Rh/CexZr1-xO2 as NGV Catalyst: Impact of the Preparation of Ceria-Zirconia Support on the Catalytic Performance

Methane oxidation has been studied on Rh/CexZr1-xO2. Catalytic performances were found highly sensitive to the preparation method of CexZr1-xO2 support. Coprecipitation method leads to the highest conversion and the lowest activation barrier suggesting improved metal-support interaction. In contrast, weak resistance to thermal aging is observed. Finally aged coprecipitated Rh/CexZr1-xO2 mimics the kinetic behavior of catalysts prepared by crystal templating method. Kinetic measurements performed on this latter catalyst show that a single site reaction mechanism is more appropriate compared to dual site mechanism which agrees with the assumption that deactivation of coprecipitated samples would be related to the suppression of the metal-support interface.

Automated summary

Methane oxidation was studied on Rh/CexZr1-xO2 catalysts, and the preparation method of CexZr1-xO2 support was found to significantly affect catalytic performance. Catalysts prepared by coprecipitation method showed the best performance with the highest conversion and the lowest activation barrier, but weak resistance to thermal aging. Aged coprecipitated catalysts mimicked the kinetic behavior of catalysts prepared by crystal templating method, indicating the involvement of a single site reaction mechanism.