?Estudio micro-cinético de la reacción de gas de agua reversa (RWGS) sobre Cu/ZrO y Ga O /Cu/ZrO .? (ID 162)

MIGUEL ANGEL BALTANAS; E.L. FORNERO; A.L. BONIVARDI

Cordoba

Congreso; XX Congreso Argentino de Catalisis; 2017

Sociedad Argentina de Catalisis

The performance of two copper-based catalysts, Cu/ZrO2 and Ga2O3/Cu/ZrO2, in regards the reverse water gas shift (RWGS) reaction as compared with their reaction rates for the methanol synthesis reaction (RCH3OH) was studied using H2/CO2 mixtures at 1.6 and 0.1 MPa, at 498 K. The reactivity studies were carried out using a Carberry-type microcatalytic reactor operated in the batch (transient) mode after H2 prereduction at 523 K (2 h).Measurements of the catalytic activity were also made using D2/CO2 mixtures (0.1 MPa, 498 K) to assess isotope effects. For Cu/ZrO2, the initial RWGS reaction rate using D2 instead of H2 was slightly higher whereas such rate was about equal for the ternary catalyst.Kinetic rate expressions obtained from the Langmuir-Hinshelwood-Hougen-Watson formalism were used to model and analyze the experimental results and the reaction mechanism(s) of the RWGS on these catalysts.Congruence was found between the experimental results and a reaction mechanism where (predominantly) CO2 adsorbs dissociatively on the Cu particles (rate-determining step). The reduction of (ad)oxygen and surface hydroxyls follow afterwards.