本文選題：電化學(xué)氧泵　切入點(diǎn)：雞蛋黃　出處：《天津大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：電化學(xué)氧泵(EOP)是一種基于空氣電極的電化學(xué)制氧裝置,可以在電位差的驅(qū)動(dòng)下將O_2從低濃度混合氣中分離出來。但目前基于質(zhì)子交換膜電解池的EOP動(dòng)力學(xué)緩慢且催化劑價(jià)格昂貴,而基于堿性電解液體系的EOP存在漏液、溶液碳酸化所導(dǎo)致的的電解質(zhì)結(jié)晶析出以及電解液浪費(fèi)等諸多問題。本文從基于生物質(zhì)的雙功能氧電極催化劑、高強(qiáng)度水凝膠電解質(zhì)膜和不同催化劑體系的電化學(xué)氧泵性能等方面對(duì)電化學(xué)氧泵進(jìn)行了研究。以雞蛋黃為前驅(qū)體,經(jīng)一步熱解法在熔融鹽介質(zhì)中制備了雜原子摻雜碳(HDC)材料電催化劑,其中原位摻雜的N含量最高可達(dá)5.89 wt.%,并摻雜有少量的P和S,XPS測(cè)試結(jié)果表明N原子多以Graphitic-N和Pyridinic-N形式摻雜到碳骨架中。使用循環(huán)伏安法、線性掃描伏安法以及計(jì)時(shí)電流法等測(cè)試方法在旋轉(zhuǎn)圓盤電極上對(duì)HDC催化劑電催化性能進(jìn)行了表征,結(jié)果表明800℃下熱解制備的HDC催化劑的氧還原反應(yīng)催化活性與商品Pt/C催化劑相當(dāng),而析氧反應(yīng)催化活性和穩(wěn)定性則優(yōu)于Pt/C催化劑。向蛋黃前體中加入六水合氯化鈷可使制得的HDC由疏松的不規(guī)則片層狀結(jié)構(gòu)變?yōu)楹写罅坎灰?guī)則泡孔的海綿狀結(jié)構(gòu),并在孔內(nèi)沉積Co_2P納米顆粒。這種獨(dú)特的催化劑結(jié)構(gòu)有效地提高了其ORR催化活性和OER穩(wěn)定性。以丙烯酰胺和聚乙烯醇為交聯(lián)前體,采用預(yù)混式兩步交聯(lián)法制備了一種具有較高抗拉強(qiáng)度的聚丙烯酰胺/聚乙烯醇(PAM/PVA)雙網(wǎng)絡(luò)水凝膠。采用該方法可使兩級(jí)網(wǎng)絡(luò)前體在交聯(lián)成型前預(yù)混均勻,提高水凝膠的結(jié)構(gòu)均一性。以該方法制得的水凝膠具有極疏松的互通式孔洞結(jié)構(gòu),彈性模量可達(dá)50 kPa以上,拉伸斷裂應(yīng)力可達(dá)113.4 kPa。對(duì)該水凝膠進(jìn)行堿摻雜,制得了電導(dǎo)率高達(dá)10~(-2) S·cm~(-1)數(shù)量級(jí)的堿摻雜水凝膠電解質(zhì)膜,電化學(xué)穩(wěn)定窗口可達(dá)2.0 V左右,有望作為固體電解質(zhì)膜應(yīng)用于燃料電池和電化學(xué)氧泵等電化學(xué)裝置中。分別以貴金屬催化劑(20 wt.%Pt/C為陰極催化劑,銥黑為陽(yáng)極催化劑)、自制的HDC催化劑和自制的Co_2P-HDC催化劑為電極催化劑,進(jìn)行了電化學(xué)制氧的研究,所用電解質(zhì)為自制的堿摻雜PAM/PVA雙網(wǎng)絡(luò)水凝膠電解質(zhì)膜。其中以Co_2P-HDC作為電極催化劑的電解起始電壓為0.587 V,在1.0 V電解電壓下運(yùn)行1 h后電流保持率為62%,在50 mA·cm~(-2)的低電流密度下運(yùn)行時(shí)的電壓升高速率僅為2.66 mV·h~(-1),表現(xiàn)出比貴金屬催化劑氧泵更優(yōu)的性能。
[Abstract]:Electrochemical oxygen pump (EOPP) is an electrochemical oxygen generator based on air electrode. O _ s _ 2 can be separated from low concentration mixture driven by potential difference, but the kinetics of EOP based on proton exchange membrane electrolysis cell is slow and the cost of catalyst is expensive, while EOP based on alkaline electrolyte system has leakage. In this paper, the bifunctional oxygen electrode catalyst based on biomass is used to solve the problems of electrolyte crystallization and electrolyte waste caused by carbonation of solution. The electrochemical oxygen pump properties of high strength hydrogel electrolyte membrane and different catalyst systems were studied. In this paper, a one-step pyrolysis method was used to prepare hetero-atom doped carbon-doped HDC-based electrocatalysts in molten salt medium. The content of N in situ doping can reach 5.89 wt.In addition, a small amount of P and Schi-XPS results show that N atoms are mostly doped into the carbon skeleton in the form of Graphitic-N and Pyridinic-N, and cyclic voltammetry is used. The electrocatalytic properties of HDC catalysts were characterized by linear scanning voltammetry and chronoamperometric method on rotating disk electrodes. The results show that the catalytic activity of HDC catalyst prepared by pyrolysis at 800 鈩，

本文編號(hào)：1583435