Y-Doping Modulated Polyfunctional Interface for Side-Reaction-Free Dry Reforming of Methane

Dry reforming of methane (DRM) offers an attractive route for the coconversion of greenhouse gases (GHGs, CH4, and CO2) into syngas. However, thermo-catalytic processes require high temperatures and suffer from a low H2/CO ratio and coke-induced instability. Herein, we engineer the local environment of a supported Co cluster catalyst by incorporating yttrium (Y) into the CeO2 lattice (Co/CexY1–xO2, x = 1, 0.9, 0.8, 0.5, and 0). Strategic Y-doping (x = 0.8) compresses the lattice and forms a Co/Ce0.8Y0.2O2 catalyst, which generates a high concentration of oxygen vacancies, increases Co2+ content, and enhances the electronic interaction between Co and Ce0.8Y0.2O2. The triple synergistic effect creates an abundance of active Co2+–Ov–Ce3+ interfacial sites. Specifically, this optimized Co/Ce0.8Y0.2O2 catalyst drives the DRM reaction to near thermodynamic equilibrium at 650–750 °C (H2/CO ≈ 0.86), while exhibiting high resistance to coking for over 100 h and complete activity recovery upon thermal cycling. Density functional theory (DFT) calculation results indicate that the Co2+–Ov–Ce3+ interfacial sites enable delayed CH4 dissociation, promote CO2 activation, accelerate the removal of deposited carbon, and suppress the formation of RWGS-related intermediates. This work demonstrates an effective metal–Ov–support interface-engineering strategy for achieving kinetically synchronized and thermodynamically efficient DRM, providing a mechanistic foundation for the design of stable and side-reaction-free multicomponent catalytic systems.