Catalytic Steam Reforming of Propane over Ni/LaAlO3 Catalysts: Influence of Preparation Methods and OSC on Activity and Stability

To develop an efficient catalyst for steam reforming of propane, Ni/LaAlO3 catalysts were prepared by deposition precipitation, impregnation, and solvo-thermal methods, and characterized by XRD, BET, H-2-TPR, elemental analyses, and TEM. Ni/Al2O3 and Ni/CeO2 catalysts were also synthesized by the solvo-thermal method for comparison. The Ni/LaAlO3 catalysts exhibited better catalytic performance than both Ni/Al2O3 and Ni/CeO2 catalysts, and activities with Ni/LaAlO3 were found to be dependent upon the preparation methods. In particular, the Ni/LaAlO3 catalyst synthesized by the solvo-thermal method exhibited the highest activity presumably because tetrahydrofuran helps distribute generated Ni nanoparticles onto the catalyst surface in a uniform fashion. In addition, the solvo-thermally prepared Ni/LaAlO3 catalyst was found to be highly stable, with its activity being maintained at least during 100 h. The observed high stability is attributed to the excellent oxygen storage capacity of LaAlO3, which was first determined by thermogravimetric methods as well as by soot oxidations in the presence of Al2O3, CeO2, and LaAlO3. Compared to the Ni/Al2O3 and Ni/CeO2 catalysts, Ni/LaAlO3 exhibited suppressed carbon formation even at lower S/C ratios due to the superior oxygen transport ability of the LaAlO3 support.