CO(2) Activation over Nanoshaped CeO(2) Decorated with Nickel for Low-Temperature Methane Dry Reforming

[Image: see text] Dry reforming of methane (DRM) is a promising way to convert methane and carbon dioxide into H(2) and CO (syngas). CeO(2) nanorods, nanocubes, and nanospheres were decorated with 1–4 wt % Ni. The materials were structurally characterized using TEM and in situ XANES/EXAFS. The CO(2) activation was analyzed by DFT and temperature-programmed techniques combined with MS-DRIFTS. Synthesized CeO(2) morphologies expose {111} and {100} terminating facets, varying the strength of the CO(2) interaction and redox properties, which influence the CO(2) activation. Temperature-programmed CO(2) DRIFTS analysis revealed that under hydrogen-lean conditions mono- and bidentate carbonates are hydrogenated to formate intermediates, which decompose to H(2)O and CO. In excess hydrogen, methane is the preferred reaction product. The CeO(2) cubes favor the formation of a polydentate carbonate species, which is an inert spectator during DRM at 500 °C. Polydentate covers a considerable fraction of ceria’s surface, resulting in less-abundant surface sites for CO(2) dissociation.