As-synthesized Raney Cu catalysts through selective leaching of Cu-Al (50 wt%Cu-50 wt%Al) alloy pellets in sodium hydroxide solution have been systematically investigated during the catalyst preparation process. Results reveal that the microstructures, physicochemical and surface properties of the Raney Cu catalysts depend profoundly on the leaching temperature. In gas-phase hydrogenation of dimethyl oxalate (DMO), the Raney Cu catalysts prepared at the mild leaching conditions tend to deactivate rapidly, the formation of methyl glycolate (MG). As-prepared catalysts at higher leaching temperature exhibit excellent stability, favoring the synthesis of ethylene glycol (EG). Especially, Raney Cu catalyst obtained at 40 degrees C shows the superior stability and MG selectivity of 95.0% in DMO hydrogenation. Furthermore, the reasons for deactivation of Raney Cu catalyst in DMO hydrogenation have been discussed in detail. (C) 2015 Elsevier B.V. All rights reserved.