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

Theelectrochemical CO2 reduction reaction (ECO2RR) into value-added products is crucial to address the herculeantask of CO2 mitigation. Several efforts are being madeto develop active ECO2RR catalysts, targeting enhancedCO(2) adsorption and activation. A rational design of ECO2RR catalysts with a facile product desorption step is seldomreported. Herein, ensuing the Sabatier principle, we report a strategyfor an enhanced ECO2RR with a faradaic efficiency of 85%for CO production by targeting the product desorption step. The energybarrier for product desorption was lowered via a tailored electronicenvironment of oxygen vacancies (O-vac) in Cr-doped SrTiO3. The substitutional doping of Cr3+ for Ti4+ into the SrTiO3 lattice favors the generationof more O-vac and modifies the local electronic environment.Density functional theory analysis evinces the spontaneous dissociationof COOH# intermediates over O-vac and lower COintermediate binding on O-vac reducing the energy demandfor CO release due to Cr doping.

Automated summary

A strategy for enhanced electrochemical CO2 reduction reaction (ECO2RR) with a faradaic efficiency of 85% for CO production is reported. The energy barrier for product desorption was lowered by tailored electronic environment of oxygen vacancies (O-vac) in Cr-doped SrTiO3. The generation of more O-vac and modification of local electronic environment by Cr3+ doping promotes the spontaneous dissociation of COOH# intermediates over O-vac and reduces the energy demand for CO release.