Oxidative carbonylation has attracted broad interest from both academia and industry in recent years. Oxycarbonylation of ethanol to diethyl carbonate (DEC) has been of great challenge due to the difficulty in the simultaneous activation of ethanol and CO. This work reports a heterogeneous Cu-Pd pair catalysis for simultaneous activation of ethanol and CO, affording a selectivity of 85.4% to DEC and a space-time yield (STY) of up to 207 mg.g(-1).h(-1). Well distributed Cu-Pd pair affords more Cu (I) sites, promoting CO activation and the followed insertion to adsorbed ethanol. Further increasing ratio of Cu (I) species via the pre-treatment of catalyst with CO and ethanol promotes simultaneously the activation of ethanol and CO, affording a STY of 325 mg.g(-1).h(-1) of DEC. (C) 2020 Elsevier Inc. All rights reserved.