Kinetics of the Preferential Oxidation of CO over CuO/CeO2Catalysts in H2-Rich Gases

The influence of reaction parameters such as temperature, contact time, and O 2, CO, H 2, CO 2, and H 2 O partial pressures on the catalytic performances of 4 wt % CuO/CeO 2 in the CO-PROX process (the preferential oxidation of CO) has been investigated in a fixed-bed reactor. Catalyst appears very active (light-off at 70 °C) and selective; reaction kinetics is weakly depressed by CO 2 and H 2 O and not significantly increased with increasing O 2 concentration, while the reaction order in CO is variable with temperature ranging from values <1 up to 110 °C and >1 at higher temperatures. A power-law rate equation fitted the experimental data under typical CO-PROX conditions in order to evidence the lower activation energy of the catalytic oxidation of CO with respect to H 2 . A Langmuir−Hinshelwood type reaction rate is able to describe the catalytic behavior in the whole field of experimental conditions explored.