Highly Active Ni/Xna/CeO2 Catalyst for Water-Gas Shift Reaction: Effect of Sodium on Methane Suppression

At low Na loadings, Na⁺ was incorporated into the CeO₂ lattice, activating the lattice O₂, and increasing the reducibility of the catalyst. By in-situ DRIFTS, methanation was found to be inhibited by the interaction between Na and Ni, leading to the absence of subcarbonyl species which are responsible for methanation.