Effect Of Magnetic Field On The Aluminum Electro-Deposition In The Ionic Liquid

Aluminum electro-deposition in ionic liquids itself is advanced to the traditional aluminum production,such as the operation temperature cutting several hundred degree Celsius to room temperature,and avoiding to the corrosion of equipment and environmental pollution.However,the technology has still some problems which aluminum layer are thin,porous and falling down easily.Marcus's "electron transfer theory" showed that magnetic field could accelerated the electron transfer.In this project,the effect of magnetic field on the aluminum electro-deposition was investigated in the chlorination of 1-ethyl-3-methyl imidazole ionic liquid.Cyclic voltammetry,chronoamperometry,AC impedance,constant current density methods were used to obtain the relationships of magnetic field with the electrode interface double layer behavior and aluminum nucleation formation.The technical parameters of magnetic field,current density and time were investigated.And through orthogonal experiments,the appropriate conditions of aluminum electro-deposition were obtained.The results indicated that the magnetic field increased the capacitance of double layer between the electrode interface and ionic liquid,and it's thickness was reduced.The aluminum reduction on the electrode was a quasi-reversible process,and magnetic field accelerated electron transfer from the electrode interface to aluminum cation.Magnetic field improved the mass transfer too,but it was not linear relationship.The deposition of aluminum on the glassy carbon electrode surface was confirmed to be three-dimensional transient nucleation mechanism controlled by electrochemical polarization.Magnetic field pushed up the aluminum nucleation formation,and the crystal nucleus became the smaller.The sequence of factors affecting to the aluminum electro-deposition were the magnetic field,current density and time.The appropriation electro-deposition parameters was 36.9mT,0.0035A for 3h in the[EMIM]Cl and AlCl3 molar ratio was 1:2,the obtained aluminum layer thickness was about 78?m and dense.