一种P改性的Ag/SiO_(2)催化剂用于草酸二甲酯加氢制乙醇酸甲酯

A P-modified Ag/SiO_(2)catalyst was used for the hydrogenation of dimethyl oxalate to methyl glycolate

采用浸渍法分别制备了负载于不同载体的P改性Ag1P/TiO_(2)、Ag1P/ZrO_(2)、AgxP/SiO_(2)催化剂,并用于草酸二甲酯(DMO)加氢制乙醇酸甲酯(MG)的反应中。结果表明,相对于Ag1P/TiO_(2)、Ag1P/ZrO_(2)催化剂,AgxP/SiO_(2)比表面积较大,其中Ag1P/SiO_(2)显示出最大的比表面积及孔容,从而增大了Ag的分散度。P的适量掺杂有助于对H_(2)吸附量的调控,防止过度加氢,从而获得MG的高选择性,而过量的P会导致P5+物种的形成,对反应不利。优选后的最佳催化剂Ag1P/SiO_(2)在最优反应条件下DMO转化率达到94.27%,MG选择性达到92.22%,MG的收率为86.94%。

P-modified Ag1P/TiO_(2),Ag1P/ZrO_(2)and AgxP/SiO_(2)catalysts supported on different supports were prepared by impregnation method and used in the hydrogenation of dimethyl oxalate(DMO)to methyl glycolate(MG).The results show that the specific surface area of AgxP/SiO_(2)is larger than that of Ag1P/TiO_(2)and Ag1P/ZrO_(2)catalysts.Among them,Ag1P/SiO_(2)shows the largest specific surface area and pore volume,which increases the dispersion of Ag.The appropriate amount of P doping is helpful to regulate the amount of H_(2)adsorption and prevent excessive hydrogenation,so as to obtain high selectivity of MG,while excessive P will lead to the formation of P5+species,which is unfavorable to the reaction.Under the optimal reaction conditions,the conversion of DMO reached 94.27%,the selectivity of MG reached 92.22%,and the yield of MG was 86.94%.