Synergistic Cr2O3@Ag Heterostructure Enhanced Electrocatalytic CO2 Reduction to CO

The electrocatalytic CO2RR to produce value-added chemicals and fuels has been recognized as a promising means to reduce the reliance on fossil resources; it is, however, hindered due to the lack of high-performance electrocatalysts. The effectiveness of sculpturing metal/metal oxides (MMO) heterostructures to enhance electrocatalytic performance toward CO2RR has been well documented, nonetheless, the precise synergistic mechanism of MMO remains elusive. Herein, an in operando electrochemically synthesized Cr2O3-Ag heterostructure electrocatalyst (Cr2O3@Ag) is reported for efficient electrocatalytic reduction of CO2 to CO. The obtained Cr2O3@Ag can readily achieve a superb FECO of 99.6% at -0.8 V (vs RHE) with a high J(CO) of 19.0 mA cm(-2). These studies also confirm that the operando synthesized Cr2O3@Ag possesses high operational stability. Notably, operando Raman spectroscopy studies reveal that the markedly enhanced performance is attributable to the synergistic Cr2O3-Ag heterostructure induced stabilization of CO2 center dot-/*COOH intermediates. DFT calculations unveil that the metallic-Ag-catalyzed CO2 reduction to CO requires a 1.45 eV energy input to proceed, which is 0.93 eV higher than that of the MMO-structured Cr2O3@Ag. The exemplified approaches in this work would be adoptable for design and development of high-performance electrocatalysts for other important reactions.