Redox Behavior of Surface-Modified CeO2−ZrO2 Catalysts by Chemical Filing Process

• Published in: Chemistry of materials Vol. 12; no. 3; pp. 643 - 649
• Main Authors: Ozaki, Tetsuya, Masui, Toshiyuki, Machida, Ken-ichi, Adachi, Gin-ya, Sakata, Takao, Mori, Hirotaro
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 20.03.2000
• Subjects: Catalysis; Catalysts: preparations and properties; Chemistry; Exact sciences and technology; General and physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Mixed catalyst; Cerium Chlorides; Cerium Oxides; Transition metal Compounds; X ray; Solid solution; Zirconium Chlorides; Heterogeneous catalysis; Aluminium Chlorides; Preparation; Photoelectron spectrometry; Zirconium Oxides; Lanthanide Compounds
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm9903374

Surface modification of CeO2−ZrO2 solid solutions took place using formation and transport of volatile vapor complexes such as AlCl3−CeCl3 and AlCl3−ZrCl4, which was denoted as “chemical filing.” XPS analysis showed surface Ce enrichment, and transmission electron microscopy and Raman spectra revealed that a defective phase was formed on the surface of the samples by the chemical filing. The reduction temperature of the samples after the chemical filing was about 50 K lower than that of the fresh sample and further decreased by a reduction/reoxidation cycle. The redox property of the chemically filed sample was maintained even after the redox cycles at high temperatures, indicating its excellent durability compared to the solid solution prepared by a conventional procedure.