Transition metal doping enhances catalytic selectivity and activity of Pt13 nanoclusters for the reduction of CO2 to CO

Abstract

Electrochemical CO2 reduction to value-added chemicals provides an efficient way to lower global warming if using efficient and selective electrocatalysts. However, the search and design of such electrocatalysts remain a considerable challenge. Here, in this work, the performance of Pt13−nMn (M = Mn, Fe, Co, Ni, Cu, and Zn) bimetallic catalysts was systematically studied in this work using spin-polarized density functional theory calculations. The Gibbs free energy results show that the doping of Mn to the Pt clusters was more beneficial to the improvement of the catalyst activity, following is the addition of Zn and Co. Among all the clusters, 15 nanoclusters are promising catalysts with a barrier of ΔG <1 eV. The Pt8Mn5, Pt2Mn11, and Pt11Mn2 are the three most promising catalysts with the barrier of only 0.148, 0.237, and 0.286 eV, respectively, displaying all more than 1 eV lower than that of pure Pt13. For most of the Pt13−nMn (M = Mn, Fe, Co, Ni, Cu, and Zn) systems, the desorption of CO is the rate-limiting step. The d band center of Pt8Mn5 is far from the Fermi energy level, which causes CO detachment more easily from Pt8Mn5. Pt8Mn5 exhibits superior catalytic activity toward CO. The study can be used to guide the design of bimetallic catalysts in the future.