CO Oxidation on Ceria Studied by Electrochemical Impedance Spectroscopy

Shaping of Porous CeO2 Powders into Highly Active Catalyst Carriers

CeO₂ is attracting more and more attention because of its outstanding performance in heterogeneous catalysis, as an active support and a reaction promoter in reactions of industrial interest. We herein describe a novel and scalable manufacturing process of mm-sized CeO₂ spheres by a combination of extrusion and spheronization of CeO₂ porous powders. In this study, wet paste formulation and fabrication procedures were optimized, and as a result methylcellulose was identified as the best plasticizer for paste extrusion to provide well-defined spherical shapes and smooth surfaces, as well as reproducible batches. After nickel impregnation (10 wt %), the catalytic performance of CeO₂ supports was evaluated in the CO₂ methanation reaction (T = 250-350 °C, P = 5 bar·g) and compared with that of commercial Al₂O₃ spheres doped or not with CeO₂. These novel CeO₂-based catalysts are easily reduced at a moderate temperature and more active than the Al₂O₃ analogues, particularly at low reaction temperatures and small reactor volumes, properties that make their implementation in emerging reactor configurations very promising.