Steam reforming of n-decane toward H2 production over Ni/Ce-Al2O3 composite catalysts: Effects of M (M = Fe, Co, Cu, Zn) promoters

Abstract

This study involved a kind of nickel supported on Ce-Al2O3 catalyst, and modified it by M (M=Fe, Co, Cu, Zn) promoters, in order to obtain a suitable catalyst that can be used in the process of producing hydrogen by steam reforming of n-decane. Physicochemical characteristics of the catalysts were detected by using automatic adsorption instrument, X-ray diffraction and X-ray photoelectron spectroscopy, temperature programmed reduction, raman spectroscopy, and scanning/transmission electron microscope-energy dispersive spectrometer. It was found that the catalytic activities over series Ni/Ce-Al2O3 and modified Ni/Ce-Al2O3 catalysts were obviously improved compared with Ce-Al2O3 catalyst. Meanwhile, the catalytic activitiy of Ni/Ce-Al2O3 at relatively lower temperature (550°C–650°C) were significantly heightened with the addition of M promoters. Besides, the promotion effect became more stable when the introduction of Fe, which indicated that Fe played an essential role in the catalytic action. The used Fe-Ni/Ce-Al2O3 catalyst was regenerated, and the reforming activity of the reused catalyst was quite close to the results of fresh ones. The valuable information indicated in this work is that based on the specific properties of M-Ni/Ce-Al2O3, three kinds of metal particles can be introduced into Al2O3 by the different way, which should be an effective approach to maintain both catalytic activities, thermal stability and anti-carbon ability.