Study On Preparation Of Transition Metal Phosphide And Catalytic Hydrogen Production From Sodium Borohydride

With the worsening of global energy and environmental problems, hydrogen is a new kind of energy and has been drawn widespread attention by people.Compared with other various hydrogen production technologies, NaBH4 hydrolysis hydrogen production technology, as convenient, practical and efficient preparation of high-purityH2, has become a excellent hydrogen source for the proton exchange membrane fuel cell.Currently, noble metal catalysts has been researched widely for NaBH4 hydrolysis hydrogen production. However,the noble metal catalyst is scarce and so expensive,which limits its widely practical use.Therefore,this thesis mainly focus on non-noble metal transition metal phosphide catalysts includingtransition metal single-metal phosphide catalysts(Ni2P,Ni12P5,Co2P) and bimetallic phosphide catalysts(NiCoP)for NaBH4 hydrolysis hydrogen production.In this thesis, using Ni2 P,Ni12P5,Co2 P and NiCoPas catalyst,we researched NaBH4 hydrolysishydrogen production.We studiedthe influence of different preparation methods and preparation conditions on the activity of catalysts.The phase,surface structure and chemical composition of catalysts were systematically characterized by XRD、SEM and EDX. In addition,the characterization results of catalysts are associated with their catalytic performance of NaBH4 hydrolysis hydrogen productionrespectively, thus, we can get the best catalyst for hydrogen production.Compared with neutral or acidic conditions, the results show thatNi2 P particles whichwas prepared by hydrothermal method is finer and higher catalytic activity in alkaline conditions, this performancemay be associated with the morphology and size of catalyst. The catalytic activity of Ni2 P particles which was prepared by thermal decomposition of sodium phosphite method is finer and higher than the hydrothermal method,which might be connected with the morphology and size of catalyst. Co2 P and Ni2 P are prepared by thermal decomposition of sodium phosphite method,but,the catalytic activity of Ni2 P is better than Co2 P, which might be concerned with catalyst properties. The catalytic activity of NiCoP are better than Ni2 P,which might be involved with the synergistic effect between metals and electron transfer effect.Furthermore,the kinetics of NaBH4 hydrolysis reaction had also been preliminarily researched in this thesis.We had also been investigatedthe factors of NaBH4 hydrolysishydrogen productionrespectively by the concentrations of NaBH4 and NaOH, the amount of catalyst and reaction temperature.Under mild condition and relatively low concentration of NaBH4, the results showed that the reaction is the first order and the performance of the system is Optimal when the concertrations of NaBH4 and NaOH are 0.1M and 0.3M separately.