Ni-Fe catalyst derived from mixed oxides Fe/Mg-bearing metallurgical waste for hydrogen production by steam reforming of biodiesel by-product: Investigation of catalyst synthesis parameters and temperature dependency of the reaction network

摘要

This study focuses on a thorough investigation of the effect of synthesis parameters (nickel content and preparation method) and operating temperature on the physiochemical properties and catalytic performance of Ni promoted Fe/Mg-bearing metallurgical waste catalyst (Ni-UGSO) for hydrogen production by glycerol steam reforming. The best results were achieved by incorporating 5 wt.% Ni by solid-state impregnation method (SSI-5%Ni-UGSO), leading to almost complete glycerol conversion to gaseous products. Higher H-2 yield (80.7 %) and very low coke formation (0.59 mg(coke) h(-1) (m(2)/g(cat))(-1)) are the advantages of working at 580 degrees C by favouring the water-gas-shift (WGS) reaction, whereas increasing temperature to 730 degrees C allows to almost suppress coke formation (0.18 mg(coke) h(-1) (m(2)/g(cat))(-1)) mainly by limiting the Boudouard reaction, with the drawback of a lower hydrogen yield (59.4 %). This notable catalytic behavior was ascribed to the synergic cooperation between Ni and Fe/Mg containing species inside UGSO, through the formation of Ni-FexOy and Ni-MgO active sites.