本文關(guān)鍵詞：微生物燃料電池空氣陰極催化劑的制備及其產(chǎn)電性能研究　出處：《江西師范大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 微生物燃料電池 空氣陰極 催化劑 摻雜 纖維素 氧氣還原

【摘要】：微生物燃料電池（MFC）是一種綠色能源新技術(shù)。它利用微生物的新陳代謝，氧化有機物將化學(xué)能轉(zhuǎn)化為電能，在廢水處理方面具有巨大的應(yīng)用潛力。空氣陰極式MFC直接以氧氣為電子受體，，是公認的最有應(yīng)用前景的構(gòu)型之一�？諝怅帢O材料，特別是氧氣還原（ORR）催化劑，成為MFC應(yīng)用的關(guān)鍵因素之一。 目前MFC的空氣陰極催化劑存在價格昂貴、制備過程復(fù)雜以及長期穩(wěn)定性差等問題，制約了其規(guī)�；瘧�(yīng)用。本文基于可再生的纖維素基材料，采用簡單易行的方法制備了三種高效廉價的碳基ORR催化劑，以推動MFC在廢水處理領(lǐng)域的應(yīng)用。本文研究內(nèi)容包括以下三部分： （1）以天然植物稻草秸稈為原料，采用直接碳化的方法制備ORR催化劑。采用輥壓法制備空氣陰極，考察了催化層粘結(jié)劑用量對電池性能的影響，并和炭黑催化劑對比。實驗結(jié)果表明，植物源ORR碳催化劑的空氣陰極電化學(xué)性能比炭黑更優(yōu)。催化層中粘結(jié)劑的用量對空氣陰極的性能影響較大，當催化劑和粘結(jié)劑PTFE的質(zhì)量比為4時，MFC的產(chǎn)電性能最佳。其電壓輸出最高達0.558V，最大功率密度為1058mW/m2。增大粘結(jié)劑PTFE的用量，如空氣陰極3#，最大功率密度降至790mW/m2。因為，過多的粘結(jié)劑一方面會覆蓋部分ORR催化劑活性位點、阻礙質(zhì)子傳遞等；另一方面，增大電極內(nèi)阻。但是粘結(jié)劑用量過少，電極易出現(xiàn)脫落現(xiàn)象。因此，最優(yōu)粘結(jié)劑用量為：催化劑和PTFE質(zhì)量比為4。 （2）以商業(yè)化的磷酸纖維素為原料，采用直接碳化的方法制備磷摻雜碳ORR催化劑。在上一章節(jié)已優(yōu)化的輥壓工藝參數(shù)下，將磷摻雜碳ORR催化劑制備成空氣陰極，研究了其在MFC的性能，并對制備的催化劑做了一系列材料學(xué)表征�？諝怅帢O線性伏安掃描結(jié)果表明，與未摻雜碳相比，磷摻雜碳催化劑能夠明顯地提高空氣陰極電化學(xué)性能。電池性能測試結(jié)果顯示，1000℃條件下制備的催化劑性能最優(yōu)，電池穩(wěn)定電壓輸出達0.6V，最大功率密度達1312mW/m2，是未摻雜催化劑的近3倍，也高于同體系下的Pt催化劑（1226mW/m2）。雜原子磷在碳催化劑骨架中的成功摻雜，極大地提高了MFC的產(chǎn)電性能。這是首次通過直接碳化的方式制備磷摻雜碳，具有無毒、成本低、易放大等優(yōu)點，作為MFC催化劑具有巨大的潛力。 （3）以天然可再生的纖維素為碳源，以廉價無毒的無機鹽(NH4)3PO4為氮源和磷源，成功地制備了一種新型的氮磷共摻雜的碳材料（PNC）。將其作為ORR催化劑制備成空氣陰極，構(gòu)建MFC，研究MFC的產(chǎn)電性能。線性伏安掃描結(jié)果表明，PNC具有優(yōu)異的ORR催化性能。900℃下制備的PNC-900的MFC電壓輸出達0.636V，最大功率密度達2288mW/m2，比同體系下含Pt/C催化劑（1661mW/m2）更高。同時與氮摻雜或磷摻雜的碳材料相比，氮磷共摻雜具有更優(yōu)的ORR催化性能。催化劑的XPS表征顯示，N、P原子成功的摻雜入碳骨架中，氮磷共摻雜的協(xié)同效應(yīng)更進一步挺高了碳材料的ORR催化性能。
[Abstract]:Microbial fuel cell (MFC) is a new green energy technology that uses microbial metabolism to oxidize organic matter to convert chemical energy into electricity. Air cathode type MFC is considered as one of the most promising configurations with oxygen as its electron acceptor. Air cathode materials are widely used in wastewater treatment. In particular, oxygen reduction catalyst has become one of the key factors in the application of MFC. At present, the air cathode catalyst of MFC has some problems, such as high price, complex preparation process and poor long-term stability, which restrict its large-scale application. This paper based on renewable cellulosic materials. In order to promote the application of MFC in wastewater treatment, three kinds of carbon-based ORR catalysts with high efficiency and low cost were prepared by a simple and easy method. The ORR catalyst was prepared by direct carbonization and the air cathode was prepared by roller pressing method. The effect of binder content of catalyst layer on the performance of the battery was investigated. 1) using natural straw straw as raw material, the direct carbonization method was used to prepare ORR catalyst and the air cathode was prepared by roller pressing method. Compared with carbon black catalyst, the experimental results show that the electrochemical performance of ORR carbon catalyst is better than that of carbon black, and the amount of binder in catalyst layer has great influence on the performance of air cathode. When the mass ratio of catalyst to binder PTFE is 4:00, the electrical performance is the best, and the output voltage is up to 0.558 V. The maximum power density is 1058mW / m2. By increasing the amount of binder PTFE, such as the air cathode 3#, the maximum power density drops to 790mW / m2. On the one hand, too much binder will cover some active sites of ORR catalyst and block proton transfer. On the other hand, the internal resistance of the electrode is increased. However, if the amount of binder is too small, the electricity will fall off easily. Therefore, the optimal amount of binder is: the mass ratio of catalyst to PTFE is 4. (2) Phosphorus-doped carbon (ORR) catalysts were prepared from commercial cellulose phosphate by direct carbonization under the optimized roll pressing process parameters in the previous chapter. Phosphorus-doped carbon (ORR) catalysts were prepared into air cathodes and their properties in MFC were studied. A series of material characterization was carried out. The results of linear voltammetry showed that the air cathodes were linear. Compared with undoped carbon, phosphorus-doped carbon catalyst can obviously improve the electrochemical performance of air cathode. The results of battery performance test show that the catalyst prepared at 1000 鈩

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