OP-II-3

PP-II-36INFLUENCE OF INTERNAL DIFFUSION ON CO PREFERENTIALOXIDATION OVER Cu/CeO 2-x CATALYSTSPotemkin D.I. 1,2 , Snytnikov P.V. 1,2 , Sobyanin V.A. 1,21 Boreskov Institute of Catalysis SB RAS, Pr. Lavrentieva, 5,Novosibirsk, 630090, Russia2 Novosibirsk State University, Pirogova St., 2, Novosibirsk, 630090, Russiapotema@catalysis.ruPreferential CO oxidation (CO PrOx) is a well known method for CO removal fromhydrogen-rich gas mixtures. Wall coated catalytic microchannel reactors arefavorable candidates for CO PrOx due to high heat and mass transfer rates achieved[1]. The present work aims at a systematic study of the preferential CO oxidation inhydrogen-rich gas mixtures over copper-cerium oxide catalyst in a microchannelreactor, in the presence of CO 2 and H 2 O, to optimize washcoating procedure andreaction conditions to reach CO concentrations below 10 ppm.Several series of copper-ceria catalysts for preferential CO oxidation weresynthesized by various methods that allowed variation of the textural andmorphological characteristics of the samples. The 5 wt.% copper catalyst preparedby impregnation showed the optimal catalytic performance and was deposited intothe reactor’s microchannels. The obtained samples demonstrated good impactresistance,and survived contacts with water.Catalytic performance of the washcoated catalyst in the microchannel reactorwere checked using model feeds at WHSV = 50 ÷ 500 L g –1 h –1100 ÷ 300°С (Fig.1).and temperatureIt was observed that the reactions of CO and H 2 oxidation under wide range ofreaction conditions proceeded independently using the same common reagent – O 2 .This assumption helps to simplify the mathematical modeling and describe theobserved kinetic dependencies by relatively simple equations. For both CO and H 2oxidation reactions, power-law reaction rate equations were proposed to describe thereaction kinetics. The apparent activation energy of the both reactions and thereaction orders with respect to O 2 and CO have been determined.Using the obtained rate expressions for CO and H 2 oxidation reactions, theeffectiveness factors (η) for CO (Fig. 2) and H 2 oxidation reactions were calculated.The effectiveness factor for H 2 oxidation is equal to 1 in wide range of temperaturesand coating thicknesses, because of the zero reaction order with respect to O 2 . It can398