On the mechanism of visible-light accelerated methane dry reforming reaction over Ni/CeO2−x catalysts

The methane dry reforming reaction (DRM) converts and CO2 into syngas, a mixture of H2 CO. When illuminated by 790 mW cm−2 white light, the 2Ni/CeO2−x catalyst CH4 beyond thermodynamic equilibrium, while energy efficiency reaches 33%. DRM is sustained in purely photocatalytic mode without external heating, yielding rates 0.21 0.75 mmol (gcat • min)−1, respectively. Theoretical analysis Ni/CeO2−x optical properties agrees with in-situ UV-Vis DRS results reveals partly reduced Ce3+ sites crucial for extending absorption visible light range. Two mechanisms are postulated to occur: hot charge-carrier driven mechanism near-field induced resonant transfer, depending on photons used stimulate catalyst. This work identifies sub-stoichiometric as highly efficient boosting activation under mild conditions.