Theoretical study of CO2 electrochemical reduction on Cu(111) and Sn@Cu(111) surface in presence of water.

• CO 2 reduction on clean and Sn doped Cu (111) with water presence is studied by DFT. • Favorable CO 2 reduction pathways towards HCOOH and CH 3 OH production are determined. • Sn-doped Cu (111) promotes CH 3 OH formation kinetics in the presence of water. Carbon dioxide (CO 2) electrochemical reduction is an important technique for CO 2 utilization. Sn-doped Cu-based catalysts usually shows good activity for CO 2 reduction reaction. However, the effect of Sn-dopant in the presence of water solvent is rarely studied. This is critical because CO 2 electrochemical reduction occurs at catalyst/electrolyte interface. In this work, H-shuttling and water-solvated solvent models are considered, and the mechanism of HCOOH and CH 3 OH production through CO 2 reduction on clean and Sn doped Cu(111) surfaces in presence of H 2 O is systematically investigated by density functional theory calculations. The results show that, in presence of H 2 O molecule, the rate-limiting step toward CH 3 OH production is found to be the reduction of CO 2 into COOH on both the Cu(111) and Sn@Cu(111) surfaces. However, the addition of Sn lowers the activation barrier of this rate control step, and thus makes Sn@Cu(111) more conductive to the formation of CH 3 OH. Also, the calculations also show that Sn doping exhibits no significant effect on the formation of HCOOH. The result provides a deep insight on the Sn doped Cu-based catalyst for CO 2 electrochemical reduction reaction. [Display omitted] [ABSTRACT FROM AUTHOR]