Reaction kinetics and selectivity of dimethyl succinate hydrogenolysis over copper-based catalysts

The vapor-phase hydrogenolysis of dimethyl succinate to yield 1,4-butanediol via the intermediate monoester has been studied over a range of copper-based catalysts. For all catalysts, the kinetics of the reaction were well described by a Langmuir-Hinshelwood-type model in which dissociatively adsorbed dimethyl succinate reacts with adsorbed molecular hydrogen. The differences in activity between the various catalysts were found to be related to the copper surface area and to the equilibrium constant for hydrogen adsorption K_H. Zinc addition to the catalyst reduced both activity and selectivity compared to pure copper. The best selectivities and high activities leading to improved 1,4-butanediol yields were obtained using Raney copper and Raney copper-chromium catalysts.