Ni supported on La2O3-SiO2 used to catalyze glycerol steam reforming

Ni catalysts supported on La2O3-SiO2 were tested in the steam reforming of glycerol. The catalysts were prepared by the wet impregnation method and characterized by energy dispersive X-ray spectroscopy (EDX), nitrogen physisorption (BET method), X-ray diffraction (XRD), temperature programmed reduction with H-2 (TPR) and in situ XRD. XRD and TPR analysis indicated several Ni species in the samples: NiO, LaNiO3 and La2NiO4. From the analyses of XRD and in situ XRD data it was also possible to estimate the sizes of the NiO and Ni-0 crystallites, respectively, which suggested a greater or lesser degree of dispersion of these species on the various supports. The catalytic tests were performed in a fixed bed reactor containing 150 mg catalyst at 600 degrees C, with an inlet water: glycerol ratio of 3:1. These tests showed that, the deposition of carbon on the catalyst during the reaction fell steadily as the proportion of La2O3 in the support increased. This may be related to the formation of La carbonate as the CO2 is adsorbed on La2O3 on the support. (C) 2012 Elsevier Ltd. All rights reserved.