Highly active and stable Ni/perovskite catalysts in steam methane reforming for hydrogen production

Abstract

Perovskites are good candidates as a catalyst support to enhance the catalytic performance of Ni catalysts in steam methane reforming for hydrogen production. To obtain a Ni/perovskite catalyst with a high activity and stability, different LaBO₃ (B = Al, Fe, Mn), La_0.7A_0.3AlO_3−δ (A = Ca, Ba, Ce, Zn, Sr, Mg) and La_1−xMg_xAlO_3−δ perovskites were prepared and their role in supporting Ni catalysts was comprehensively investigated in the current work. Catalyst characterization methods, including XRD, H₂-TPR, H₂-TPD, XPS, TG and Raman spectroscopy, were also used to understand the underlying mechanisms. The results show that the doping of Ca, Ba, Ce and Zn in the A site of the perovskite lowers the catalytic activity, while the partial substitution of Mg and Sr could improve the activity of Ni/LaAlO₃. More importantly, it is suggested that the Ni/La_0.7Mg_0.3AlO_3−δ catalyst has an outstanding catalytic activity and resistance to carbon deposition, and there is some carbon deposited after a stability test lasting for 35 h. The excellent catalytic performance is determined to be due to the higher dispersion of active Ni, the greater the amount of surface oxygen, the stronger the interaction between the active metal and support due to the partial doping of Mg.