Effect of reduction temperature on the CO2-reforming of methane over TiO2-supported Ni catalyst

On the basis of the rate constant per active site determined by pulse surface reaction rate analysis (PSRA), the effect of reduction temperature on the CO2-reforming of methane has been studied for TiO2-supported Ni catalyst. Reduction at 773 K resulted in a larger rate constant for the CH4-CO2 reaction than that at 673 K. Since the amount of CO adsorbed on the catalyst decreased with an increase in the reduction temperature, the phenomenon could be understood as a result of the strong metal-support interaction (SMSI). The ability of the catalyst to dissociate CO2 was not affected by the reduction temperature, while that for the dissociation of CH4 was enhanced by increasing the reduction temperature on a per active site of catalyst basis. A higher specific activity was obtained also for the steady-state CH4-CO2 reaction by reducing the catalyst at a higher temperature, suggesting that the activation of CH4 rather than of CO2 is primarily responsible for the higher activity in the SMSI state.