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

摘要

Abstract 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, H₂-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.