Relationship between hydrothermal temperatures and structural properties of CeO(2) and enhanced catalytic activity of propene/toluene/CO oxidation by Au/CeO(2) catalysts

A simple hydrothermal synthesis of CeO(2) was implemented to obtain a series of CeO(2)-supported gold (Au) catalysts, used for the total oxidation of propene/toluene/CO gas mixtures and the oxidation of CO. CeO(2) preparation started from a cerium hydrogen carbonate precursor using a range of different hydrothermal temperatures (HT) from 120 to 180°C. High-resolution transmission electron microscopy, X-ray diffraction, and H(2)-temperature-programmed reduction data indicated that CeO(2) morphology varied with the HT, and was composed of the more active (200) surface. Following Au deposition onto the CeO(2) support, this active crystal plane resulted in the most widely dispersed Au nanoparticles on the CeO(2) support. The catalytic performance of the CeO(2)-supported Au catalysts for both oxidation reactions improved as the reducibility increased to generate lattice oxygen vacancies and the number of adsorbed peroxide species on the CeO(2) support increased due to addition of Au. The Au catalyst on the CeO(2) support prepared at 120°C was the most active in both propene/toluene/CO oxidation and independent CO oxidation.