Synthesis and catalytic activity of sol-gel derived La-Ce-Ni perovskite mixed oxide on steam reforming of toluene

Hybrid metal ion and polyvinyl alcohol (PVA) was prepared to obtain La1-xCexNiO3 (x = 0, 0.2, and 0.4) perovskite-type catalyst powder by sol-gel method. Metal ion to PVA monomer molar ratio was assigned at 1:1. The metal ion formed into complex precursors with alkoxide to improve the elemental dispersion and prevent agglomeration of obtained catalyst which is strongly related to activity and stability on syngas generation. As-prepared catalysts were calcined at 800 degrees C and characterized. X-ray diffraction pattern confirmed high crystalline of LaNiO3 perovskite structure and additional CeO2 phase was founded when La was partial substituted by Ce. The crystal size and particle size of La1-xCexNiO3 tended to decrease with higher Ce content. SEM and EDS results confirmed good elemental dispersion with homogeneous structure and low agglomeration. Particle size and surface area were in the range of 13.85 -16.70 mu m and 2.40-5.87 m(2)/g, respectively. Temperature programmed reduction (TPR) of prepared catalyst show highest H-2 consumption at 390 degrees C and 700 degrees C which were attributed to the partial reduction of Ni3+ to Ni2+ and Ni2+ to Ni-0, respectively. Activity of catalyst on steam reforming of tar was investigated using toluene as model compound in a fixed bed quartz reactor at 500-800 degrees C with steam/carbon molar ratio of 2:1. Carbon and hydrogen conversion were interpreted in term of CO2, CO, H-2, and c(x)H(y) as CH4. The effect of operating temperature appeared to improve favorable fuel gas species formation in terms of selectivity and quantity. Addition of La0.6Ce0.4NiO3 catalyst promoted conversion of toluene to CO and H-2 at the highest yield of 57.26% and 76.62% at 800 degrees C, respectively. Moreover, catalysts showed favorable stability because no deactivation was observed during the 180 min of test. LHV of syngas obtained can be used for power production without need for auxiliary fuel. (C) 2012 Elsevier B.V. All rights reserved.