Authors: Qiyou Wang, Kang Liu, Kangman Hu, Chao Cai, Huangjingwei Li, Hongmei Li, Matias Herran, Ying-Rui Lu, Ting-Shan Chan, Chao Ma, Junwei Fu, Shiguo Zhang, Ying Liang, Emiliano Cortés, Min Liu
Published: 2022-10-14
DOI: 10.1038/s41467-022-33692-0
Source: Full article
AbstractAtomically dispersed transition metals on carbon-based aromatic substrates are an emerging class of electrocatalysts for the electroreduction of CO2. However, electron delocalization of the metal site with the carbon support via d-π conjugation strongly hinders CO2activation at the active metal centers. Herein, we introduce a strategy to attenuate the d-π conjugation at single Ni atomic sites by functionalizing the support with cyano moieties. In situ attenuated total reflection infrared spectroscopy and theoretical calculations demonstrate that this strategy increases the electron density around the metal centers and facilitates CO2activation. As a result, for the electroreduction of CO2to CO in aqueous KHCO3electrolyte, the cyano-modified catalyst exhibits a turnover frequency of ~22,000 per hour at −1.178 V versus the reversible hydrogen electrode (RHE) and maintains a Faradaic efficiency (FE) above 90% even with a CO2concentration of only 30% in an H-type cell. In a flow cell under pure CO2at −0.93 V versus RHE the cyano-modified catalyst enables a current density of −300 mA/cm2with a FE above 90%.