J. Ogonowski, E. Skrzynska REVERSE WATER GAS SHIFT REACTION - THE THERMODYNAMIC ANALYSIS AND EXPERIMENTAL DATA FOR VMGOX CATALYSTS (Institute of Organic Chemistry and Technology, Cracow University of Technology) The results in thermodynamic analysis of the reverse water gas shift reaction were compared with the experimental data. <...> Changes of the carbon dioxide conversion during the reaction time were monitored chromatographically% while an alterations of physicochemicai properties of vanadium-magnesium oxide catalysts were investigated using titrimetric and temperatureprogrammed reduction analysis. <...> Processes of catalytic dehydrogenation of hydrocarbons in the presence of carbon dioxide have been intensively studied recently [1]. <...> It is known, that introduction of an oxidizing agent into the reaction zone allows to omit the thermodynamical limitations of the equilibrium process in the inert gas atmosphere (eq.l). <...> Moreover, deep oxidation of hydrocarbons, typical for the dehydrogenation reaction with dioxygen, does not proceed [1-3]. <...> In the one-step pathway (eq. 2) carbon dioxide acts as a reoxidant of the catalyst surface, reduced by a hydrocarbon. <...> In the two-step pathway carbon dioxide reacts with hydrogen (eq. 3) and shifts the alkane equilibrium dehydrogenation (eq. 1). <...> CnH2n+2 CnH2n+2 + CO2 H2 + CO2 CnH2n + H2 CO + H2O CnH2n +CO + H2O In our previous works we presented thermodynamic analysis of isobutane dehydrogenation reaction in the presence or absence of carbon dioxide [3]. <...> In both cases, the equilibrium conversion of isobutane was highest for two-step reaction model. <...> Therefore, the catalyst active in the reverse water gas shift reaction (eq. 3) should improve the conversion of isobutane. <...> This paper continues our previous study and consists of thermodynamic analysis of RWGS reaction for different initial conditions. <...> The reverse water gas shift reaction was carried out over several vanadium-magnesium oxide catalysts active in the isobutane dehydrogenation reaction [5]. <...> The additional analysis (i.e., titration and temperature-programmed reduction) allowed to observe the changes in the physicochemical properties of VMgOx catalysts after RWGS and to clarify which forms of vanadium are active in the process. 48 EXPERIMENTAL Vanadium-magnesium oxide catalysts were synthesized in such a way as to give V/Mg molar ratio of 0.11 (20 wt% of V2O5 after calcination in static air for 6 h <...>