Kinetics of Carbon Monoxide Oxidation over CuO Supported on Nanosized CeO2

A CuO/CeO2 catalyst prepared by incipient wetness impregnation (7 wt % Cu) with well-dispersed CuO on nanosized ceria, has been used to obtain a kinetic expression for CO oxidation, including estimation of kinetic parameters, in the absence of CO2, H2O, or H-2 in the feed stream. Experimental data were checked to be collected in the kinetic regime, in the absence of external and intraparticle mass and heat transfer, and in a wide range of experimental conditions-with CO partial pressure ranging from 0.0015 to 0.0125 atm (that is, including those usually found in PROX reactors) and A values between 0.35 and 13.3- and were fitted to different rate expressions (power-law and mechanistic) by using a genetic algorithm. Although a power-law rate equation satisfactorily fits the experimental data, it is limited to the experimental range of operation conditions. Further discrimination among mechanistic models indicates that an expression proposed by Liu and Flytzani-Stephanopoulos (Chem. Eng. J. 1996, 64, 283), with a partial reaction order of 0.08 with respect to oxygen, is the most statistically significant, almost indistinguishable from the expression proposed by Mars-Van Krevelen (Spec. Suppl. Chem. Eng. Sci. 1954, 3, 41).