Reaction of CH4 with CO2 and H2O over supported Ir catalyst

The CO2 reforming, steam reforming and simultaneous steam and CO2 reforming of CH4 have been investigated at 700-773 and at 1123 K on supported Ir catalysts in a fixed-bed continuous-flow reactor. In addition, the dissociation of CO2, the low temperature interaction of CO2 with CH4, and the effects of supports have been also examined. The dissociation of CO2, detected by infrared spectroscopy, is greatly promoted by the presence of CH4. The reaction between CO2 and CH4 occurred rapidly above 673 K to give CO and H-2 with ratio of 1.0-3.7. The highest specific activity was measured for Ir/TiO2. In the presence of H2O, H-2 was the dominant reaction product due to the water gas shift reaction. Using a stoichiometric gas mixtures, carbon deposition was very limited in all the three reactions. Kinetic parameters of the reaction were determined and a possible reaction mechanism is proposed.