Synergistic Catalysis of Atomically Dispersed CoO <i> _x </i> Species and Pt Nanoclusters for Efficient Hydrogen Isotope Oxidation

Catalytic oxidation is commonly employed in industry to reduce the concentration of tritium-containing radioactive gases leaked into the atmosphere, thereby protecting human health and the environment. Currently, Pt-based catalysts are considered promising candidates for the oxidative removal of tritiated gases. However, previously reported catalysts exhibit high activation barriers (≈1.0 eV) for the rate-determining step, which limits their overall efficiency. In this study, synergistic catalytic sites composed of Pt nanoclusters and atomically dispersed CoO_x species are strategically constructed within silicalite-1 zeolite, enabling efficient catalytic oxidation of hydrogen isotopes under low-temperature and high space velocity conditions. This improvement is primarily attributed to the dual functionality of the CoO_x unit, which not only serves as an oxygen donor but also modulates the electronic structure of adjacent Pt atoms. These effects facilitate both reaction pathways, lowering the energy barriers of their respective rate-determining steps to 0.63 and 0.92 eV, both well below 1.0 eV. The synthesized CoO_x/Pt@S-1 catalyst achieves >99% conversion of H₂ and D₂ at 40 °C under a GHSV of 48,000 mL g^-1 h^-1. Moreover, it demonstrates excellent stability over a 37 d intermittent restart test.