Asymmetric dinitrogen-coordinated nickel single-atomic sites for efficient CO2 electroreduction

Rational design of electrocatalysts for selective CO2 conversion is of great interests. Here the authors show that Ni single atom with asymmetric pyrrolic and pyridinic nitrogen for efficient CO2 electroconversion to CO. Developing highly efficient, selective and low-overpotential electrocatalysts for carbon dioxide (CO2) reduction is crucial. This study reports an efficient Ni single-atom catalyst coordinated with pyrrolic nitrogen and pyridinic nitrogen for CO2 reduction to carbon monoxide (CO). In flow cell experiments, the catalyst achieves a CO partial current density of 20.1 mA cm(geo)(-2) at -0.15 V vs. reversible hydrogen electrode (V-RHE). It exhibits a high turnover frequency of over 274,000 site(-1) h(-1) at -1.0 V-RHE and maintains high Faradaic efficiency of CO (FECO) exceeding 90% within -0.15 to -0.9 V-RHE. Operando synchrotron-based infrared and X-ray absorption spectra, and theoretical calculations reveal that mono CO-adsorbed Ni single sites formed during electrochemical processes contribute to the balance between key intermediates formation and CO desorption, providing insights into the catalyst's origin of catalytic activity. Overall, this work presents a Ni single-atom catalyst with good selectivity and activity for CO2 reduction while shedding light on its underlying mechanism.

Automated summary

Developing efficient electrocatalysts for selective CO2 conversion is important. In this study, the authors demonstrate that a Ni single-atom catalyst coordinated with pyrrolic nitrogen and pyridinic nitrogen efficiently converts CO2 to CO. The catalyst shows high CO partial current density and turnover frequency, as well as excellent Faradaic efficiency of CO. The study also provides insights into the origin of the catalyst's catalytic activity.