Engineering a Nickel–Oxygen Vacancy Interface for Enhanced Dry Reforming of Methane: A Promoted Effect of CeO2 Introduction into Ni/MgO

Nickel, the most commonly used active metal for the dry reforming of methane (DRM), often encounters the challenge of severe deactivation due to sintering and carbon deposition. In this study, we introduce cerium into Ni/MgO, a traditional catalyst for DRM, to improve its activity and stability, resulting in an enhanced Ni/MgCeOx catalyst. With the optimized doping amount of cerium (Ce/Mg = 0.12), the catalyst demonstrates a conversion rate 65% for CH4, 75% for CO2, and a H2/CO ratio of 0.76, while the Ni/MgO catalyst only achieves a conversion rate of 57% for CH4, 65% for CO2, and a H2/CO ratio of 0.68. Furthermore, the introduction of cerium significantly improves the stability of the catalyst. These improved activity and stability can be attributed to the easy reducibility of NiOx species, small Ni particle size, and abundant oxygen vacancies resulting from the doping of cerium. The affinity between CeO2 and NiOx inhibits the formation of the NiO-MgO solid solution, which contributes to the enhanced performance.