Study On Synthesis Of Biomass-based Carbon Materials And Oxygen Reduction Performance

Nowadays,energy crisis and environmental pollution are increasingly serious.Thus,developing a new kind of energy is of great significance to the development of human society.Due to the merits of high energy conversion rate and green environmental protection,fuel cells have been widely studied.However,oxygen reduction reaction(ORR)which controls the performance of fuel cells at the cathode is sluggish.Thus,catalysts are needed to catalyze the process of ORR.Traditionally,requiring the lowest overpotential,platinum(Pt)is capable of completing this four-electron ORR process and has long acted as a reasonable catalyst for ORR.However,it still suffers from low long-term durability and susceptibility to methanol deactivation.The high cost and scarcity of Pt catalysts,in particular,limit large-scale commercial application of fuel cells significantly.Therefore,considerable efforts have been made to develop a cheap,efficient and stable alternative for Pt and Pt-based catalysts to tackle energy crisis and environmental pollution.Carbon materials with excellent performance have been in the spotlight.In particular,nitrogen doping to carbon materials is inclined to increase active sites and improve catalytic activity.Most importantly,not only can biomass be used as a source of carbon,but also used as a source of nitrogen.Therefore,the research on biomass in the field of electrochemistry has attracted much attention.This work mainly adopts a method of cheap,simple and environmental friendly to prepare a biomass-based carbon catalyst and study it's oxygen reduction reaction performance.The main research content includes the following several aspects:(1)Using bamboo as raw material and adopting a method of direct pyrolysis in nitrogen atmosphere to obtain nitrogen-doped carbon catalysts(2)Using lotus leaves as raw material and studying catalytic activity of lotus leaves-based nitrogen doped carbon catalyst.(3)Based on lotus leaf,Preparing N,P co-doped carbon catalysts with desirable catalytic activity by direct high temperature annealing process.H3PO4 is used as the source of P and lotus leaves as the source of C and N.The part is based on the previous research part,aiming to further improve the catalyst performance.Bamboo leaves-based and lotus leaves-based nitrogen self-doped carbon catalyst are likely to be employed for oxygen reduction reaction in alkaline medium.SEM,BET,XRD and XPS characterization methods were used,respectively.RDE and RRDE electrochemical methods are used to test the ORR activity.The experimental results show that the biomass-based carbon catalyst has excellent catalytic activity and methanol resistance and stability.