Preparation And Properties Of Ni-based Catalytic Materials For Water Electrolysis

Hydrogen plays a very important role in the field of new energy,which has the advantages of abundant reserves,recycling,high efficiency and so on.Among them,the method of hydrogen production by electrolysis of water has the advantages of simple operation and no pollution,and it is an efficient way to regenerate energy,however,at present,there exists the problem of high overpotential and high energy consumption in hydrogen from electrolytic water,which makes the preparation of catalyst for hydrogen production by water decomposition become the critical.In this paper,three-dimensional porous structure nickel foam was selected as the experimental substrate,and ion-doping of foam nickel was carried out by electrodeposition cyclic voltammetry,and Fe-Co-Ni-Mo catalyst and Fe-Co-Ni-Mn catalyst were successfully prepared.The advantages and disadvantages of hydrogen evolution performance were analyzed.1.The hydrogen evolution effect of Fe-Co-Ni-Mo catalyst was estimated through linear sweep voltammetry(LSV),and 1.0 M KOH solution was selected as the alkaline electrolyte.The overvoltage was simply 264.8 m V when the current density was 10m A/cm~2,indicating that the fabricated catalyst has excellent properties.Based on this,the stability of the catalyst was also measured.When the current density was 100 m A/cm~2,the hydrogen overvoltage fluctuated around 426.6 m V.In the experimental test process for 10hours,the potential fluctuation was merely 15 m V.The experimental results reveal that the catalyst has excellent stability.Through the electrochemical impedance test,the charge transfer resistance of the electrode was 67.18Ω.The charge transfer resistance of Fe–Co–Ni–Mo catalyst is small in the process of reaction,which significantly improves the activity of the catalyst in the catalytic process.Through the calculation of its electrochemical active area,it is displayed that the electrochemical active area of Fe–Co–Ni–Mo electrode was 142.5 cm~2,which was much larger than that of blank nickel foam,which provides more reactive sites for hydrogen evolution reaction.2.In addition,Mn ions doped on Fe–Co–Ni electrode can also play a catalytic role.The overvoltage was about 367.8 m V with the current density was 10 m A/cm~2.It has better catalytic performance for hydrogen evolution than Ni electrode and Fe-Co-Ni electrode.In the stability test,when the current density is 100 m A/cm~2,the overpotential of hydrogen evolution reaction fluctuates around 516.4 m V,and in the period of 10-hour test,the fluctuation of potential is only 11 m V,indicating that the electrode has excellent stability.The charge transfer resistance of the electrode was obtained by the electrochemical impendance measurement,which was 91.87Ω.The addition of Mn ions promotes the conductivity of Fe–Co–Ni catalyst.The electrochemical active area of Fe–Co–Ni–Mn electrode was 88 cm~2 and that of blank nickel foam was 17.5 cm~2.It can be seen that the addition of Mn ion increases the surface area of electrochemical activity of Fe–Co–Ni catalyst and improves the catalytic activity of Fe–Co–Ni catalyst.