Study On Hydrogen Production Performance Of Sodium Borohydride/Nano Aluminum Powder Hydrolysis

While the development of science and technology improves people’s living standards,it is also accompanied by problems such as the gradual depletion of fossil energy and environmental pollution.Among many new energy technologies,hydrogen energy stands out due to its advantages of environmental protection and high energy density.In the application of hydrogen energy,the preparation of hydrogen has become a key link.Among them,sodium borohydride has been widely studied due to its theoretical high hydrogen productivity,safety and environmental protection,while aluminum has been widely studied because of its low price and abundant reserves.Therefore,it is of great significance to study the hydrolysis of sodium borohydride/aluminum to produce hydrogen.This paper mainly studies the effect of NaOH,H₂O,CoCl₂ and graphene on the performance of NaBH₄/Al system for hydrogen production.Mainly in the NaBH₄/Al system with different ratios,the hydrogen production performance of the entire system was explored by changing the ratio and content of NaOH,H₂O,CoCl₂,and the optimal ratio was determined according to the hydrogen release rate and the hydrogen release amount.Then,based on the optimal ratio,the effect of graphene in different dispersion modes on the hydrogen production performance of NaBH₄/Al system was studied.In addition,the experiment also carried out SEM and EDS analysis of NaBH₄/Al hydrolysate.The results show that changes in the ratio and content of NaBH₄/Al,NaOH,H₂O,CoCl₂will have an effect on the hydrogen production performance of the entire system.When the ratio of NaBH₄/Al is constant,the increase of NaOH content will accelerate the hydrogen release rate and the hydrogen release amount by NaBH₄/Al.The increase of H₂O content will reduce the hydrogen release rate and the hydrogen release amount by the system.The rate of hydrogen release will accelerate with the increase of CoCl₂ content.Comprehensive experimental data shows that the best ratio is when NaBH₄:Al=1:1,NaOH:NaBH₄/Al=1:1,H₂O is 15mL,CoCl₂ is 14%,and the amount of hydrogen released is 3010 mL·g^-1,the hydrogen evolution rate is 68.41 mL·min^-1·g^-1.The study of graphene found that the addition of graphene has a significant effect on the hydrogen production performance of the NaBH₄/Al system.Under the optimal ratio,when the addition amount of graphene-2 is 0.01g,the hydrogen release performance of the entire system will be the best.The amount was 3300 mL·g^-1 and the hydrogen evolution rate was 82.5 mL·min^-1·g^-1.According to SEM analysis of NaOH,H₂O,CoCl₂ and graphene affecting the hydrolysate of NaBH₄/Al system,as the proportion of NaOH increases,the microscopic morphology of the hydrolysate changes from small particles to large particles.The increase of H₂O content will gradually change the microscopic morphology of the hydrolysate from large particles to small particles and cause agglomeration.Hydrolysis products of NaBH₄/Al catalyzed by different ratios of CoCl₂ have irregular granular structure.The amount of graphene added has no obvious effect on the microstructure of the hydrolysate,but compared with the hydrolysate without addition of graphene,it can be seen that the addition of graphene-2 will change the microstructure of the hydrolysate,transforming it from irregular granular to regular granular structure,thereby improving the hydrolysis of NaBH₄/Al Hydrogen production performance.The EDS analysis shows that as the NaOH content decreases,the O and Na element content decreases and the Al element content increases.When the NaOH content is 0g,NaBH₄hydrolysis is inhibited,As the content of H₂O increases,the content of O and Al elements increases,indicating that the precipitation of Al（OH）₃ in the hydrolysate is increasing.Under the optimal hydrolysis conditions,the main elements in the hydrolysate are O,Al,Co,B,Na,and the hydrolysates are NaBO₂ and Al（OH）₃.