Recent Advances in Bimetallic Site Catalysts for Photocatalytic Ammonia Synthesis: Synergistic Effects and Design Strategies

. In recent years, bimetallic active-site catalysts have become a research focus in the photocatalytic nitrogen fixation field. The synergistic effects of bimetallic active sites are used to overcome limitations of single-metal systems and optimize electronic structures. In addition to systematically summarizing the latest research advances in this field, this review is intended to delineate the potential design principles of bimetallic active sites for nitrogen fixation. These principles primarily encompass three core dimensions: the rational selection of metal element combinations, the adaptive matching of structural designs with supporting substrates, and the precise regulation of heterostructure construction processes. Notably, a central objective of this review is to establish a cohesive and in-depth understanding of the intrinsic mechanisms by which bimetallic active sites drive and facilitate the multi-step cascade reactions in nitrogen fixation. Furthermore, the development trends in catalyst modification strategies are systematically analyzed, with subsequent discussion of recent research advancements, current challenges, and prospective development directions aimed at improving energy utilization efficiency and scaling up the photocatalytic nitrogen fixation reaction.