from first principles PP-I-1

OP-III-28Mechanism of Low-Temperature Carbon Monoxide Oxidation overPdCl 2 -CuCl 2 /γ-Al 2 O 3 CatalystBruk L.G. 1 , Titov D.N. 1 , Zubavichus Ya.V. 2 , Tkachenko O.P. 3 , Ustyugov A.V. 1 ,Oshanina I.V. 1 , Veligzhanin A.A. 2 , Kustov L.M. 3 , Temkin O.N. 11 Lomonosov Moscow University of Fine Chemical Technology, Moscow, Russia2 National Research Center “Kurchatov Institute”, Moscow, Russia3 N.D. Zelinsky Istitute of Organic Chemistry Russian Academy of Sciences, Moscow, Russialgbruk@mail.ruThis report deals with new data on the state of active components on the surface of the PdCl 2 -CuCl 2 /γ-Al 2 O 3 catalyst and the mechanism of the low-temperature oxidation of carbonmonooxide. The structure of freshly prepared PdCl 2 -CuCl 2 /γ-Al 2 O 3 catalyst was studied byphysical metods (XAS, XRD, SEM, DRIFTS) [1]. It was shown that copper and palladiumexist on the surface of γ-Al 2 O 3 in the forms of crystalline of Cu 2 Cl(OH) 3 (paratacamite) andchemisorbed mononuclear PdCl 2- 4 anions, respectively. DRIFTS spectra indicate that bothlinear (2114 cm -1 ) and bridging (1990 and 1928 cm -1 ) coordinated carbon monooxide emergeupon CO adsorption on the catalyst surface.The kinetic regularities were studied at 18-40 o C and atmospheric pressure of CO, O 2 , N 2 ,H 2 O(gas) mixture in a flow reactor (steady state conditions). The activation energy of thereaction was found to be negative (-40 kJ/mole*K). The empirically derived equation for therate of carbon dioxide formation is presented below (1).r kP P P02 . 17 . 08 .CO2 CO H2O O2The high kinetic orders for water and oxygen partial pressures allowed us to proposemechanisms with the participation of both (O 2 and H 2 O) reagents in steps of carbon dioxideformation.Alternative mechanisms of this reaction are discussed.Acknowledgements. This work was supported by the Government of Moscow (Russia) andthe Russian Foundation for Basic research (project nos. 11-03-00118 and 11-03-00820) andstate contract no. 16.552.11.7003.(1)References[1] D.N. Titov, A.V. Ustyugov, O.P. Tkachenko, L.M. Kustov, Ya.V. Zubavichus, A.A. Veligzhanin,N.V. Sadovskaya, I.V. Oshanina, L.G. Bruk, O.N. Temkin, Kinet. Katal. 53(2) (2012) 272.72