Catalytic Properties And Structure Of CeO₂ And Ce_0.5Zr_0.5O₂-Supported CuO Or PdO Catalysts

Volatile organic compounds (VOCs) and CO are recognized as major contributors to air pollution. Major VOCs emission sources are vehicles (car and trucks), and various industrial sites, such as plants manufacturing organic chemicals, polymers, or synthetic fibers, etc. The USA Clean Air Act of 1990 calls for a 90% reduction in emission of 189 toxic chemicals, 70% of them VOCs, over the next nine years. Catalytic combustion is one of the most important processes for VOCs destruction, since VOCs oxidation over a catalyst takes place at temperature much lower than those required for thermal destruction. Combustion catalyst has been extensively studied all over the world during the past decades. Advances in catalyst development, however, are continuing, but additional research is needed to improve catalytic active and to understand the reaction mechanism.Cerium oxide has been widely used in the automotive three-way catalytic converter as an oxygen storage medium and thermal stabilizer. The interaction of CeO₂ with precious metal (Pt and Rh) has been intensively studied. By contract, little information is available to date on the interaction of CeO₂ and CeO₂-containing oxides with CuO or PdO catalysts and their function to complete oxidation of carbon monoxide and methane. However, less is known about active site and reaction mechanism of CO and methane oxidation.In this work, we have developed a series of novel catalysts, such as CuO/CeO₂, PdO/CeO₂ and PdO/Ce_0.5Zr_0.5O₂, which show high activity at low temperature. At the same time, bulk composition, oxygen species, CO adsorbed species and redox behaviour over these...