Heterointerfaced nanostructures for complex energy electrocatalysis: a decoupling-integration strategy

Complex energy electrocatalytic reactions, such as CO₂ reduction, nitrogen conversion reactions, and C-N coupling, are promising pathways for sustainable energy conversion and green chemical synthesis. However, their efficiency and selectivity are fundamentally limited by adsorption-energy scaling relationships and functional constraints of conventional single-site catalysts. Inspired by biological enzyme systems, this review summarizes the emerging "decoupling-integration" strategy for addressing these challenges. By constructing spatially separated yet functionally interconnected active sites within heterointerfaced nanostructures, complex reaction pathways can be divided into independently optimized elementary steps while maintaining efficient communication between spatially separated catalytic functions. Such architectures enable tandem catalysis, local microenvironment regulation, interfacial charge redistribution, and cooperative pathway control, thereby significantly enhancing catalytic activity, selectivity, and stability. Representative heterointerfaced architectures, including Janus nanostructures, core-shell systems, supported heterojunctions, and hierarchically integrated composite heterostructures, are systematically discussed. Their structural characteristics, catalytic mechanisms, and advantages in regulating intermediate adsorption, accumulation, transport, and conversion are highlighted through representative studies of CO₂ reduction, nitrogen conversion, C-N coupling, and related multistep electrocatalytic reactions. Particular emphasis is placed on how interfacial engineering and spatial functional compartmentalization help overcome kinetic mismatches, suppress side reactions, and break scaling-relation limitations. Finally, current challenges and future perspectives are discussed, including operando mechanistic characterization, atomic-level interfacial regulation, catalyst stability under industrial conditions, data-driven catalyst design, and expansion toward other complex electrosynthetic reactions.