Preparation,Properties And Applications For Catalyst Of Ammonia Borane From Hydroylsis

In recent years,hydrogen has been considered as the first fossil energy substitute among the new energy sources,due to its green,efficient,safe,abundant and sustainable storage features.Ammonia borane has been widely accepted as the candidate for hydrogen storage material due to its light weight,high hydrogen content,non-toxic,stable at room temperature and 19.6 wt.%mass hydrogen storage density.Ammonia borane can release hydrogen by hydrolysis.The reaction takes place with the participation of catalyst.Transition metal catalysts are widely used to catalyze hydrolysis of ammonia borane due to its low cost and environment-friendliness,and it shows good catalytic performance.However,the disadvantage of agglomeration of metal particles affects the catalytic performance.Therefore,surfactant and carrier are added to prevent the agglomeration of nano-metal particles in order to increase the active site of the catalyst,as well as improve its performance for catalyzing hydrolysis of ammonia borane.In this paper,the performance of catalyst is studied from the preparation method,composition,surfactant and carrier.The main contents are as follows:1.Dendritic Ni_0.19Cu_0.81.81 and Co_0.52Cu_0.48.48 alloy catalysts were prepared by in situ reduction method using starch as surfactant.Composition and morphology analysis results show that the starch as a surfactant can be prepared the dendritic alloy material.The prepared dendritic Ni_0.19Cu_0.81.81 and Co_0.52Cu_0.48.48 alloy have uniform particle size and good dispersity.The performance of the dendritic catalyst was better than the bulk catalystl prepared without surfactant.And Co_0.52Cu_0.48.48 alloy catalyst showed the best catalytic activity,the hydrogen evolution rate was 2179 mL min^-1·g^-1and the activation energy was 37.3 kJ.mol^-1.2.Cd_1-xCu_x?x=0.33,0.5,0.67,0.75,0.8 and 0.83?and Zn_1-xCu_x?x=0.33,0.67,0.75,0.8 and 0.83?nanocatalysts were prepared by in situ reduction method using starch as surfactant.The best hydrogen-release ratio of hydrolysis from ammonia borane was found.The catalytic performance of bimetallic nanocatalyst was better than that of pure Cu,Cd or Zn nanocatalyst.The catalyst with starch as surfactant was better than that without surfactant,and Cd_0.33Cu_0.67.67 nanocatalyst shows the highest hydrogen release rate.3.Boron nitride supported Ni_xCo_1-x?x=0.2,0.25,0.33,0.5,0.67,0.75?metal catalyst were synthesized.The impregnation method make metals supporte on the boron nitride,preventing the agglomeration of the metal particles.This provides more active sites to better contact the catalyst with ammonia borane and water molecules,thereby improving the catalytic activity.The metal catalyst with BN is superior to the Ni_xCo_1-x nano-catalyst.When the content of Ni is 33%,the catalyst has the best catalytic performance.