Spatial decoupling of CH4 oxidation and CO2 reduction enables near-stoichiometric dry reforming of methane

Abstract

The practical application of dry reforming of methane (DRM) is hindered by catalyst deactivation, primarily due to the deviation of the ideal 1 : 1 H₂ : CO stoichiometry for competitive CH₄ and CO₂ adsorption/activation. Excessive CH₄ decomposition results in H₂ : CO > 1 with carbon deposition, while predominant CO₂ chemisorption leads to H₂ : CO < 1 with the favorable reverse water-gas shift (RWGS) side reaction. Herein, we demonstrate an *O-migration coupling strategy on Pt/CeO₂ featuring Pt clusters and frustrated Lewis pairs (FLPs, consisting of two Ce³⁺ and one lattice oxygen) to achieve near-stoichiometric and durable DRM. The FLP sites on the CeO₂ support, independent of Pt–CeO₂ interfaces, reduce CO₂ to CO while generating *O species. These *O species migrate to Pt clusters, driving the partial CH₄ oxidation. Through this *O-migration-enabled spatial decoupling of CO₂ reduction and CH₄ oxidation, the catalyst delivers a near-stoichiometric H₂ : CO ratio of 0.99 and an unprecedented CH₄ conversion rate of 93.9 mol g_Pt⁻¹ h⁻¹ at 700 °C. Moreover, stable performance is exhibited for over 400 h, with a turnover number exceeding 7 200 000. This work establishes oxygen migration coupling as a potential strategy for spatially decoupled redox catalysis beyond DRM.