Preparation And Related Properties Of New Spinel-type Compound

With oil and other non-renewable resources are depleted and other environmental issues,such as climate change,have become increasingly prominent,fuel cells,metal-air batteries and other green energy technology have received more and more attention.One of the key factors in this technique is the oxygen electrode,on which there occurs ORR and OER reactions,and the speed of the two reactions mainly depends on the electrode catalyst,so the catalyst will directly affect the development of green energy technologies.Currently the best ORR catalysts are Pt,but it’s expensive and has a poor OER catalytic performance,as a result,people put emphasis on dual-way catalysts,which are affordable,easy to get,and has a good catalytic performance in ORR and OER reactions at the same time.Spinel-type oxide is in line with this feature,so it becomes a hot spot of concern.There comes the main contents of this paper.(1)Explore the best preparation methods and conditions.With the use of ammonium oxalate co-precipitation,thermal decomposition of sodium nitrate,nitrate mixed calcination and sacrifice template method in sequence,while taking advantage of XRD,SEM,TEM and other methods to characterize the properties of the structure,we found that samples prepared by sacrifice template method with carbon spheres as templates had the smallest size and the best morphology,and then we determine the elements of the sample,element distribution,lattice structure and so on by XPS,EDS,structure refinement and other characterization methods.At last,we successfully prepared quaternary spinel-type transition metal oxide CoCuMnO4.(2)Electrochemical analysis.By use of electrochemical test system with three-electrode system,we examined the catalytic performance of the nano N-CoCuMnOx prepared by sacrifice template method,then analyzed the obtained results of cyclic voltammetry curves,polarization curves,K-L curves,stability curves and so on in contrast with the bulk P-CoCuMnOx and commercial Pt/C.In ORR process,whether nanoscale or micron scale,CoCuMnOx’s limiting current density is higher than or close to the commercial Pt/C,so good ORR catalytic properties would describe CoCuMnOx,especially nanoscale CoCuMnOx,whose performance was far better than the commercial Pt/C.In addition,by the calculation of the number of electron transfer through K-L curve,we found N-CoCuMnOx and commercial Pt/C are in the main four-electron process,showing the best performance for oxygen reduction.In OER aspect,for its lowest peak potential and the largest current density at the same potential,N-CoCuMnOx’s performance is also the best,proved a much better catalytic performance of OER than the commercial Pt/C.Finally,for stability,regardless of OER or ORR,N-CoCuMnOx’s performance is the best,especially in the ORR process,its current dropped only less than 10%after 10000s,far better than the commercial Pt/C.Preparation of this article is simple,low cost,and the product also showed excellent double effect of ORR and OER catalytic performance,have the potential to replace Pt catalyst,are likely to be put into large-scale commercial applications.