Studies on Cu/CeO2: A New NO Reduction Catalyst

• Published in: Journal of catalysis Vol. 186; no. 1; pp. 36 - 44
• Main Authors: Bera, Parthasarathi, Aruna, S.T., Patil, K.C., Hegde, M.S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 15-08-1999; Elsevier
• 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; NH3; Cu/CeO2; CO; NO reduction; hydrocarbon; combustion synthesis; Mixed catalyst; Cerium Oxides; Binary compound; Catalytic reaction; Hydrocarbon; EPR spectrometry; Transition metal; X ray; Experimental study; X ray diffraction; Chemical reduction; Ammonia; Heterogeneous catalysis; Transmission electron microscopy; Nitric oxide; Photoelectron spectrometry; Lanthanide Compounds; Carbon monoxide; Copper
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1006/jcat.1999.2532

Fine particle and large surface area Cu/CeO2 catalysts of crystallite sizes in the range of 100–200 Å synthesized by the solution combustion method have been investigated for NO reduction. Five percent Cu/CeO2 catalyst shows nearly 100% conversion of NO by NH3 below 300°C, whereas pure ceria and Zr, Y, and Ca doped ceria show 85–95% NO conversion above 600°C. Similarly NO reduction by CO has been observed over 5% Cu/CeO2 with nearly 100% conversion below 300°C. Hydrocarbon (n-butane) oxidation by NO to CO2, N2, and H2O has also been demonstrated over this catalyst below 350°C making Cu/CeO2 a new NO reduction catalyst in the low temperature window of 150–350°C. Kinetics of NO reduction over 5% Cu/CeO2 have also been investigated. The rate constants are in the range of 1.4×104 to 2.3×104 cm3 g−1 s−1 between 170 and 300°C. Cu/CeO2 catalysts are characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and electron paramagnetic resonance spectroscopy where Cu2+ ions are shown to be dispersed on the CeO2 surface.