Elevating dimethyl oxalate hydrogenation activity over core–shell Cu/SiO2@CeO2 catalysts

Increasing dimethyl oxalate (DMO) hydrogenation activity remains a challenge. A Cu catalyst was designed by creating Cu nanoparticles (NPs) over SiO 2 layer formed on the CeO 2 particles (SiO 2 @CeO 2 ) using the ammonia evaporation method followed by the calcination and reduction step. The optimized 30Cu/SiO 2 @5CeO 2 catalyst shows good performance in the micro-packed bed reactor (100 % DMO conversion, 95.9 % ethylene glycol (EG) selectivity, 200 h stability) under the condition of the ratio of H 2 to DMO (H 2 /DMO) = 30, 190 °C and 2 MPa in the run, and CeO 2 was proved to be effective in the DMO hydrogenation process. The exposed CeO 2 on the surface of catalyst was found to facilitate the formation of Cu + by its interaction between adjacent Cu nanoparticles, resulting in the faster adsorption and dissociation of C=O bond on the catalyst surface, according to the characterization results obtained by the XRD, XPS and in situ FT-IR, etc.