Surface coordination chemistry of MXenes: defects, terminations and anchored metal sites for inorganic redox catalysis.

MXenes are usually reviewed as a broad family of two-dimensional carbides and nitrides, yet their most distinctive inorganic-chemistry feature is a dense, reactive and electronically coupled surface. This mini review frames MXenes as configurable coordination platforms rather than passive conductive supports. We discuss how terminal groups, metal vacancies, heteroatom substitution, interlayer ions, reconstruction and single-atom anchoring define local metal-ligand environments that regulate adsorption, charge transfer and catalytic selectivity. Representative examples from hydrogen evolution, oxygen electrocatalysis, single-atom-catalyst-mediated small-molecule redox chemistry, and rechargeable metal-air or lithium-oxygen chemistry are integrated with foundational studies on synthesis and surface characterization. The central message is that progress depends less on adding more components to MXene hybrids than on specifying which inorganic site is responsible for the reaction and how that site evolves under operating potentials.