Accelerating Water Dissociation by Interfacial Conductance Clamp

Overcoming the activation barrier of water dissociation remains a key bottleneck in hydrogen energy conversion. Here we report our experimental discovery of an interfacial conductance clamp effect that markedly enhances catalytic performance. By constructing a Ru-Ni single-atom alloy on VO₂, we engineer the metal-semiconductor interface and promote directional electron transfer from VO₂ to Ru. The resultant charge redistribution leads to localized electron accumulation at the interface, forming a conductance clamp that facilitates activation of water molecules. Electrical measurements provide direct evidence of this interfacial phenomenon and reveal a strong correlation between the conductance clamp and enhanced catalytic activity. As a result, the catalyst with Ru₂Ni₈-VO₂ interfaces achieves a record-high turnover frequency of 1543 min^-1 in ammonia borane hydrolysis, highlighting the role of the conductance clamp in accelerating water dissociation. This work unveils a previously unrecognized interfacial mechanism, offering a powerful strategy for designing high-performance catalysts in energy conversion systems.