| With the depletion of fossil fuel and increasing environmental problems,people have a large number of study in sustainable clean energy.The electrocatalytic reaction provides a renewable cleaning energy source,but developing an efficient electrocatalyst becomes a current hot spot.The coordination compound is a compound formed by the coordination bones between a metal ions atoms and a organic molecule ligands.It has been widely studied in basic research and practical applications,because of the advantage of structure design and functional regulation.The coordination compounds have shown promising application in the field of electrocatalysis,but the precise synthesis of complexes and their thermal conversion mechanism are still not explained wellIn this thesis,a series of Co and Ni transition metal clusters and coordination compounds were designed by the reaction of 3d transition metal and Benzimidazole derivatives.The assembly process mechanism of clusters were proposed according to crystalline date and electrospray ionization mass spectrometry(ESI-MS).The thermal decomposition process of transition metal coordination compounds were detected by TG-MS to propose possible pyrolysis process.The resulting metal/C materials were applied in the electrocatalytic oxygen evolution reaction(OER),the catalytic activity of metal/C can be controlled by regulating the multi-metal doping.In the first chapter of introduction part,the coordination compound as the development status of the new material system in electrocatalysis is the development and application of mass spectrometry in the chemistry,especially in coordination chemistry are introduced.Based on the topics of the assembly mechanism of the coordination compounds and the application of electrocatalysis,importance of this thesis exhibitedIn the second chapter,the Co6 and Co5 clusters were firstly synthesized by solvent method in the presence of Co(NO3)2·6H2O and 2-mercaptophenylphenylmidazole.The structure of the two crystals was determined using a single crystal diffraction gauge,and the Co5 crystal was found to have better stability in the solution by pressurizing mass spectrometry.It is found that the Co6[(C9H8N2O)12](Co6)could be transformed into Co5(C9H7N2SNO)4(Co5)during reaction.It is found that the Co6 to Co5 was studied in detail in detail by ESI-MS.The transition mechanism.The structure of the two crystals was determined using a single crystal diffraction gauge,and the Co5 crystal was found to have better stability in the solution by pressurizing mass spectrometry.By temperature dependence spectrometry and TOPAS fitting,a possible assembly and transition mechanism of Co6 clusters to Co5 clusters of Co1Ls2?Co2Ls4?Co3Ls6?Co6Ls12 ? Co1LN1?Co2LN2?)Co5LN4 is proposed.In addition,a thiohydroximic acid organic molecular could be synthesized by this methodIn the third chapter,single and multi-metallic coordination compounds were synthesized by 1,2-bis(1-methyl-1H-benzo[d]imidazole-2-yl)ethan-1-ol)(L2)and transition metal ions such as Ni and Co ions.Then their thermal decomposition process and electrocatalytic performance were investigated.By using TG-MS,it was found that 17%of CoL2 remained after pyrolysis at 800?,At the same time,different proportions of Ni-Co,Ni-Zn bimetallic and Ni-Co-Zn multi-metallic doped compounds were synthesized by adjusting the temperature and metal salt ratio,which provides a good material basis for the controlled preparation of advanced multi-metallic electrocatalysts.The pyrolysis products of CoL2 and Ni1Co1L2 were characterized by TG-MS,SEM and EDS,and the possible pyrolysis mechanism has been studied.The pyrolysis products at different temperatures were tested by electrocatalytic OER.By comparison,it is found that Ni1Co1L2@NC-900 has a low electrochemical performance of 291 mV in an electrolyte solution of 1.0 M KOH and a current density of 10 mA/cm-2.In this way,the performance of carbon-based electrocatalysts can be regulated by a simple and controllable ML2 low nuclear compounds. |
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