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

Abstract

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 CO ₂ -reforming of methane has been studied for TiO ₂ -supported Ni catalyst. Reduction at 773 K resulted in a larger rate constant for the CH ₄ –CO ₂ 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 CO ₂ was not affected by the reduction temperature, while that for the dissociation of CH ₄ 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 CH ₄ –CO ₂ reaction by reducing the catalyst at a higher temperature, suggesting that the activation of CH ₄ rather than of CO ₂ is primarily responsible for the higher activity in the SMSI state.