Rh/MgO/Ce0.5Zr0.5O2 supported catalyst for autothermal reforming of methane: The effects of ceria–zirconia doping

The supported Rh/MgO/Ce0.5Zr0.5O2 catalysts were developed for autothermal reforming of methane. The effects of ceria–zirconia addition on the Rh catalyst were characterized with BET, XRD, SAED, HREM and TPR. The catalytic performance was evaluated on a flow through reactor. Results showed that the addition of ceria–zirconia enhanced the catalyst stability due to the interactions between ceria–zirconia, MgO promoter and the active component Rh. Meanwhile, the selectivity towards hydrogen in reformate was also boosted because of the increased water gas shift activity by the mixed oxides. The results also showed that the structural properties, the textural properties and the redox properties of ceria–zirconia had great influences on the catalyst performance, especially on the catalyst stability. Formations of single phase solid solution, larger pore size as well as Ce/Zr ratio at 1/1 were more desirable for ceria–zirconia dopant. As a result, one of the optimized honeycomb catalysts with the composition of 0.3% Rh/2.5% MgO/43.2% Ce0.5Zr0.5O2/54.0% cordierite (wt.%) has been continually operated at 800 °C up to 2000 h without deactivation.