Titanium Architectures for Durable Water Electrolysis: From MXenes and Magnéli Phases to Single-Atom Catalysts

Abstract

The urgent transition toward a carbon-neutral energy economy positions water electrolysis as a cornerstone for sustainable "green hydrogen" production. While noble-metal catalysts define current benchmarks, their prohibitive costs and scarcity necessitate the development of robust, Earth-abundant alternatives. This review provides a comprehensive analysis of advanced titanium (Ti)-based architectures-specifically 2D MXenes, Magn & eacute;li phase suboxides (TinO2n-1), and single-atom catalysts (SACs)-as transformative platforms for hydrogen and oxygen evolution reactions (HER/OER). We examine the synergistic effects of MXenes, where metallic conductivity and tunable surface terminations (Tx) optimize hydrogen adsorption energetics. Simultaneously, we highlight exceptional electrochemical stability and strong metal-support interactions (SMSI) of Magn & eacute;li phases, which effectively circumvent the "universal scaling relationship" bottlenecks in OER. Furthermore, we emphasize the integration of SACs on these Ti-based supports, where engineering the local coordination environment maximizes atom utilization and intrinsically boosts catalytic activity. A strategic emphasis is placed on direct seawater electrolysis, highlighting the "chlorophobic" and self-healing properties of Ti-interfaces that ensure long term durability against chloride corrosion and mineral scaling. By integrating AI-driven discovery and field-scale engineering perspectives, this review provides a strategic roadmap for designing high-performance, non-noble metal-based systems for industrial-scale energy conversion, offering a viable solution to the long-standing stability-activity trade-off in extreme environments.