Cooperative Triactive Sites of Pt ₁ –O _V -In ₆ on In ₂ O ₃ Enable Near-CO-Free H ₂ Generation via Aqueous-Phase Reforming of Methanol

Aqueous-phase reforming of methanol (APRM) represents a promising approach for dense H2 storage and on-demand release yet faces the persistent challenge of unintended CO generation. Using atomically dispersed Pt1 on In2O3 as a representative catalyst, we demonstrate that Pt1 sites dissociate methanol into *CO and *H, while adjacent oxygen vacancies (OV) on In2O3 activate H2O to generate *OH, enabling *CO to reforming to CO2. However, a slight delay in dehydrogenation intensifies *H accumulation on the catalyst surface, which alters the electronic structures of Pt1 and ultimately weakens *CO adsorption, inevitably triggering CO release. To address this fundamental challenge, we design and construct cooperative triactive sites of Pt1, OV, and hydroxyl-saturated six-coordinated In6 on Pt1/In2O3, achieving near-CO-free H2 generation (<1 ppm) through APRM at low temperatures (<180 °C). Crucially, the incorporation of In6 sites with high dehydrogenation capability ensures rapid *H depletion, effectively suppressing CO release. This strategy resolves the long-standing challenge of the ultralow CO content in H2 through APRM.