Gas-phase oxycarbonylation of methanol for the synthesis of dimethyl carbonate using copper-based Supported Ionic Liquid Phase (SILP) catalysts

Catalyst systems for the gas-phase oxycarbonylation of methanol often suffer from low catalyst activities and strong catalyst deactivation. In this work, the continuous gas-phase oxycarbonylation of methanol was realized by using Supported Ionic Liquid-Phase (SILP) catalysts. Copper(I) bromide dissolved in various ionic liquids and dispersed on Polymer-Based Spherical Activated Carbon (PBSAC) as supporting material was found to be an active catalyst. The poor activity and stability of copper halide catalysts reported in literature was substantially increased by the presence of ionic liquids. In particular, trioctylmethylammonium bromide in combination with a basic salt additive increased the activity of the CuBr catalyst and led to comparatively stable SILP catalyst operation reaching a total turnover number of 600 over 50 h time-on-stream.