[2Fp01-09] Surface Science(SS2) Chemical Property

[2Fp07] Unraveling hydrogen spillover pathways of reducible metal oxides

*Kazuki Shun¹, Kohsuke Mori¹, Hiromi Yamashita¹ (1. Graduate School of Engineering, Osaka University)

Hydrogen spillover, the migration of dissociated hydrogen atoms from noble metal catalysts to their support materials, is a ubiquitous phenomenon and is widely utilized in heterogeneous catalysis and hydrogen storage materials. However, in-depth understanding of the migration of spilled hydrogen over different types of supports is still lacking. Herein, hydrogen spillover pathways in typical reducible metal oxides, such as TiO₂, CeO₂, and WO₃, were elucidated. TiO₂ and CeO₂ were proven to be promising platforms for the synthesis of non-equilibrium RuNi solid solution alloy nanoparticles displaying enhanced catalytic activity in the hydrolysis of ammonia borane. Such behavior was driven by the simultaneous reduction of both cations under a H₂ atmosphere over TiO₂ and CeO₂, in which hydrogen spillover favorably occurred over their surfaces rather than within their bulk phases. Conversely, hydrogen atoms were found to preferentially migrate within the bulk prior to the surface over WO₃.