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

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 (O_vac) in Cr-doped SrTiO₃. The substitutional doping of Cr³⁺ for Ti⁴⁺ into the SrTiO₃ lattice favors the generation of more O_vac and modifies the local electronic environment. Density functional theory analysis evinces the spontaneous dissociation of COOH^# intermediates over O_vac and lower CO intermediate binding on O_vac reducing the energy demand for CO release due to Cr doping.