Reforming of CH4 with CO2 on Pt-supported catalysts: Effect of the support on the catalytic behaviour

This paper reports a study about the behaviour of different Pt-based catalysts supported on Al2O3, Na–Al2O3, K–Al2O3 and ZrO2 in methane reforming with CO2. Results indicate that Pt/Na (0.3 wt%)-Al2O3 and Pt/ZrO2 catalysts show both a good activity and selectivity with a very high catalytic stability at 1073 K. The Pt/K (0.3 wt%)-Al2O3 catalyst showed a good performance but a slightly lower conversion level than Pt/Na (0.3 wt%)-Al2O3. On the other hand, the Pt/Al2O3 catalyst displayed an important decrease of the methane conversion through the reaction time at 1073 K and hence, a lower catalytic stability due mainly to the carbon deposition. It can be concluded that either Na or K addition to Pt/Al2O3 enhances the catalytic stability since they provide basic sites, which favour the dissociation reaction of CO2 into CO and O. The O species can react with the carbon deposited on the Pt, thus cleaning the metallic phase of the doped catalysts.