Toluene Steam Reforming Using Nickel Based Catalysts Made from Mining Residues

Abstract Two nickel-based catalysts are used for toluene steam reforming: Ni-Olivine and Ni-UGSO (Nickel-UpGraded Slug Oxides). Both catalysts are made from mining residues and prepared by incipient wetness impregnation (IWI). The activity and stability of the two catalysts in toluene steam reforming are investigated and compared, at atmospheric pressure and 800 °C in a fixed bed reactor. Reaction temperature and Ni Loading effects are evaluated for the Ni-UGSO catalyst. The physicochemical properties of the catalysts were analyzed using the following characterization techniques: X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX), X-ray absorption near edge spectroscopy (XANES), Temperature Programmed Reduction (TPR) and Brunauer-Emmett-Teller (BET) specific surface area. Results showed that toluene conversion, mainly into CO and H2, reached up to (98 w%). The catalyst activity was tested in multiple 24 h time-on-stream continuous isothermal runs and no signs of deactivation were observed. Ni in Ni-UGSO has a strong metal-support interaction, which, according to characterization results, is due to the formation of a NiO/MgO solid solution. This catalyst exhibited an elevated catalytic activity along with a high resistance to carbon formation. Ni in Ni-Olivine has shown a weak metal-support interaction leading to the formation of filamentous carbon at the catalyst’s surface.