Photo-thermal Cooperative Carbonylation of Ethanol with CO2 on Cu2 O-SrTiCuO3-x.

Abstract

Carbonylation of ethanol with CO2 as carbonyl source into value-added esters is of considerable significance and interest, while remains of great challenge due to the harsh conditions for activation of inert CO2 in that the harsh conditions result in undesired activation of α-C-H and even cleavage of C-C bond in ethanol to deteriorate the specific activation of O-H bond. Herein, we propose a photo-thermal cooperative strategy for carbonylation of ethanol with CO2 , in which CO2 is activated to reactive CO via photo-catalysis with the assistance of *H from thermally-catalyzed dissociation of alcoholic O-H bond. To achieve this proposal, an interfacial site and oxygen vacancy both abundant SrTiCuO3-x supported Cu2 O (Cu2 O-SrTiCuO3-x ) has been designed. A production of up to 320 μmol g-1 h-1 for ethyl formate with a selectivity of 85.6 % to targeted alcoholic O-H activation has been afforded in photo-thermal assisted gas-solid process under 3.29 W cm-1 of UV/Vis light irradiation (144 °C) and 0.2 MPa CO2 . In the photo-driven activation of CO2 and following carbonylation, CO2 activation energy decreases to 12.6 kJ mol-1 , and the cleavage of alcoholic α-C-H bond has been suppressed.