Programming Cascade Catalysis in Multielement Dual‐Heterostructured Catalysts Through Gradient Adsorption Potentials

ABSTRACT Catalytic reactions involving multiple intermediates are fundamentally constrained by the limited functionality of single active sites. While multi‐site catalysts provide a promising route to decouple complex reaction steps, the rational design and realization of architectures that enable rapid and directional inter‐site intermediate spillover remains largely unexplored and highly challenging. Here, we report a strategy to program intermediate spillover and cascade catalysis in multielement dual‐heterostructured catalysts through gradient adsorption potentials. Using the acidic oxygen evolution reaction as a model, a dual‐heterostructured RuIr–Mo/WVOx catalyst is precisely engineered to integrate an oxyphilic WVOx matrix for rapid water dissociation, a Mo bridge for efficient * OHspillover, and a RuIr alloy for accelerated oxidation. Guided by first‐principles screening and differences in elemental reducibility, a continuous gradient adsorption sequence (WVOx → Mo → RuIr) is constructed from a multielement architecture, enabling directional * OH transport across cooperatively coupled active centers with balanced energetics for cascade catalysis. As a result, the optimized catalyst delivers an overpotential of 183 mV at 10 mA cm − 2 and sustains stable operation for 450 h at 100 mA cm − 2 , outperforming single‐interface and commercial benchmarks. This work establishes gradient adsorption engineering as a general design framework for programming cascade catalysis in multistep reactions.