Improved Activity of Ru/CeO₂ Catalyst for CO₂ Methanation by Enhanced Electronic Metal–Support Interaction

The Ru-based catalyst for CO2 methanation has drawn increasing attention. In this work, plasma decomposition of the precursor of the Ru/CeO2 catalyst was conducted at atmospheric pressure and approximately 150 °C, followed by thermal hydrogen reduction at 200 °C. The obtained catalyst possesses more basic sites and oxygen vacancies, which promote the adsorption and activation of CO2. A high Ru dispersion is also achieved with a charge transfer from oxygen vacancy to dispersed Ru nanoparticles, causing enhanced electronic metal–support interaction and an active Ru/CeO2 interface. The dissociative adsorption of H2 is thus accelerated. The formate and CO pathways are all promoted for CO2 methanation. An improved low-temperature performance for the methanation of CO2 was thereby attained. For example, a CO2 conversion of 85.2% with a methane selectivity of 99.0% was achieved on the plasma decomposed catalyst at 300 °C with a feed gas of CO2/H2/N2 of 16/64/20 at 60,000 mL·gcat–1·h–1.