Preparation Of Amorphous Ni-P Alloy And Its Catalytic Activity For Hydrodeoxidation

Along with the development of society and economy,the continuing consumption of petroleum resources emerges as a serious problem,making that to seek new energy sources becomes a urgent issue.Biomass oils are considered as the most potential renewable energy source to replace petrochemical resources.They nonetheless contain a variety of organic compounds which own oxygen atoms,resulting in a lower calorific value than traditional petrochemical energy sources,so that it is necessary to refine biomass oils to meet the fuel standard.Among all kinds of catalysts,noble metal catalysts are widely used for upgrading biomass oils because of their good catalytic activity.However,the wide application of noble metal catalysts is limited by their low storage and high cost.Therefore,it is urgent to develop non-noble metal catalysts with high activity and stability.Amorphous alloy catalysts not only have the advantages of low cost,strong toxicity resistance,less environmental pollution in the preparation process and non-spontaneous combustion in the air,but also have the unique structure of short-range order and long-range disorder,which can produce a large number of chemical equivalence and coordination unsaturated active centers on the surface and show excellent catalytic activity in many hydrogenation reactions.In this paper,a series of amorphous Ni-P,Ni-M-P(M is W,Co,Mo,Cu and Cr)and Ni-Co-P/HAP(hydroxyapatite)alloys were prepared through chemical reduction method,and their structures were characterized by XRD,SEM and XPS analyses.The HDO performance of the catalysts were investigated by using the HDO reaction of vanillin as a probe.The results revealed that the Ni-P amorphous alloy synthesized with NiCl₂·6H₂O as nickel source,KBH₄ as reducing agent and pH=9 had good properties,and the catalyst particle sizes are more uniform.Ni-Co-P amorphous alloy was modified by adding additive Co,and Ni-Co-P amorphous alloy was synthesized.The synergistic effect between Ni and Co not only contributed to the reduction of Ni,but also increased the number of active centers of catalyst,and improved the extent of dispersion and disorder of amorphous alloy.Loading amorphous alloy Ni-Co-P on to the support HAP improved the catalyst through increasing specific surface area,promoting its hydrophilicity,reducing the particle size,and enhancing its thermal stability.When hydrogen gas was used as the hydrogen source,compared to the Ni-P and Ni-Co-P amorphous alloys,Ni-Co-P/HAP exhibited better catalytic activity in the hydrodeoxygenation of vanillin.The conversion of vanillin and the selectivity of MMP were 100%and 92.8% respectively under the reaction condition of which the loading content of Ni was 50%,the pressure of H₂ was 2.0 MPa,the temperature was 150?,the reaction time was 180 min and the amount of catalyst was 0.05g.The conversion of vanillin maintained 100%and the selectivity of MMP was 84.7%after the catalyst was recycled for 5 times.Ni-Co-P/HAP amorphous alloy still had good hydrodeoxygenation effect when used to catalyze other oxygenated compounds.Using formic acid as hydrogen donor,isopropanol as solvent and Ni-Co-P/HAP amorphous alloy as catalyst,the effects of reaction solvent,the amount of formic acid additive,reaction temperature,time and amount of catalyst on vanillin HDO reaction were investigated.The results showed that the conversion of vanillin and the selectivity of MMP decreased with the increase of polarity and acidity of hydrogen donor.The conversion of vanillin reached 97.9%and the selectivity of 2-Methoxy-4-methylphenol(MMP)was 94.0%under the reaction condition of which the m_vanillin:m_{formic acid}=1:2,the temperature was 200?,the reaction time was 300 min,the amount of catalyst was 0.06g.