發(fā)布時(shí)間：2018-01-12 09:21

  本文關(guān)鍵詞：一維CoO_x納米結(jié)構(gòu)原位負(fù)載電催化膜制備及催化氧化性能研究　出處：《天津工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 苯甲醇 苯甲酸 電催化氧化 電催化膜反應(yīng)器 一維鈷基金屬氧化物

【摘要】：開發(fā)綠色高效、高選擇性的苯甲酸合成體系是精細(xì)化學(xué)品生產(chǎn)的重點(diǎn)研究方向。針對(duì)工業(yè)上制備苯甲酸中腐蝕污染嚴(yán)重、產(chǎn)物難分離、操作復(fù)雜等問題。本文以管式微孔鈦膜為基膜,采用水熱熱解法原位負(fù)載一維CoOx納米結(jié)構(gòu),構(gòu)筑三維CoOx/Ti電催化膜電極。對(duì)膜電極的微觀形貌、晶形結(jié)構(gòu)及電化學(xué)性能進(jìn)行表征分析,結(jié)構(gòu)表明一維CoOx納米線原位負(fù)載基體鈦膜提高了催化劑與膜之間的相互作用力,大大提高了膜電極的活性面積、降低膜與溶液之間的電子傳輸阻力。以CoOx/Ti電催化膜電極為陽極,不銹鋼網(wǎng)為陰極,構(gòu)建電催化膜反應(yīng)器(ECMR)。通過調(diào)控膜反應(yīng)器操作參數(shù)和反應(yīng)條件可控高效催化氧化苯甲醇制備苯甲酸。在最優(yōu)操作條件下,反應(yīng)溫度為21℃,電流密度為2.6 mA cm-2,停留時(shí)間為14 min,pH為13.9時(shí),苯甲醇濃度為10 mmol L-1,電解質(zhì)NaOH濃度為0.125 mol L-1條件下,苯甲醇的轉(zhuǎn)化率大于99%,苯甲酸的選擇性為92%。ESR結(jié)果證實(shí),Co基電催化膜電極在低壓電場(chǎng)激發(fā)下,可以產(chǎn)生高活性的羥基自由基,由此實(shí)現(xiàn)鈷元素價(jià)態(tài)由低價(jià)態(tài)向高價(jià)態(tài)相互轉(zhuǎn)變及基膜與一維CoOx納米線相互作用進(jìn)而實(shí)現(xiàn)苯甲醇的氧化,通過電催化氧化反應(yīng)與膜分離一體化實(shí)現(xiàn)可控高效、高選擇性制備苯甲酸。此外,對(duì)比膜電極形貌效應(yīng)對(duì)電催化性能影響,制備了一維CoOx納米線、一維CoOx納米針及零維CoOx納米顆粒負(fù)載基體鈦膜,并構(gòu)建電催化膜反應(yīng)器用于降解含酚廢水。結(jié)果表明,在常溫常壓下,電解質(zhì)Na2SO4濃度為14.4gL-1,pH值為7.0,苯酚初始濃度為470 mg L-1,電流密度為1.0 mAcm-2,停留時(shí)間為14 min。納米針膜反應(yīng)器降解苯酚效果最佳,其COD和TOC去除率分別為88.6%及73.8%。
[Abstract]:The development of green, efficient and highly selective benzoic acid synthesis system is the key research direction of fine chemical production. In view of the serious corrosion pollution in the industrial preparation of benzoic acid, it is difficult to separate the products. In this paper, the tubular microporous titanium film was used as the base film, and the in-situ loading of one-dimensional CoOx nanostructures was investigated by hydrothermal method. Three-dimensional CoOx/Ti electrocatalytic membrane electrode was constructed. The microstructure, crystal structure and electrochemical properties of the membrane electrode were characterized and analyzed. The structure shows that the in-situ loading of titanium film on one-dimensional CoOx nanowires increases the interaction force between the catalyst and the membrane, and greatly increases the active area of the membrane electrode. CoOx/Ti electrocatalytic membrane electrode was used as anode and stainless steel mesh as cathode. An electrocatalytic membrane reactor (ECM) was constructed to prepare benzoic acid from benzyl alcohol by controlling the operating parameters and reaction conditions of the membrane reactor. Under the optimum operating conditions, the reaction temperature was 21 鈩，

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