Steam and CO2 reforming of ethanol over Rh/CeO2 catalyst

• Published in: Applied catalysis. B, Environmental Environmental, 2011-02, Vol.102 (1-2), p.94-109
• Main Authors: da Silva, Adriana M., de Souza, Kátia R., Jacobs, Gary, Graham, Uschi M., Davis, Burtron H., Mattos, Lisiane V., Noronha, Fábio B.
• Format: Article
• Language: English
• Subjects: Carbon formation; Catalysis; Chemistry; CO2 reforming of ethanol; Exact sciences and technology; General and physical chemistry; Hydrogen production; Rh/CeO2 catalyst; Steam reforming of ethanol; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2010.11.030

[Display omitted] ▶ Rh/CeO2 high surface area catalyst exhibited better stability in SR of ethanol, with no carbon formation. ▶ DRIFTS experiments revealed that Rh carbonyl bands were quite s, showing no carbon deposits. ▶ Improved stability is likely attributed to a greater fugacity of available O from the support. ▶ O adatoms or surface OH groups from the support takes part on the carbon removal mechanism. The performance of ceria supported Rh catalysts prepared with high and low surface areas for steam reforming and dry reforming of ethanol was investigated. According to results of diffuse reflectance infrared Fourier transform spectroscopy of both reactions, dissociative adsorption of ethanol over ceria gives rise to ethoxy species and bridging OH groups. Oxidation of ethoxy species proceeds by addition of O provided by the support from species such as Type II bridging OH groups (i.e., steam reforming) or O adatoms (e.g., CO2 reforming). Rh promotes demethanation of acetate to carbonate and the steam/dry reforming of CHx species. Catalyst deactivation occurs from the deposition of carbon on the catalysts during both reactions. However, no carbon formation is observed on the Rh/CeO2 high surface area catalyst during steam reforming due to a higher surface fugacity of O from species adsorbed on the support that react to remove carbon.