Transition metal-nitrogen sites for electrochemical carbon dioxide reduction reaction

Electrochemical CO 2 reduction reaction (CO 2 RR) powered by renewable electricity has emerged as the most promising technique for CO 2 conversion, making it possible to realize a carbon-neutral cycle. Highly efficient, robust, and cost-effective catalysts are highly demanded for the near-future practical applications of CO 2 RR. Previous studies on atomically dispersed metal-nitrogen (M-N x ) sites constituted of earth abundant elements with maximum atom-utilization efficiency have demonstrated their performance towards CO 2 RR. This review summarizes recent advances on a variety of M-N x sites-containing transition metal-centered macrocyclic complexes, metal organic frameworks, and M-N x -doped carbon materials for efficient CO 2 RR, including both experimental and theoretical studies. The roles of metal centers, coordinated ligands, and conductive supports on the intrinsic activity and selectivity, together with the importance of reaction conditions for improved performance are discussed. The mechanisms of CO 2 RR over these M-N x -containing materials are presented to provide useful guidance for the rational design of efficient catalysts towards CO 2 RR. Metal-nitrogen sites constituted of earth abundant elements with maximum atom-utilization efficiency have emerged as promising catalysts for electrochemical CO 2 reduction reaction.