The Functionality of Surface Hydroxyls on Selectivity and Activity of CO2 Reduction over Cu2O in Aqueous Solutions.

The Functionality of Surface Hydroxyls on Selectivity and Activity of CO2 Reduction over Cu2O in Aqueous Solutions.
Angew Chem Int Ed Engl. 2018 Apr 19;:
Authors: Gong J, Yang P, Zhao ZJ, Chang X, Zha S, Zhang G, Mu R
Abstract
CO2 reduction in aqueous solutions is an attractive strategy for carbon capture and utilization. Cuprous oxide (Cu2O) is a promising catalyst for CO2 reduction as it can not only convert CO2 into valuable hydrocarbons but also suppress the side H2 evolution reaction (HER). However, the nature of the active sites is still under debate due to the complex surface structure of Cu2O under reducing conditions, leading to limited guidance in designing improved Cu2O catalysts. This paper describes the functionality of surface bounded hydroxyls on over partially reduced Cu2O(111) for CO2 reduction reaction (CO2RR) by combined density functional theory (DFT) calculations and experimental studies. We find that the surface hydroxyls play a crucial role in CO2RR and HER, and a moderate coverage of hydroxyls is the optimal to promote CO2RR and suppress HER simultaneously. Electronic structure analysis indicates that the charge transfer from hydroxyl groups to coordination-unsaturated Cu (CuCUS) sites stabilizes surface adsorbed COOH*, which is a key intermediate during CO2RR. Moreover, we evaluate the CO2RR performances over Cu2O octahedron catalysts of {111} facets with different surface coverages of hydroxyls, which demons...

Source: Angewandte Chemie - April 19, 2018 Category: Chemistry Authors: Gong J, Yang P, Zhao ZJ, Chang X, Zha S, Zhang G, Mu R Tags: Angew Chem Int Ed Engl Source Type: research