NO reduction, CO and hydrocarbon oxidation over combustion\ud synthesized {Ag/CeO_2} catalyst

The combustion technique produces ionically dispersed Ag on a nano-crystalline {CeO_2} surface. The catalysts thus produced were characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Catalytic properties towards NO reduction, CO and hydrocarbon oxidation have been investigated using the temperature programmed reaction technique in a packed bed tubular reactor. These results are compared with \alpha-{Al_2O_3} supported finely divided Ag metal particles synthesized by the same method. Both oxidation and reduction reactions over {Ag/CeO_2} have been observed to occur at lower temperatures compared to {Ag/Al_2O_3}. The rate and turnover frequency of the NO+CO reaction over 1% {Ag/CeO_2} are 56.3 \mu mol {g^-1 s^-1} and {0.97 s^-1} at {225^0}C respectively. Activation energy {(E_a)} values are 71 and 67 kJ {mol^-1} for {CO+O_2} and NO+CO reactions, respectively, over 1% {Ag/CeO_2} catalyst