Mesoporous Ni/MgO Catalyzes The Conversion Of Biomass Oil To Hydrogen Production And Reactivity Analysis

In order to study the activity of mesoporous Ni/MgO in hydrogen producti on by the steam reforming of commercial biomass oil and the reaction mechanis m of biomass oil to hydrogen,the mesoporous Ni/MgO catalyst was prepared an d was characterized using N2 adsorption/desorption,XRD,and H2-TPR.The stea m reforming of furfural,simulated biomass oil and commercial biomass oil for h ydrogen production was performed over the Ni/MgO catalyst using a fixed-bed r eactor.The surface reaction of furfural and simulated biomass oil on the mesopo rous Ni/MgO catalyst was tested using the methods of Programmed-Temperature-Desorption（TPD）and Programmed-Temperature-Surface-Reaction（TPSR）.The results of N₂ adsorption/desorption show that the average pore sizes of the prepared MgO support and NiO/MgO precursor are 14.62 and 15.29 nm,respectively,and the BET specific surface areas reach 58.60 and 55.74 m²/g,respectively.XRD results also prove that the prepared catalyst exhibits the properties of mesoporous structure.The H2-TPR results show that the reducibility of Nickel is 16.7%in NiO/MgO precursors with a Nickel loadings of 16.0 wt.%.The results of steam reforming of furfural showed that the furfural conversion,H₂yield and H2 selectivity increased with enhancing the reaction temperature at the ratio of water-to-carbon S/C=20 mol/mol.At 600 ^oC,the conversion of furfural reached 94.9%,H₂ yield and H₂ selectivity were 83.2%and 68.6%,respectively.The steam reforming of two-component simulated biomass oil showed that the addition of acetic acid or hydroxyacetone increased the hydrogen yield compared to steam reforming of furfural.The steam reforming of commercial biomass oils indicated that the commercial biomass oils need to be diluted with water to avoid the catalyst carbon deposits blocking the reactor before used as reactants.At 600 ^oC,the yield and selectivity of H₂ increased with enhancing the ratio of water-to-carbon.At S/C=20 mol/mol,the conversion of furfural,acetic acid,and hydroxyacetone,the main organic components of the biomass oil,was all over 90%.At the same time,the yield and selectivity of H₂ reached 81.0%and 72.0%,respectively,which were lower than the H₂ yield from the steam reforming of furfural.This result may be from the affection of inert reactants in the biomass oil on the steam reforming of active reactants.The results of TPD and TPSR of the simulated biomass oil over the Ni-based catalyst showed that the intermediate products formaldehyde HCHO and acetone CH3COCH3 was included in the conversion of biomass oil to H2.Meanwhile,the by-products of COx and CH4 were also produced in the conversion of biomass oil to H2.