Synthesis, Characterization And Electrocatalytic Oxygen Reduction Of Copper-decorated Polyoxotungstates/Polyoxovanadates

This thesis focus on searching for novel oxygen reduction catalysts with low cost,good stability and high catalytic activities.It was starting from the screening of organic ligands for the preparation of polyoxometalates with novel structure and outstanding oxygen reduction catalytic performance.The synthetic products were unique crystal with different coordination modes and structures.Through modification or bridging of organic pyridine nitrogen and the controls of the reaction temperature,reaction time,and the ratio of materials,three series of novel copper-decorated polyoxometalates were obtained.Using infrared spectroscopy（IR）,thermogravimetric（TG）,cyclic voltammetry（CV）,linear sweep voltammetry（LSV）,et al measurements analyzed the physical and electrical catalytic properties of the catalysts.This paper was divided into three parts.1.Two novel unreported copper-decorated isopolyoxovanadates have been successfully synthesized and characterized,Cu（bipy）[V₂O₆]（bipy=2,2’-bipyridine）（1）,Cu（bpyCOO）[V₂O₆]（bpyCOOH=4-（[2,2’:6’,2’’-terpyridin]-4’-yl）benzoic acid）（2）.In order to investigate their oxygen reduction catalytic activity,carbon black was used as a support to prepare a composite catalyst,and their oxygen reduction catalytic activity was initially determined by a rotating disk electrode（RDE）.The test results showed that both catalysts have good catalytic activity and guide the 4e^-transfer pathway in the oxygen reduction reaction.2.Three novel copper-decorated organic-inorganic hybrids based on Lindqvist-type tungstates were successfully synthesized by hydrothermal synthesis method.The structures of these hybrids were characterized and mixed with carbon black to form three novel carbon-loaded copper-decorated polyoxometalate catalysts,and their oxygen reduction performances were characterized through electrochemical analysis,it can be seen that all of the three catalysts have good oxygen reduction catalytic activity,and compound 3 has the best properties.3.A novel dianionic copper-decorated and phenanthroline-based polyoxometalate was successfully synthesized and characterized,{Cu（phen）₂}₂W₆O₁₉{Cu（phen）₂}₂V₄O₁₂（6）.It was loaded on carbon powder to study the catalyst’s oxygen reduction catalytic activity.The results showed that the catalyst has excellent electrocatalytic properties and dominates the 4e^-transfer process in the oxygen reduction reaction.