Enhancing carbon dioxide conversion in methane dry reforming multistep reactions through transformation of active species on catalyst surface

Abstract

This study employed a novel one-pot method to encapsulate cerium species on the Ni–Al heterogeneous interface, aiming to achieve the capture and efficient utilization of greenhouse gas (CO2). Characterization results revealed that nickel species experienced various forms such as oxides and carbon-nickel compounds at the heterogeneous interface. The presence of cerium groups within the catalytic system induces the precipitation of nickel grain monomers on the support, decomposing the CH4–CO2 reforming process into a multistep reaction that breaks the thermodynamic barrier and kinetic limitation of the multicarbon coupling phenomenon, and greatly reduces the energy consumption of the reaction. Results showed that at a temperature of 800 °C and a Ni/Ce molar ratio of 0.2 in the catalyst, the activity was stable and the CO2 conversion reached 81.69 %, which was a 15.33 % enhancement compared to the base catalyst. Additionally, the mutual conversion of Ce3+/Ce4+ promoted the internal electron interaction process in the catalytic system, increasing the number of oxygen vacancies and reducing acidic sites, which facilitated reactant activation and carbon elimination. This work provides insights for the efficient utilization of greenhouse gases.