MOF and MXene-derived atom-level catalysts (Fe, co and Ni): Trends, breakthroughs, and challenges in water splitting

Abstract

Developing efficient and cost-effective catalysts for industrial-scale hydrogen (H2) and oxygen (O2) production is crucial for the clean energy transition. Atomically dispersed single-atom catalysts (AD SACs) (e.g., iron (Fe), cobalt (Co), and nickel (Ni)) without precious metals are particularly promising, offering 100% atomic utilization and optimum catalytic efficiency. Nonetheless, key challenges remain, including the suppression of atom aggregation, the optimization of support structures, and the maintenance of stability. Moreover, industrial catalysis demonstrates that active components with suitable supports are critical, and catalytic efficacy often increases as the size of the active components decreases, opening new frontiers in catalyst design. Thus, metal-organic frameworks (MOFs) and MXenes have emerged as effective anchoring matrices, enabling modulation of electronic structures, rapid charge transfer, and enhanced stabilization of single metal atoms. This review highlights recent progress in the development of AD SACs anchored on MOFs and MXenes, emphasizing the fundamental parameters governing hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance. Furthermore, we integrate theoretical insights from Density Functional Theory (DFT) with advanced operando and in-situ characterization techniques to provide a comprehensive understanding of the mechanistic origins governing HER/OER activity. We anticipate that these insights will contribute to improving water-splitting efficiency and sustainability, which are vital for advancing the clean energy revolution. Finally, this review outlines future directions for the development of high-efficiency, cost-effective MXene-and MOF-based SAC catalysts, underscoring their potential in clean energy production.