In Operando Identification of In Situ Formed Metalloid Zinc^δ+ Active Sites for Highly Efficient Electrocatalyzed Carbon Dioxide Reduction

Abstract

Electrochemical CO₂ -to-CO conversion provides a possible way to address problems associated with the greenhouse effect; however, developing low-cost electrocatalysts to mediate high-efficiency CO₂ reduction remains a challenge on account of the limited understanding of the nature of the real active sites. Herein, we reveal the Zn^δ+ metalloid sites as the real active sites of stable nonstoichiometric ZnO_x structure derived from Zn₂ P₂ O₇ through operando X-ray absorption fine structure analysis in conjunction with evolutionary-algorithm-based global optimization. Furthermore, theoretical and experimental results demonstrated that Zn^δ+ metalloid active sites could facilitate the activation of CO₂ and the hydrogenation of *CO₂ , thus accelerating the CO₂ -to-CO conversion. Our work establishes a critical fundamental understanding of the origin of the real active center in the zinc-based electrocatalysts for CO₂ reduction reaction.