The Studies Of Non-Noble-Metal ORR Catalyst From Pyrolyse Pig Blood

Fuel cells has the advantages of high efficiency, little pollution, easy to start and soon, and are considered to be the fourth generation of green energy power and the mostpromising technology to provide power. The catalysts are the key component of fuelcells, and nowadays, the noble metal Pt is the main catalyst for the oxygen reductionreaction (ORR). But the cost of Pt is too high to limit the large-scale promotion andapplication of fuel cells. Therefore, to prepare the catalyst which has low cost and goodcatalytic activity for oxygen reduction reaction (ORR) is one of the key to solve theproblems. And the TM-N/C catalyst (TM is non-precious transition metal) is gettingmore and more attention. But in the traditional method of preparing ORR catalyst, thecost the transition metal macrocycles is also high. In this thesis, the very inexpensivepig blood is used as raw material, through the process of heat treatment to prepare theTM-N/C catalyst for ORR.At first, the pig blood was heated at120℃to remove the water and obtained theprecursor, and then used two-step heating method to prepare ORR catalyst. The effect ofinitial temperature, initial treatment time, final temperature and initial treatment time onthe catalytic activity were investigated in this work. The performance and stability ofelectro-catalytic for ORR were evaluated by linear sweep voltammetry, And thesuperficial characteristics of the catalyst is characterized by TG/DTA、XRD and EDXR.The results shows that initial temperature, initial treatment time, final temperatureand treatment time will influence the catalytic activity of the catalysts which preparedby pig blood. The best condition in this work is that: initial temperature200℃, initialtreatment time1h, final temperature800℃, initial treatment time2h. The choice oftemperature agreed with the TG/DTA. The onset reduction potential of the catalystwhich prepared by the best condition is0.51V (vs.SCE).The result of XRD showed that under the optimal conditions，the characteristicpeak of KFeO2in catalyst samples decreases, and the Fe2O3characteristic peaksappeared. but the blood contains a variety of complex elements, so the catalytic activesite still required further research. EDXRF showed that Fe content is high in catalyst,which concluded Fe content are important factors of the catalyst activity. By adding Feelements to study the effect of Fe content on the catalyst performance, and resultsshowed that the effect is significant, a small amount of Fe adding improved the catalyst performance, and Fe overdose will reduce that performance.The catalyst effect of other heat treatment systems are also investigated in thisthesis, the results showed that different heat treatments appeared different catalyticeffects due to the different forming process. There is a larger optimization space of heattreatment for preparing pig-blood catalyst.