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 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 (FLP, 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 gPt-1 h-1 at 700 °C. Moreover, stable performance is maintained 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.