Template Preparation And Catalytic Performance Investigation Of High Efficiency Catalysts

Oxygen reduction reaction?ORR?and oxygen evolution reaction?OER?are important electrode reactions for fuel cells,metal-air batteries,and electrolyzed water.Traditional precious metal ORR?Pt/C?and OER?RuO₂?catalysts have limited their widespread use due to cost and other factors,so developing suitable ORR and OER catalysts is key to commercializing these clean energy devices.Carbon-based transition metal composites are an important class of electrocatalysts.Therefore,in this paper,a series of catalysts were synthesized based on carbon-based materials and using excessive metals as active sites.The special work is as follows:The zinc oxide nanowires were prepared by hydrothermal method,used as a template,the surface was loaded with ZIF-8,and then calcined to obtain carbon nanotubes?CNTs?.The CNTs exhibits excellent ORR catalytic performances.In order to further expand the synthesis method,dopamine is polymerized on the surfaces of the zinc oxide nanowire,and the nitrogen-doped carbon nanotubes catalyst can also be obtained.The catalyst exhibits an excellent ORR catalytic performance and close to Pt/C and has a certain catalytic hydrogen evolution performance.In order to further improve the catalytic performance of the above catalyst,in the process of loading dopamine on zinc oxide nanowires,we added iron salts to the solution,and then the catalysts can be obtained by calcination in an ammonia atmosphere.The iron nitride-modified carbon nanotubes?FeN_x/CNT-NH₃?catalysts showed excellent ORR catalytic performance in acidic,basic and neutral electrolytes,which is an ORR catalyst that is active over a wide pH range.In order to further optimize the structure of the catalyst,we used 2-amino terephthalic acid as ligand.The Zn-MOF was obtained by self-assembly of zinc oxide nanowires and 2-aminoterephthalic acid,and calcined to obtain nitrogen-doped hollow carbon spheres ?NHCSs?.The Fe₃O₄/NHCSs catalyst was obtained by supporting the Fe₃O₄ active site on the NHCSs,and exhibited excellent ORR catalytic activity at 0.1 M KOH,and exhibited excellent battery performance on a self-made Zinc-Air battery.The preparation process of this experiment is simple,and it is carried out at temperature,which requires less energy,and provides a new idea for synthesizing carbon spheres of similar structure.The V₂O₅ nanowires were prepared by hydrothermal method,and then V₂O₅ nanowires were used as template and a vanadium source.The surface was loaded with ZIF-67,calcined in a nitrogen atmosphere,and the calcination temperature was changed to obtained vanadium-modified Co containing oxygen holes.The carbon rods of vanadium-modified Co/CoO containing oxygen holes exhibits good oxygen performance,and only 320 mV overpotential can regenerate 10 mA/cm² current density in 1 M KOH.