Role of copper content and calcination temperature in the structural evolution and catalytic performance of Cu/P25 catalysts in the selective hydrogenation of dimethyl oxalate

•Copper content and calcination temperature played significant roles.•20Cu/P25-823 catalyst displays superb catalytic performance.•Yield of EG as high as 98.9% under optimized reaction conditions.•Long-term stability as 96h.•Agglomeration of copper species at higher calcination temperature.