Synthesis Of Copper-based Nanomaterials And Their Application In Electrocatalytic Reactions

Fuel cells are clean and efficient,and the development of high-performance electrocatalytic materials is a necessary way to promote the further development of fuel cells.In recent years,copper-based nanocatalysts have shown excellent application prospects in electrocatalysis.The platinum-copper composite electrocatalyst can effectively improve the electrocatalytic performance and reduce the amount of platinum in the catalyst.This paper focuses on the synthesis and characterization of PtCu alloy catalysts and their fuel cell-related oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR)electrocatalytic activity:1.Two different synthesis methods were used to obtain spherical and hollow nanocatalysts respectively,and the effects of the reaction time of Cu nanoparticles,platinum-copper input ratio and synthesis method on the catalyst structure and performance were investigated.Among them,it was found that PtCu nanoparticles synthesized by the two-step method can reduce the oxidation of Cu and expose more alloy crystal planes.In addition,it is found that the hollow-structure ptcu nanocatalyst has more excellent electrochemical activity.The introduction of cu can effectively adjust the electronic structure of Pt,thereby changing the adsorption energy of Pt to oxygen(or methanol),which is conducive to improving the catalytic activity of ORR and MOR.The results show that the low platinum hollow structure PtCu/C(PtCu-1/10)nanocatalyst has a mass activity of 0.55 Amgpt-1 at 0.9 V,which is 3.3 times that of commercial Pt/C;the activity is 1.26 mAcm-2 at 0.9 V,which is 3.7 times that of commercial Pt/C.Its higher mass activity and specific activity are attributed to the alloy effect of hollow structure PtCu/C(PtCu-1/10)nanoparticles and its special hollow structure.At the same time,during the methanol oxidation reaction,the PtCu/C(PtCu-1/5)catalyst showed strong electrocatalytic activity.The catalyst had a methanol oxidation reaction mass activity of 1.6 Amgpt-1 and the specific activity of 3.5 mAcm-2 at 0.59 V(vs.SCE),respectively 2.1 times and 1.5 times that of commercial Pt/C catalysts,and its stability is also superior to commercial Pt/C catalysts.2.Successfully synthesized PtCu alloy catalyst with polyhedral depression structure,PtCu alloy catalyst with frame structure and PtCu alloy catalyst with octahedral structure.Among them,the growth process of the PtCu alloy catalyst with a polyhedral depression structure was also explored.It was found that with the extension of the platinum source reduction time,the etching effect of PtCu nanoparticles became more obvious,and the morphology and size were more regular.In addition,the PtCu alloy catalyst with an octahedral structure exhibits excellent ORR performance,and its ORR performance is superior to commercial platinum-carbon catalysts.It shows that the catalyst with special structure is not only conducive to mass transfer but also can provide more active sites,which has great reference significance for the research of the catalysts.