Preparation Process Of Cerium Cobalt Oxide Based On Prussian Blue Analogue And Its Electrocatalytic Oxygen Evolution Performance

The rapid development of human society requires the consumption of large amounts of non-renewable fossil energy.As energy depletion and environmental pollution problems become more and more serious,it is urgent to find a clean and renewable energy to replace traditional fossil energy.An important way to solve this problem.Water decomposition is divided into two half reactions,the hydrogen evolution reaction（HER）and the oxygen evolution reaction（OER）.Since the oxygen evolution reaction involves multiple proton-coupled electron transfer processes,the oxygen evolution kinetics is slow,which limits the efficiency of electrocatalytic water decomposition.Although precious metal catalysts commonly used in industry such as Ru,Ru O₂,Ir,and Ir O₂show excellent catalytic performance,their reserves are scarce and expensive,restricting their large-scale applications.Therefore,it is an urgent problem to find an electrocatalyst with good catalytic activity,high reserves and low cost.Prussian blue analogous（PBAs）with a metal organic framework（MOF）structure has gradually become a template for the development of high-performance catalysts in recent years due to its abundant raw material reserves,simple synthesis process,and unique structure.The purpose of this paper is to use the porous properties of cerium-cobalt Prussian blue analog precursors to synthesize composite oxides by high-temperature oxidation to obtain OER electrocatalytic materials with high catalytic activity and good stability.The details are as follows:（1）Co-precipitation method was used to prepare cerium-cobalt Prussian blue nanoparticles by adjusting the synthesis parameters.The influence of reaction parameters on the morphology and particle size of the synthesis products was revealed through the control variable method.The effect of catalytic performance.Among them,the particle size of the product decreases first and then increases as the concentration of the reactant decreases;the morphology of the product gradually becomes complete with the temperature increasing;the particle size gradually increases as the reaction time increases,and the morphology gradually It tends to be regular;the particle size decreases first and then increases as the concentration of surfactant increases,and the morphology gradually becomes regular;the type of surfactant has a great influence on the morphology and particle size.The addition of sodium dodecyl benzene sulfonate（SDBS）makes the product obtain the smallest particle size and relatively most regular morphology.（2）Using cerium-cobalt Prussian blue particles as a precursor,cerium-cobalt composite oxides were prepared by high-temperature calcination in air,and the effects of reaction temperature and reaction time on the morphology of the composite oxides were systematically studied.The results show that as the temperature increases,the pores on the surface of the product gradually increase,with the most pores at 650℃and the best catalytic performance.With the increase of time,the pores of the cerium-cobalt composite oxide particles gradually disappeared due to recrystallization,and the pores disappeared until the temperature was kept for 3 hours.The cerium-cobalt composite oxide showed the best catalytic activity when kept for 0.5 hours.（3）The synthetic cerium-cobalt oxide was made into a glassy carbon electrode,and the three-electrode electrochemical test showed that the catalyst only needed an overpotential of365 mv to drive a current of 10 m A cm^-2,and the corresponding Tafel slope was only 105 m V dec^-1.The rate-determining step（RDS）was calculated using the Tafel slope,and the results showed that RDS involved one electron transfer step.The charge transfer resistance R_ctis 5.23Ωand the effective active area C_dlis 14.22 m F cm^-2,both of which are better than the catalytic performance of Ce O₂and Co₃O₄.This shows that the preparation of cerium-cobalt oxide based on Prussian blue structure can further improve the activity of the electrocatalyst,and has important reference significance for the development of low-cost and high-efficiency hydrolytic catalysts.