CO2 reforming of methane over La2NiO4/α-Al2O3 prepared by microwave assisted self-combustion method

La2NiO4/alpha-Al2O3 catalyst was prepared by a microwaves assisted self-combustion method using glycine or urea as fuel and metal nitrates as oxidizers. In order to understand the effect of the preparation method and the fuel type used on the catalytic properties, a sample was prepared by an incipient wetness nitrate impregnation method (without fuel). All obtained samples were used as catalysts precursors for the CO2 reforming of methane to syngas between 500 and 800 degrees C. The catalysts were characterized by X-ray diffraction (XRD), specific surface area measurements (BET), temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), before and after reactivity tests. XRD analyses indicate the formation of La3Ni2O6.92, La2NiO4 and LaAlxNix-1O3 crystalline structures independently of the preparation method. All samples prepared with fuel showed high CH4 and CO2 conversions with low carbon deposition. No change was observed in the crystalline structure of the perovskite-related oxides. On the other hand, the sample prepared by nitrate impregnation showed high activity but destruction of the perovskite-related structure with significant carbon formation, mainly multi-walled carbon nanotubes. (C) 2010 Elsevier B.V. All rights reserved.