Hydrogen Generation By Aluminum-water Reaction In Acid And Alkali Medium

The combustion of fossil fuels causes the serious air pollution.Therefore,the investigation of the renewable and clean fuel is important.Hydrogen with high energy density,no pollution and rich in nature becomes attractive.There are several methods to produce hydrogen,including the metal-water reaction,the electrolysis of water etc.Among these methods,Al-H₂O reaction has been investigated.However,the dense aluminum oxide film on the surface hinders this reaction.Presently,several methods have been developed,such as active aluminum by ball milling,changing the reaction media,preparing the alloy etc.In this work,Al-H₂O reaction in acidic and alkali media was examined.Meanwhile,the microstructure of the product was characterized by XRD and SEM-EDX and the reaction mechanism was analyzed by kinetic calculation and electrochemical test.The main conclusions are following:?1?Hydrogen generation by Al-H₂O reaction in different acid and alkali medium was studied.The results indicate that the reaction rate and the H₂ volume in acidic or alkaline media increase with increasing temperature and the mass.Co agglomerates with increasing temperature and the concentration,which hinders the hydrogen generation.?2?The kinetics of hydrogen production from aluminum-water reactions in different acidic and base media was studied.The results indicate that the aluminum-water reaction kinetics model and the reaction mechanism in different media varies.In different media,the pH of the solution,the solution state and the presence of ions and solid particles in the solution have a greater impact on the aluminum-water reaction.?3?The effect of Co on aluminum-water reaction was studied.It is found that the addition of Co promotes Al-H₂O reaction in different media.The morphology and size of Co is changed after Al-H₂O reaction.Increasing Co,the induction period is decreased and the reaction rate is increased.Meanwhile,the amount of hydrogen increases.The potential decreases after adding Co,which is beneficial to Al-H₂O reaction.