Discovery of a Robust Ru ₁ –O–Ce Single Atom Catalyst for Coke-Free Dry Reforming of Methane

Dry reforming of methane (DRM) represents a key route for CO2 utilization and methane valorization, yet catalyst coking and sintering under harsh conditions limits its large-scale application. Here, we discover a single-atom catalyst featuring Ru1–O–Ce sites that operates stably for DRM over 600 h at 40–225 L gcat–1 h–1 without detectable coking. Further anchoring Ru1–O–Ce sites on commercial particulate Al2O3 enables 2000-h catalytic stability at 750 °C, with CH4/CO2 conversions approaching thermodynamic equilibrium. Mechanistic studies reveal that Ru1–O–Ce sites partially dissociate methane at Ru1, and CHx species react with nearby O atoms to form CHxO intermediates; CO2 is efficiently activated at formed oxygen vacancies to restore Ru1–O–Ce sites. This bifunctional behavior aligns CH4 and CO2 activation, ensuring coke-free DRM progression and opening new avenues for designing stable, effective single-atom catalysts for methane reforming.