Redox behavior of surface-modified CeO2-ZrO2 catalysts by chemical filing process

Surface modification of CeO2-ZrO2 solid solutions took place using formatio n and transport of volatile vapor complexes such as AlCl3-CeCl3 and AlCl3-Z rCl4, which was denoted as "chemical filing." XPS analysis showed surface C e enrichment, and transmission electron microscopy and Raman spectra reveal ed that a defective phase was formed on the surface of the samples by the c hemical filing. The reduction temperature of the samples after the chemical filing was about 50 K lower than that of the fresh sample and further decr eased by a reduction/reoxidation cycle. The redox property of the chemicall y filed sample was maintained even after the redox cycles at high temperatu res, indicating its excellent durability compared to the solid solution pre pared by a conventional procedure.