Catalysis: Reactivity and Structure

High Activity of Ce_1-xNi_xO_2-y for H-2 Production through Ethanol Steam Reforming: Tuning Catalytic Performance through Metal-Oxide Interactions

The importance of the oxide: Ce_0.8Ni_0.2O_2−y is an excellent catalyst for ethanol steam reforming Metal–oxide interactions perturb the electronic properties of the small particles of metallic nickel present in the catalyst under the reaction conditions and thus suppress any methanation activity. The nickel embedded in ceria induces the formation of O vacancies, which facilitate cleavage of the OH bonds in ethanol and water. Ce_0.8Ni_0.2O_2−y is an excellent catalyst for ethanol steam reforming. It is less expensive than Rh/CeO₂ and has a higher catalytic activity. Under the reaction conditions, Ce_0.8Ni_0.2O_2−y contains small particles of nickel dispersed on partially reduced nickel-doped ceria. Metal–oxide interactions perturb the electronic properties of Ni and suppress its activity for methanation; at the same time, the nickel embedded in ceria induces the formation of O vacancies that facilitate the cleavage of the OH bonds in ethanol and water. These studies show the importance of both the metal and the oxide phase in catalysts for ethanol steam reforming. Both phases must be taken into consideration when trying to improve catalyst performance.

Ref: Zhou, G., Barrio, L., Agnoli, S., Senanayake, S.D., Evans, J., Kubacka, A., Estrella, M., Hanson, J.C., Martinez-Arias, A., Fernandez-Garcia, M., and Rodriguez, J.A. Angewandte Chemie-International Edition, 2010. 49(50): p. 9680-9684. DOI:10.1002/anie.201004966