Unlocking the Role of C Doping in a RuO₂ Matrix in CO₂ Methanation from a Combined Theoretical and Experimental Approach

A new type of ruthenium-based catalyst, labeled RuOxCy@C, consisting of a combination of metallic ruthenium (Ru0), ruthenium oxide (RuO2), and a ruthenium oxycarbonate phase (RuO2Cy) formed by interstitial carbon doped into RuO2, has been recently reported for low-temperature CO2 methanation. Its catalytic activity and long-term stability depend on two competing processes that take place under reaction conditions: RuO2 reduction with H2 to form inactive Ru0 nanoparticles, and C diffusion into RuO2 to form the active oxycarbonate phase. A combination of experimental and computational techniques is applied in this work to investigate the relative rate of both processes in order to identify possible modifications in the catalyst composition that might improve the overall catalytic performance.