Strong Metal-Support Interaction Driven Janus Reconstruction in PtRu Alloys for Low-Temperature Hydrogen Storage

Janus nanostructures enable the spatial decoupling distinct catalytic functions, yet their controlled synthesis remains challenging, as bimetallic systems thermodynamically favor alloy formation. Herein, we demonstrate that strong metal-support interaction (SMSI) can drive a transformation from alloy to Janus nanoparticles. Using a PtRu alloy on CeO₂ as a model system, the inherently stronger interaction of Ru with CeO₂ directs Ru to migrate toward the metal-support interface during high-temperature reduction, thereby forcing Pt to segregate into adjacent, Pt-enriched domains. This SMSI-driven reconstruction spontaneously generates atomically intimate Janus nanoparticles, spatially partitioned Pt-rich and Ru-rich regions for H₂ dissociation and toluene adsorption, respectively. Facilitated by hydrogen spillover across the seamless interface, this spatial organization enables low-temperature hydrogen storage via toluene hydrogenation, achieving a turnover frequency of 10 906 h^-1 at 50°C. This value represents a 6.7-fold enhancement over the alloyed nanoparticles and surpasses state-of-the-art catalysts that operate above 100°C. This study establishes SMSI as a thermodynamic lever for creating multiple active sites within a single nanoparticle, offering a rational and scalable pathway to advanced catalysts for energy storage and conversion.