Favoring Product Desorption by a Tailored Electronic Environment of Oxygen Vacancies in SrTiO3 via Cr Doping for Enhanced and Selective Electrocatalytic CO2 to CO Conversion.

Abstract

The electrochemical CO2 reduction reaction (ECO2RR) into value-added products is crucial to address the herculean task of CO2 mitigation. Several efforts are being made to develop active ECO2RR catalysts, targeting enhanced CO2 adsorption and activation. A rational design of ECO2RR catalysts with a facile product desorption step is seldom reported. Herein, ensuing the Sabatier principle, we report a strategy for an enhanced ECO2RR with a faradaic efficiency of 85% for CO production by targeting the product desorption step. The energy barrier for product desorption was lowered via a tailored electronic environment of oxygen vacancies (Ovac) in Cr-doped SrTiO3. The substitutional doping of Cr3+ for Ti4+ into the SrTiO3 lattice favors the generation of more Ovac and modifies the local electronic environment. Density functional theory analysis evinces the spontaneous dissociation of COOH# intermediates over Ovac and lower CO intermediate binding on Ovac reducing the energy demand for CO release due to Cr doping.