Organic Compound Modified Cu-Based Catalysts for the Hydrogenation of Esters

Cu/SiO₂ catalysts are widely applied to the hydrogenation of dimethyl oxalate and ethylene carbonate to the corresponding ethylene glycol and methanol simultaneously, whereas ethylene glycol and methanol are important bulk commodities and raw materials for the production of oxygen-containing chemicals and fuels. However, Cu particles usually aggregate or sinter to deactivate and the ratio of surface Cu⁰/Cu⁺ species is also difficult to control under the reaction conditions, so that the catalyst activity and stability is still a big challenge. It was found that modification of Cu-based catalysts with certain organic compound inhibited the agglomeration of Cu particles, regulated the ratio of surface Cu⁰/Cu⁺ species, and even generated carbon layers to protect the Cu particles, which definitely improved the stability of the catalyst along with the enhanced catalytic performance. In this review, recent developments in ester hydrogenation over organic compound-modified Cu/SiO₂ catalysts were summarized and the issues to be further clarified are discussed as well.