Facile synthesis of Cu@Ag/SiO2 catalysts for the selective hydrogenation of dimethyl oxalate to methyl glycolate

Abstract

A promising route for producing biodegradable polyglycolic acid material from syngas has garnered increasing attentions. In this route, one of the pivotal issues is developing favorable catalysts for semi-hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG). Silver catalysts were reported to be effective but suffered from the high cost. Herein, we prepared small-sized Cu@Ag/SiO2 catalysts with appropriate Ag/Cu ratios by a facile wet impregnation method. This core–shell structure facilitated the intermetallic electronic transference from Cu to Ag. The surface exposure of electron-rich silver species could promote the catalytic activity and MG desorption in the DMO hydrogenation, which achieved high efficiency without compromising the MG selectivity. The optimal catalyst with Ag/Cu mass ratio of 3/2 displayed excellent space time yield towards MG of 47.3 g·gAg−1·h−1. These insights could offer a potential strategy to reduce the silver-based catalyst cost for the semi-hydrogenation of DMO to MG.