,不同Ag负载量的催化剂,其结构和催化性能均有所不同,Ag负载量(质量分数)为 15%时,性能较好;Ag-Ni/KCC-1 催化剂中,适量Ni的引入对催化剂的结构和催化性能均有明显提高,当Ag和Ni的负载量分别为 12%和 3%时,催化性能较佳,与单组分负载的Ag/KCC-1 催化剂相比,DMO转化率由 90.37%提高至 96.75%,MG转化率由 90.77%提高至 92.48%,MG收率由 82.04%提高至 89.47%.
Abstract
Sliver(Ag)based catalyst has high cost and unstable catalytic performance in dimethyl oxalate(DMO)hydrogenation to prepare methylglycolate(MG).In order to reduce cost and improve catalytic performance,dendritic fibrous silica nanospheres(KCC-1)prepared by hydrothermal synthesis was used as the carrier.Ag/KCC-1 and Ag-Ni/KCC-1 supported catalysts were prepared by constant volume impregnation method.The optimal load of Ag and the optimal mass ratio of Ag to Ni under constant total load were investigated.The results show that the structure and catalytic performance of the catalysts with different Ag loadings are different,and the performance is better when the Ag loading is 15%.Addition of appropriate amount of Ni can significantly improve the structure and catalytic performance of the catalyst.The catalytic performance is better when the loading of Ag and Ni are 12%and 3%,respectively.Compare with the single-component support Ag/KCC-1 catalyst,DMO conversion rate is increased from 90.37%to 96.75%,MG conversion rate is increased from 90.77%to 92.48%and MG yield is increased from 82.04%to 89.47%.
维普
万方数据