The Synthesis And Application Of Ni Based Noble Metal Catalysts On Hydrodeoxygenation Of Biomass Model Compounds And Hydrolysis Of Sodium Borohydride

In order to improve the life quality of people and promote social and economic development,renewable energy and clean energy have attracted the current research focus.Biomass and hydrogen has been considered as one of the alternative energy sources of oil.However,due to the high content of water and oxygen,biomass can not be used directly.Biomass model compounds such as phenol,glycerol,levulinic acid and ethyl levulinate can be used to produce various high value-added products by catalytic hydrodeoxygenation(HDO).In addition,hydrogen is also considered as a kind of new energy,and hydrogen production and storage has a great research value.In the first part of this paper,Pd-Ni2P/SiO2 catalyst was prepared by sol-gel and temperature-programmed reduction method.The catalysts were characterized by XRD,ICP,TEM,CO-IR,TG,XPS and elemental analysis.The HDO reaction performances of Pd/SiO2,Ni2P/SiO2 and Pd-Ni2P/SiO2 catalysts in phenol aqueous system have been compared,especially the stability of the catalysts and the change structure of the catalysts before and after the reaction.The results show that the Pd-Ni2P/SiO2 catalyst has a good stability in phenol HDO,which can maintain 89%phenol conversion and 87%cyclohexane seletivity after four times of HDO reaction,while the selectivities of Pd/SiO2 and Ni2P/SiO2 catalyst after four times for HDO reaction were decreased from 96%and 90%to 21%and 30%,respectively.The results of ICP,XPS,TEM and elemental analysis showed that the loss of Pd content on Pd/SiO2 was 36.2%after four times of HDO reaction,and the active components were agglomerated.The average particle size increased from 2.8 nm before the reaction to 7.8 nm after four times of reactions,and a certain degree of carbon deposition occurred.After four times of phenol HDO reaction,due to the presence of water in the reaction system P in Ni2P/SiO2 was oxidized.And after four times of HDO reaction loss of P reached 45.4%with a small amount of agglomeration.In contrast,the activity of Pd-Ni2P/SiO2 in the HDO reaction of phenol aqueous system still had excellent reaction performance after the four reactions,in which the catalyst can still maintain the crystal integrity.The active component is not lost and the reaction can maintain high dispersion.In addition,Ni2P/SiO2 and Pd-Ni2P/SiO2 catalyst were used to carry out HDO reaction with glycerol,levulinic acid and ethyl levulinate,respectively.It was further demonstrated that Pd-Ni2P/SiO2 catalyst still showed better HDO performances in fatty hydroxyl group and carbonyl group.In the second part,a high specific surface carbon aerosol(CA)was prepared by using phenolic resin under hypersaline conditions.The Ni@Ru-RuO2/CA was prepared by using the carbon aerosol as carrier to support the active metal Ni and Ru.The results show that the average particle size of the catalyst is only 2.6 nm and the dispersion is uniform.On the other hand,due to the exist of Ru-RuO2,there are a lot of oxygen vacancy on the surface of the catalyst,which enhance the dissociation of water.Therefore,the Ni@Ru-RuO2/CA catalyst has a good hydrogen-generating activity.In addition,the effects of prepapation conditions of Ni@Ru-RuO2/CA catalyst,such as different HNO3 treatment temperatures and different hydration hydrazine reduction temperatures have been studied.The results showed that the Ni@Ru-RuO2/CA catalyst prepared under 60? HNO3 treatment for 12 h and 60? hydrazine reduction showed better hydrogen production activity.