Molecule-Level g-C₃N₄ Coordinated Transition Metals as a New Class of Electrocatalysts for Oxygen Electrode Reactions

Abstract

Organometallic complexes with metal-nitrogen/carbon (M-N/C) coordination are the most important alternatives to precious metal catalysts for oxygen reduction and evolution reactions (ORR and OER) in energy conversion devices. Here, we designed and developed a range of molecule-level graphitic carbon nitride (g-CN) coordinated transition metals (M-CN) as a new generation of M-N/C catalysts for these oxygen electrode reactions. As a proof-of-concept example, we conducted theoretical evaluation and experimental validation on a cobalt-CN catalyst with a desired molecular configuration, which possesses comparable electrocatalytic activity to that of precious metal benchmarks for the ORR and OER in alkaline media. The correlation of experimental and computational results confirms that this high activity originates from the precise M-N coordination in the g-CN matrix. Moreover, the reversible ORR/OER activity trend for a wide variety of M-CN complexes has been constructed to provide guidance for the molecular design of this promising class of catalysts.

MO‐Co@N‐Doped Carbon (M = Zn or Co): Vital Roles of Inactive Zn and Highly Efficient Activity toward Oxygen Reduction/Evolution Reactions for Rechargeable Zn–Air Battery

“…[9] Recent reports also demonstrate that N-related species are active for OER. [5,[48][49][50][51][52][53] In this work, the catalysts include both N-and metal-based species. [5,[48][49][50][51][52][53] In this work, the catalysts include both N-and metal-based species.…”

Carbon Solving Carbon's Problems: Recent Progress of Nanostructured Carbon‐Based Catalysts for the Electrochemical Reduction of CO2

“…[105] [94] which generally results in CO formation and desorption. Interestingly, due to the presence of d states contributed by the metal in M-N-C, subsequent *CO binding and protonation can occur, depending on the affinity of the metal species for CO.…”

In Situ Coupling Strategy for the Preparation of FeCo Alloys and Co4N Hybrid for Highly Efficient Oxygen Evolution

“…[1,2] The OER process nevertheless suffers from multiple steps of protoncoupled electron transfer, thereby leading to very sluggish kinetic reactions. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] As alternatives, transition metal cobalt (Co)-based catalysts show high-performance activities toward OER and held great promise for potential applications. Therefore, tremendous research efforts have been devoted to search and develop active, stable, and cost-effective OER catalysts.…”