Preparation And Performance Of Stainless Steel-based Alkaline Electrolyzed Water Catalysts By Electrodeposition

The issue of environment and energy had always been a hot topic.Environment pollution and energy drying up were the difficult problems in 21st centry.It is particularly important to develop a new renewable and clean energy sources.Hydrogen energy has received much attention due to its high energy density,and combustion pollution-free.Electrolytic water was the main method of hydrogen production,but the key to large-scale hydrogen production by electrolytic water was to develop low-cost and abundant electrocatalysts instead of precious metal-based ones.For the development of non-precious metal electrocatalysts,the main work and conclusions were as follows:1.304 stainless steel mesh（SS）was selected as the matrix;Co-Ni double hydroxides was prepared by electrodeposition and spinel Co-Ni oxides were produced by vacuum calcination.The crystal structure,morphology and electrocatalytic OER performance of electrocatalysts were studied by XRD,SEM,TEM,XPS and electrochemical workstation The Co₂Ni₁O₄/SS electrocatalysts exhibits an outstanding OER catalytic activity with an overpotentials of 240 mV at 10 m A cm^-2and a Tafel slop as low as 53.92 mV dec^-1in 1.0M KOH.Continuous 72 h cycle stability tests showed that the electrocatalyst has good stability.2.It is found that nickel ion has a strong oxygen evolution ability,and molybdenum has strong hydrogen adsorption ability.If molybdenum and nickel are fused together,water electrolysis can be effectively promoted.SS was selected as the self-supporting material,and the two elements were combined by one-step electrodeposition method.The electrocatalyst containing Mo Ni₄alloy（NiMo/SS）was successfully prepared on the surface of SS.It showed excellent catalytic performance for HER and OER in 1.0 M KOH.When the current density is 10 m A cm^-2,the HER overpotential is 53 mV and the OER is261 mV.Cyclic stability tests of HER and OER for 96h and 72h were carried out continuously.The results showed that the electrocatalysts have excellent HER stability and good OER stability.The appearance of the tiny particles formed by the electric deposit was helpful to increase the specific area,expose more active spots,and promote the electric reaction..3.The above experimental results are insufficient in terms of OER,so we conducted the second electrodeposition on NiMo/SS to prepare NiCe@NiMo/SS electrocatalysts.SEM,TEM,XRD and XPS tests showed that CeO₂was successfully coated on the surface of NiMo/SS catalyst.In 1 M KOH solution,the overpotential of OER is 273 mV at 10 m A cm^-2,which is close to that of NiMo/SS（261 mV）.The overpotential（376 mV）at 200 m A cm^-2is equal to NiMo/SS,but the electrocatalyst can achieve higher current density(500m A cm^-2).A 40-hour stability test showed only a 5%attenuation at 100 m A cm^-2.Through the method of two times of electric deposit,the CeO₂and MoO₃heterostructure were successfully made on the surface of the SS.The introduction of Ce increases the electron transfer rate.promote the OER process.