Structural Dynamic Evolution of Pt Nanoclusters in Ultra-Low-Temperature Methane Combustion with Nitrous Oxide

Tailoring and stabilizing the active sites of supported noble-metal catalysts to a semioxidized state with unsaturated coordination remain a long-standing challenge in heterogeneous catalysis. Herein, we develop a reaction-atmosphere-driven evolution approach for dynamic structural tuning of semioxidized metal sites in supported Pt catalysts. N 2 O as an alternative oxidant is used over Pt/TiO 2 in CH 4 combustion to dynamically prompt the transformation of Pt 0 nanoclusters into Pt δ+ (0 < δ < 2) nanoclusters. Compared to CH 4 combustion with O 2 that inclines to overoxidize Pt 0, the catalytic activity of CH 4 –N 2 O combustion is distinctly boosted, achieving complete CH 4 combustion at only 200 °C, outperforming the state-of-the-art catalysts using O 2 as the oxidant. Computational and experimental studies validate that N 2 O triggers less electron transfer from Pt than from O 2, thereby facilitating the formation and preservation of Pt δ+ species during CH 4 combustion. The newly emerged semioxidized Pt δ+ species with oxygen-deficient coordination structures simultaneously enhance lattice oxygen activation and the first C–H bond dissociation of CH 4, contributing to ultralow temperature activity. Our work demonstrates that modulating the reaction atmosphere to achieve the structural dynamic evolution of semioxidized metal sites can provide new strategies for designing highly efficient catalysts for low-temperature CH 4 combustion.