A novel synthesis of NiAl2O4 spinel from a Ni-Al mixed-metal alkoxide as a highly efficient catalyst for hydrogen production by glycerol steam reforming

A novel method was developed for the synthesis of a more easily reducible NiAl2O4 spinel, which was tested as catalyst for hydrogen production by glycerol steam reforming. A Ni-Al mixed-metal alkoxide was firstly prepared through solvothermal method and then calcined using a two-step calcination technique. XRD, N-2 physisorption, H-2-TPR, XPS, SEM, and TEM results show that this new catalyst is more readily reducible and possesses a more developed porous structure with higher surface area. It therefore exhibits high H-2 yield (76.38 %) and glycerol conversion into gaseous products (95.42 %). To avoid or reduce coke formation, 10 wt.% CeO2 was incorporated into the catalyst structure. TGA, TEM, and Raman spectroscopy analyses reveal the suppression of coke by a large extent due to the formation of well-dispersed CeAlO3, which decreases significantly the filamentous carbon formation rate on nickel surface and promotes coke gasification by providing oxidative environment around nickel active sites.