Copper-Fiber-Structured Pd-Au-CuOx: Preparation and Catalytic Performance in the Vapor-Phase Hydrogenation of Dimethyl Oxalate to Ethylene Glycol

Cu-fiber-structured ternary Pd-Au-CuOx catalysts engineered from nano- to macro-scales have been developed for the vapor-phase dimethyl oxalate (DMO) hydrogenation to ethylene glycol (EG), with the aid of galvanic deposition of Pd and Au onto a thin-sheet microfibrous structure using 8m Cu fiber. Effects of Pd and Au loadings and their ratio have been investigated on the catalyst performance as well as the reaction conditions including reaction temperature and pressure, liquid weight hourly space velocity, and H-2/DMO ratio. The promising 0.1Pd-0.5Au-CuOx/Cu-fiber catalyst is capable of converting 97-99% DMO into EG product at a selectivity of 90-93%. This catalyst is stable for at least 200h. The Pd-Au-Cu2O synergistically promotes the hydrogenation activity and stabilizes Cu+ sites to suppress deep reduction deactivation.