ESCALONA, N.; ARANZAEZ, W.; LEIVA, K.; MARTÍNEZ, N; PECCHI, G.:
Applied Catalysis A: General 481 (2014) 1-10.
The effect of the substitution of cerium on the catalytic conversion of guaiacol over Ni-based catalysts prepared from the reduction of La1-xCexNiO3 perovskite-type oxides (0.0 <= x <= 0.9) has been investigated. The thermal behavior under reductive atmosphere indicates a beneficial effect of Ce addition. The characterization of the calcined La1-xCexNiO3 perovskites and reduced Ni-based catalysts by atomic absorption spectroscopy (AAS), adsorption of N-2 (-196 degrees C), transmission electron microscopy (TEM), X-ray powder diffraction and temperature programmed reduction (TPR) revealed significant differences in crystalline structure and reducibility. The Ni-reduced materials were effective in catalyzing the conversion of guaiacol to cyclohexanol. The catalysts with Ce content x <= 0.3 displayed similar initial intrinsic rate. The highest activity was obtained for the catalysts with Ce content x = 0.5 and 0.7 which was ascribed to the highest thermal stability under reductive atmosphere of CeO2-solid solution partially substituted with La. The Ni-reduced catalysts displayed a high selectivity to cyclohexanol and methoxycyclohexanol compounds and the catalysts with X-Ce = 0.5 presented a high stability in the guaiacol conversion.