Current advances and performance enhancement of single atom M-N-C catalysts for PEMFCs

Abstract

Single-atom transition metal-nitrogen-doped carbons (SA M-N-Cs) catalysts are promising alternatives to platinum-based catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). However, enhancing their performance for practical applications remains a significant challenge. This review summarizes recent advances in enhancing the intrinsic activity of SA M-N-C catalysts through various strategies, such as tuning the coordination environment and local structure of central metal atoms, heteroatom doping, and the creation of dual-/multi metal sites. Additionally, it discusses methods to increase the density of M-N_x active sites, including chelation, defect capture, cascade anchoring, spatial confinement, porous structure design, and secondary doping. Finally, it outlines future directions for developing highly active and stable SA M-N-C catalysts, providing a comprehensive framework for the design of advanced catalysts.

Graphical abstract

Keywords

single atom catalysts / metal-nitrogen-carbon / oxygen reduction reaction (ORR) / catalytic performance / proton exchange membrane fuel cells (PEMFCs)

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