Recent Advances on MXene‐Based Electrocatalysts toward Oxygen Reduction Reaction: A Focused Review

Abstract MXenes are novel transition‐metal‐carbide‐ and/or nitride‐based 2D materials that attract considerable attention in the field of energy storage and conversion because of their unique layered structures, electronic properties, and surface chemistries, which facilitate various electrochemical reactions. MXenes have been rarely investigated as probable catalysts or catalyst supports for the oxygen reduction reaction (ORR). In this review, recent developments in experimental and theoretical research on MXene‐based electrocatalysts for the ORR are examined. MXenes are known to have tremendous potential as stable supports for various Pt and non‐Pt metals for electrocatalytic ORR processes. Theoretical analyses have determined several potential MXene candidates for applications as supports for Pt and non‐Pt metal nanoparticles; experimental studies have shown that Pt‐ and non‐Pt‐deposited MXenes exhibit appreciable ORR activity and stability in alkaline media, followed by acidic media. However, experimental studies also indicate several limitations and challenges that must be addressed for efficient application of MXenes as supports for the ORR. Therefore, current research on MXenes with respect to the ORR is discussed, with a focus on synthesis strategies, ORR activities, and factors responsible for enhancing the electrocatalytic performance. Several strategies for the further development of efficient and durable ORR‐based MXene catalysts are also proposed.