Performance of La 1− xCe xFe 0.7Ni 0.3O 3 perovskite catalysts for methane steam reforming

Abstract

La 1− x Ce x Fe 0.7Ni 0.3O 3 perovskite catalysts, denoted as LCFN- x (0.1 ≤ x ≤ 0.5), were prepared using a Pechini method. The effects of Ce-substitution and calcination temperature on the structure and performance of the prepared catalysts during the steam reforming of methane (SRM) were investigated. The XRD patterns of these catalysts indicated that a well-crystallized perovskite structure was formed when LFN and LCFN were calcined at temperatures higher than 500 and 600 °C, respectively. For the reaction system investigated in this study, the most suitable calcination temperature was 700 °C. The 700 °C-calcined catalysts, denoted as LFN-700 and LCFN-700, exhibited the highest methane conversion among catalysts of the same type, due to their relatively large surface area and small crystallite size compared with those of perovskite catalysts. The catalytic activity increased with the amounts of added Ce, up to x = 0.2–0.3, but decreased significantly when x ≥ 0.5. In particular, LCFN-0.2 exhibited a higher hydrogen yield and slower deactivation rates than those exhibited by a commercial catalyst at the steam/carbon ratio of 1. This result was obtained because coke deposition was retarded to a greater extent on LCFN-0.2 than on the commercial catalyst under the selected reaction conditions.