Regulation of Electrocatalytic Behavior by Axial Oxygen Enhances the Catalytic Activity of CoN<sub>4</sub> Sites for CO<sub>2</sub> Reduction
Zhaodi Wang, Ye Han, Bo Li, Peng Peng, Shuang‐Quan Zang
Abstract
Abstract Recent studies have found that the existence of oxygen around the active sites may be essential for efficient electrochemical CO 2 ‐to‐CO conversion. Hence, this work proposes the modulation of oxygen coordination and investigates the as‐induced catalytic behavior in CO 2 RR. It designs and synthesizes conjugated phthalocyanine frameworks catalysts (CPF‐Co) with abundant CoN 4 centers as an active source, and subsequently modifies the electronic structure of CPF‐Co by introducing graphene oxide (GO) with oxygen‐rich functional groups. A systematic study reveals that the axial coordination between oxygen and the catalytic sites could form an optimized O‐CoN 4 structure to break the electron distribution symmetry of Co, thus reducing the energy barrier to the activation of CO 2 to COOH*. Meanwhile, by adjusting the content of oxygen, the proper supports can also facilitate the charge transfer efficiency between the matrix layer and the catalytic sites. The optimized CPF‐Co@LGO exhibits a high TOF value (2.81 s −1 ), CO selectivity (97.6%) as well as stability (24 h) at 21 mA cm −2 current density. This work reveals the modulation of oxygen during CO 2 RR and provides a novel strategy for the design of efficient electrocatalysts, which may inspire new exploration and principles for CO 2 RR.