Application Of Electrocatalyst Derived From Derived Zeolite Imidazole Material In Electrolysis Water

Hydrogen energy,which is pollution-free,renewable and has a high energy storage density,is considered to be likely to replace oil and coal and other fossil fuels that are running out.Water splitting water is the most pollution-free way to produce hydrogen.In the near future,electrolysis of water will become one of the key technologies for hydrogen production.However,electrolysis involves OER and HER,both of which require high overpotentials.At present,Pt,Ir and other noble metal based catalysts have high catalytic activity for hydrolysis.However,the low abundance and high cost of precious metals limit the large-scale application of electrolysis of water for hydrogen production.This paper focuses on the reduction of noble metal load and the improvement of catalytic performance,by introducing ZIFs,a material with a high surface area and a fixed pore structure as a carrier,then loading Ir,Pt or other precious metals with catalytic activity on ZIFs,and finally carbonizing at high temperature under the atmosphere of reducing gas,a nitrogen-doped carbon nanocomposite with noble metal particle structure is formed.The material of this structure can not only greatly reduce the amount of precious metal in the catalyst,but also further improve the catalytic performance of electrolyzed water by electron transfer between metal and carbon.In this paper,CoZn bimetallic ZIFs are used as precursors.IrCo NPs-900and Pt-WC-0.1 NPs were used as electrolyzed water catalysts.The morphology and elemental composition of the materials were analyzed by physical characterization methods such as XRD,SEM,TEM,EDS and XPS.The catalytic properties of the materials were evaluated by electrochemical test.The main contents of the thesis are as follows:?1?CoZn bimetallic ZIFs were used as precursor,H₂Cl₆Ir was doped into the precursor using pores of ZIFs,Then,a high-temperature carbonization in a reducing gas atmosphere was carried out to prepare IrCo NPs-900 catalyst with nitrogen-doped carbon and carbon nanotube-coated IrCo alloy.Studies show that the prepared IrCo NPs-900 catalyst has a large electrochemical surface area and a fast charge transfer rate,and shows good stability to HER and OER.Electrochemical tests show that IrCo NPs-900 has excellent catalytic activity against HER,OER and total hydrolysis in acidic solution.Specifically,in 0.5 M H2SO4 solution,for HER,achieving a current density of 10 mA cm^-2 requires only an Overpotential of 23.9 mV,which is even slightly better than the catalytic performance of commercial Pt/C?24.7 mV?.For OER,achieving a current density of 10 mA cm^-2 requires only an overpotential of 270mV,which is lower than 320 mV of IrO₂.In addition,IrCo NPs-900 reach 10 mA cm^-2 during overall water splitting at a cell voltage of only 1.55 V.?2?Still using CoZn bimetallic ZIF as precursor,Pt-WC-0.1 NPs catalyst with high catalytic activity for HER was prepared by incorporating H2Cl6Pt and?NH₄?₆H₂W₁₂O₄₀.The results show that there is a synergistic effect between Pt and WC in Pt-WC-0.1 NPs,and the presence of WC can enhance the electrocatalytic activity of Pt.Pt-WC-0.1 NPs requires only an Overpotential of 23 mV to achieve a current density of 10 mA cm^-22 for HER in 0.5 M H₂SO₄,which is lower than 33 mV of commercial Pt/C.Pt-WC-0.1 NPs requires an Overpotential of 42 mV to achieve a current density of 10 mA cm^-2 in 1M KOH,which also ia slightly lower than 44 mV of commercial Pt/C.In addition,Pt-WC-0.1 NPs exhibited good electrochemical stability to HER in both acidic and alkaline electrolytes.