Obtaining hydrogen by steam reforming of residual glycerol from biodiesel production using Ni/La2O3-CeO2 catalysts

Abstract

Ni/La2O3-CeO2 catalysts derived from perovskite-type precursors, with La1−xCexNiO3 composition (x = 0, 0.1, and 0.2), were prepared by the precipitation method, without and with the use of Pluronic F-127 surfactant. The materials were characterized using techniques including thermogravimetric analysis, nitrogen physisorption, scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and temperature programmed reduction with H2. The presence of Ce and use of the surfactant resulted in samples with smaller NiO crystallites and lower reduction temperature, with the catalysts A2 (La0.9Ce0.1NiO3 + P) and A6 (LaNiO3 + P) showing the highest percentages of the LaNiO3 phase, according to XRD and TPR analyses. The glycerol conversions were high (above 96%) and similar for all the catalysts, except A5 (LaNiO3). Although the samples prepared with Ce addition did not show the best selectivity towards H2, their use led to lower carbon formation during the reaction (%C = 2.2), compared to the sample with the best catalytic performance (%C = 8.0). Overall, the materials studied here were stable and active during 5 h of reaction, with low coke formation in all cases. The findings indicated that perovskite-type catalysts synthesized with the addition of surfactant are promising for application in the steam reforming of glycerol for hydrogen production.