Unlocking the Potential of Metallene‐Based Catalysts: A Critical Review of Synthesis, Performance and Prospects

Metallenes (MLs), the two‐dimensional metallic analogs of graphene, are atomically thin sheets of metals. These materials are garnering growing interest in the field of catalysis due to their extraordinary physicochemical and electronic properties, which arise from pronounced electron‐confinement effects brought by their unique two‐dimensional structure. Their catalytic performance is intimately linked to composition, morphology, crystal structure, and thickness. Study on their controllable fabrication and exploration of suitable catalytic applications have become a research hotspot. In this review, recent progress in the state‐of‐the‐art synthetic methodologies was summarized from the aspect of (i) bottom‐up approaches, (ii) top‐down approaches, and (iii) topological metallization strategy. Then their applications across diverse areas of heterogeneous catalysis, including redox reactions, especially on the basis of electro‐ and photocatalysis are highlighted. Finally, based on these recent advances, we outlined the remaining challenges and offered perspectives on future directions from the aspects such as green and facile method for metallane preparation, expanding the scope of MLs and their catalytic applications, as well as the structure–activity relationship of metallene‐based catalysts.