Oxygen vacancy-rich NH₂-W₁₈O₄₉ supported PdAu catalyst with enhanced hydrogen spillover for formic acid dehydrogenation and CO₂ hydrogenation

A reversible carbon-neutral hydrogen storage and release system can be realized by formic acid (FA) dehydrogenation and CO₂ hydrogenation back to formate, which, however, relies on the development of efficient catalysts. Herein, we report the synthesis of PdAu alloy nanoparticles supported on NH₂-modified W₁₈O₄₉, which exhibits superior catalytic activity for both FA dehydrogenation and CO₂ hydrogenation under mild conditions due to the synergistic effect from multiple components. Especially, the experimental and theoretical studies demonstrate that the application of W₁₈O₄₉ support with abundant oxygen vacancies enables a highly efficient hydrogen spillover effect, which facilitates the storage of dissociated hydrogen atoms and the desorption of adsorbates from active sites, thus accelerating the dehydrogenation and hydrogenation processes. These findings may provide a guideline for designing high-performance catalysts for hydrogen-involved reactions by exploiting hydrogen spillover effect.