Saturated Coordination Lu-N6 Defect Sites for Highly Efficient Electroreduction of CO2

Metal single-atom and internal structural defects typically coexist in M-N-C materials obtained through the existing basic pyrolysis processes. Identifying a correlation between them to understand the structure-activity relationship and achieve efficient catalytic performance is important, particularly for the rare-earth (RE) elements with rich electron orbitals and strong coordination capabilities. Herein, a novel single-atom catalyst based on the RE element lutetium is successfully synthesized on a N-C support. Structural and simulation analyses demonstrate that the formation of a Lu-N-6 structural site with an individual defect because of pyrolysis is thermodynamically favorable in Lu-N-C. Using KHCO3-based electrolytes facilitates the fall of the K+ cations into the defective sites of Lu-N-C, thus enabling improved CO2 capture and activation, which increases the catalyst conductivity for Lu-N-C. In this study, the catalyst exhibits a Faradaic efficiency of 95.1% for CO at a current density of 18.2 mA cm(-2) during carbon dioxide reduction reaction. This study thus provides new insights into understanding RE-N-C materials for energy utilization.

Automated summary

Metal single-atom and internal structural defects often coexist in M-N-C materials obtained through pyrolysis. Understanding the correlation between them is important for efficient catalytic performance, especially for rare-earth elements. In this study, a novel single-atom catalyst based on lutetium is synthesized on a N-C support. The catalyst shows improved CO2 capture and activation, resulting in high Faradaic efficiency for CO during carbon dioxide reduction reaction.