發(fā)布時間：2018-03-28 22:31

  本文選題：聚苯胺　切入點：功能化　出處：《重慶大學(xué)》2015年碩士論文

【摘要】：直接甲醇燃料電池(DMFC)擁有高的能量轉(zhuǎn)換效率,燃料廉價易得,環(huán)境污染少,操作簡便等優(yōu)點,使得其在小型的可移動電源和微型電源等方面具備不可想象的應(yīng)用前景。然而,如何提高陽極催化劑的電催化性能是DMFC發(fā)展的一個挑戰(zhàn)。當(dāng)前,鉑(Pt)催化劑是研究最多的一種DMFC陽極催化劑。但是,此種Pt催化劑存在一個非常致命的缺陷:在甲醇的電催化氧化過程當(dāng)中,Pt催化劑的電催化氧化的活性以及穩(wěn)定性均比較低。選取合適的催化劑載體是制備出高性能Pt催化劑的最重要途徑。本論文發(fā)明了一種新型的Pt催化劑載體,并考察了其對Pt催化劑性能提高的影響。本文第一次用聚苯胺(PANI)修飾混合催化劑載體二氧化鈦-炭黑(Ti O2-C)以進一步提高Pt/二氧化鈦-炭黑(Pt/Ti O2-C)對甲醇的電催化氧化的活性以及穩(wěn)定性。首先,我們采用原位聚合法,用過硫酸銨(APS)作為氧化劑、硫酸(H2SO4)作為摻雜劑使苯胺(An)單體聚合反應(yīng)合成聚苯胺(PANI);然后通過浸漬-還原法,用甲酸(HCOOH)來還原氯鉑酸(H2Pt Cl6·6H2O),使Pt納米顆粒沉積在混合催化劑載體Ti O2-C上。循環(huán)伏安曲線(CV)和計時電流曲線表征了所制備的催化劑對于甲醇的電催化氧化的活性以及穩(wěn)定性,結(jié)果表明,與Pt/Ti O2-C催化劑相比,Pt-PANI/Ti O2-C催化劑對于甲醇具有更高的電催化氧化的活性以及穩(wěn)定性。紅外光譜(FT-IR)、X-射線衍射(XRD)、能譜(EDS)以及透射電子顯微鏡(TEM)等測試方法對催化劑進行了物理表征,證實了PANI的存在能夠顯著地提高Pt納米顆粒的分散性,使其具有更窄的粒徑分布。X射線光電子能譜(XPS)表明了Pt納米顆粒與PANI之間確實有電子效應(yīng)的存在,此電子效應(yīng)的存在使得Pt-PANI/Ti O2-C催化劑對于甲醇的電催化氧化具有更高的穩(wěn)定性。與此同時,本文還優(yōu)化了Pt-PANI/Ti O2-C催化劑的制備工藝,當(dāng)Ti O2在混合催化劑載體Ti O2-C中的含量為40%,An的用量為30%,An與APS的摩爾比nAn:nAPS為1:1,H2SO4的濃度為1.0 mol L-1時,Pt-PANI/Ti O2-C催化劑對甲醇具備最好的電催化氧化的活性以及穩(wěn)定性。此外,本文還對比研究了Pt-PANI/Ti O2催化劑和Pt-PANI/C催化劑對于甲醇的電催化氧化的活性以及穩(wěn)定性,結(jié)果表明,當(dāng)用Ti O2作為催化劑的載體時所制備的Pt-PANI/Ti O2催化劑,其對甲醇的電催化氧化的活性低于用C作為催化劑的載體時所制備出的Pt-PANI/C催化劑,但其穩(wěn)定性卻高于Pt-PANI/C催化劑。
[Abstract]:Direct methanol fuel cell (DMFC) has the advantages of high energy conversion efficiency, cheap fuel, low environmental pollution, easy operation and so on, which makes it have unimaginable application prospect in small movable power supply and micro power supply. How to improve the electrocatalytic performance of the anode catalyst is a challenge for the development of DMFC. At present, the platinum Ptcatalyst is one of the most studied DMFC anode catalysts. This kind of Pt catalyst has a very fatal defect: the activity and stability of Pt catalyst are low during the electrocatalytic oxidation of methanol. This paper presents a new type of Pt catalyst carrier. The effect on the performance of Pt catalyst was also investigated. In this paper, the electrocatalytic oxygen of methanol was further improved by using Polyaniline (pani) modified mixed catalyst carrier titania-carbon black TIO _ 2-C) to further improve the catalytic activity of Pt/ titanium dioxide / carbon black Pt- TIO _ 2-C for methanol. Chemical activity and stability. First, Polyaniline was synthesized by in situ polymerization with ammonium persulfate (APS) as oxidant and aniline anion (aniline) monomer as dopant, and then the Polyaniline was synthesized by impregnation-reduction method. HCOOH) was used to reduce H _ 2Pt Cl6 _ 6H _ 2O, Pt nanoparticles were deposited on TIO _ 2-C mixed catalyst carrier. Cyclic voltammetry curves and chronoelectric current curves were used to characterize the activity and stability of the catalysts for methanol oxidation. The results show that. Compared with Pt/Ti O2-C catalyst, Pt-PANIR / TiO2-C catalyst has higher activity and stability for methanol oxidation. The catalyst was characterized by FTIR, EDS-X ray diffraction and transmission electron microscopy (TEM), etc. The results show that the catalytic activity of Pt-PANIR / TiO2-C catalyst is better than that of Pt-PANIR / TiO2-C catalyst, and the catalytic activity is better than that of Pt-PANIR / TiO2-C catalyst. It is proved that the existence of PANI can significantly improve the dispersion of Pt nanoparticles and make them have a narrower particle size distribution. X-ray photoelectron spectroscopy (XPS) shows that there is an electron effect between Pt nanoparticles and PANI. The existence of this electron effect makes the Pt-PANI/Ti O 2-C catalyst more stable for the electrocatalytic oxidation of methanol. At the same time, the preparation process of Pt-PANI/Ti O 2-C catalyst is optimized. When the content of TIO _ 2 in TIO _ 2-C is 40 and the amount of an is 30, the molar ratio of an to APS is 1: 1, H _ 2SO _ 4 is 1.0 mol L ~ (-1), the Pt-PANI- / TIO _ 2-C catalyst has the best electrocatalytic activity and stability for methanol oxidation. The activity and stability of Pt-PANI/Ti O 2 catalyst and Pt-PANI/C catalyst for methanol oxidation were compared. The results showed that the Pt-PANI/Ti O 2 catalyst was prepared when TIO 2 was used as the support of the catalyst. The activity of electrocatalytic oxidation of methanol was lower than that of Pt-PANI/C catalyst prepared with C as catalyst, but its stability was higher than that of Pt-PANI/C catalyst.
【學(xué)位授予單位】：重慶大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：O643.36;TM911.4

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本文編號：1678386