Increase of Ceria Redox Ability by Lanthanum Addition on Ni Based Catalysts for Hydrogen Production

The effects of lanthanum addition in Ni/CeO2 catalysts were investigated. The influence of synthetic procedures, namely, impregnation or coprecipitation of lanthanum and cerium oxide, were evaluated. Materials were analyzed by BET, AAS, DRIFT-MS, TPR, OSC, XRD, and SEM-EDX. Samples were tested in ethanol steam reforming (ESR). Both lanthanum-promoted samples exhibited a higher stability in time than nonpromoted catalyst. Nonetheless, catalytic behavior is strongly affected by the preparation method. TPR, OSC, and XRD analyses showed that the coprecipitation method allowed the best interaction between ceria and lanthana, leading to an increased redox ability and best catalytic performances as a result. A catalyst with a support prepared via the coprecipitation method showed ethanol conversion of 90% and hydrogen selectivity higher than 70% even after 60 h of reaction.