Recent advances in platinum group metallenes: From synthesis to energy-related electrocatalytic application

Metallenes, a class of emerging two-dimensional (2D) ultrathin nanomaterials similar to graphene, have attracted widespread attention in energy-related electrocatalysis reactions due to their high atomic utilization, large surface area, and high proportion of unsaturated metal sites. Platinum group metals (PGMs) with their unfilled d orbital generally exhibit excellent electrocatalytic performance due to the favorable chemical adsorption of reactants. The PGM metallenes (PGMEs) with the unique physicochemical properties of 2D ultrathin nanomaterials present a highly competitive candidate for energy-related electrocatalysis. Therefore, understanding the structure-performance relationship and developing efficient PGMEs are critical for advancing sustainable energy-related applications. This review outlines the structural advantages of PGMEs, which are proposed to be “four inherent effects”. Three typical synthesis strategies are introduced, including confinement agents assisted method, template assisted method and topological reduction method. Then, the applicative characterization techniques of PGMEs are also summarized. Sequentially, the catalytic properties of PGMEs for small molecules (such as formic acid, methanol, ethanol and sulfur ion) electrooxidation reactions at anode and small molecules (such as oxygen, hydrogen, and nitrate) electroreduction reactions at cathode are discussed with the focus on the influence of the “four inherent effects”. Finally, we prospect the challenges and future prospects in the controlled synthesis, performance regulation strategies and energy-related applications of PGMEs. This review aims to inspire the synthesis of high-quality PGMEs and mechanistic studies to further improve the catalytic performance of PGMEs in energy-related electrocatalytic reactions. [Display omitted] •Platinum-group metallenes (PGMEs) have shown great potential applications in energy-related electrocatalysis.•The universal structural advantages of PGMEs are innovatively summarized as “four inherent effects”.•Typical top-down synthesis methods and necessary characterization techniques are introduced for understanding “four inherent effects”.•The prospect of controllable synthesis and design strategy of PGMEs is put forward.