本文選題：電化學(xué)氫泵反應(yīng)器 + 非均相催化加氫　； 參考：《大連理工大學(xué)》2016年碩士論文

【摘要】：近年來(lái),生物質(zhì)作為可持續(xù)能源受到廣泛關(guān)注,越來(lái)越多的研究集中于其提質(zhì)流程中的加氫過(guò)程。而電化學(xué)氫泵反應(yīng)器具有在陰極催化劑表面生成原位吸附氫的特殊結(jié)構(gòu),可使加氫過(guò)程在常溫常壓下進(jìn)行,避免了傳統(tǒng)加氫反應(yīng)器中高溫高壓操作帶來(lái)的一系列設(shè)備和操作復(fù)雜性。但是目前電化學(xué)氫泵加氫反應(yīng)器的氫源為純氫或水,純氫高昂的價(jià)格和水電解的巨大電能消耗,阻礙電化學(xué)氫泵加氫反應(yīng)器的進(jìn)一步發(fā)展。本文提出脫氫與加氫耦合的電化學(xué)氫泵雙反應(yīng)器解決上述難題,即利用電化學(xué)氫泵反應(yīng)器中質(zhì)子交換膜的分隔作用,使脫氫反應(yīng)與加氫反應(yīng)同時(shí)在陽(yáng)、陰極進(jìn)行且互不影響,陽(yáng)極有機(jī)物脫氫產(chǎn)生的H+通過(guò)質(zhì)子交換膜傳遞至陰極催化劑表面,直接供給陰極加氫。與水做氫源相比,有機(jī)物具有較低的電化學(xué)窗口,可降低脫氫電勢(shì)和供氫能源成本；脫氫與加氫在同一反應(yīng)器中完成,提升了反應(yīng)器的整體效率、降低設(shè)備成本�；陔娀瘜W(xué)氫泵雙反應(yīng)器的設(shè)想,本文嘗試了異丙醇-苯酚雙反應(yīng)器。陽(yáng)極異丙醇在常用陽(yáng)極催化劑Pt催化下脫氫生成氫氣和丙酮,通過(guò)改進(jìn)實(shí)驗(yàn)條件使脫氫電勢(shì)穩(wěn)定在0.85 V。并考察了生物質(zhì)模型化合物苯酚在電化學(xué)氫泵反應(yīng)器的加氫反應(yīng),環(huán)已醇選擇性可達(dá)95.4%,加氫速率達(dá)到17.0 nmol cm-2 s-1。在此基礎(chǔ)上,成功運(yùn)行Pt-Nafion-Pt異丙醇-苯酚雙反應(yīng)器,陰極苯酚加氫反應(yīng)速率9.7 nmol cm-2 s-1,陽(yáng)極電勢(shì)約為0.9 V。進(jìn)而,本文針對(duì)上述反應(yīng)器存在陽(yáng)極過(guò)電勢(shì)高,環(huán)已酮產(chǎn)率低的問(wèn)題進(jìn)一步改進(jìn)。陽(yáng)極通過(guò)使用PtRu催化劑,增大催化劑擔(dān)載量,脈沖電流以及操作條件優(yōu)化,將異丙醇脫氫電勢(shì)進(jìn)一步降低至0.2 V,并可長(zhǎng)時(shí)間穩(wěn)定運(yùn)行,僅為同條件下水脫氫電勢(shì)的1-10。同時(shí)以苯酚加氫得到更多環(huán)已酮為目標(biāo),改用Pd催化劑并進(jìn)行進(jìn)一步優(yōu)化,優(yōu)選擴(kuò)散層、催化劑擔(dān)載量、操作條件等,其在80℃時(shí),催化加氫生成環(huán)已酮速率達(dá)11.0 nmolcm-2 s-1,高于文獻(xiàn)報(bào)道的Pd-C催化的三相反應(yīng)速率。并成功運(yùn)行PtRu-Nafion-Pt/Pd異丙醇-苯酚雙反應(yīng)器,其中PtRu-Nafion-Pt反應(yīng)器陰極加氫速率達(dá)到19.3 nmol cm-2 s-1,陽(yáng)極電勢(shì)可穩(wěn)定在0.2 V,證明雙反應(yīng)器的可行性和精確控制反應(yīng)的優(yōu)勢(shì)。針對(duì)前文陰極苯酚滲透導(dǎo)致脫氫電勢(shì)升高問(wèn)題,探究了另一種生物質(zhì)模型化合物乙酰丙酸在電化學(xué)氫泵陰極的加氫反應(yīng),實(shí)驗(yàn)表明PtRu催化乙酰丙酸加氫的活性高于Pt。乙二醇作為陽(yáng)極反應(yīng)物,其相比異丙醇,可提供較高的電流密度,80℃可達(dá)到130 mAcm-2。并進(jìn)一步成功運(yùn)行PtRu-Nafion-Pt/PtRu乙二醇-乙酰丙酸雙反應(yīng)器,其陰極加氫反應(yīng)速率均高于單獨(dú)氫泵反應(yīng)器的加氫速率,整個(gè)過(guò)程中電壓持續(xù)穩(wěn)定在0.5 V。
[Abstract]:In recent years, biomass as a sustainable energy has received extensive attention, and more and more research has focused on the hydrogenation process in the process of improving the quality of biomass.The electrochemical hydrogen pump reactor has a special structure of in-situ hydrogen adsorption on the surface of the cathode catalyst, which can make the hydrogenation process take place at room temperature and atmospheric pressure.A series of equipment and operation complexity caused by high temperature and high pressure operation in traditional hydrogenation reactor are avoided.But at present the hydrogen source of electrochemical hydrogen pump hydrogenation reactor is pure hydrogen or water. The high price of pure hydrogen and the huge electric energy consumption of water electrolysis hinder the further development of electrochemical hydrogen pump hydrogenation reactor.In this paper, an electrochemical hydrogen pump dual reactor coupled with dehydrogenation and hydrogenation is proposed to solve the above problem, that is, by using the separation of proton exchange membrane in the electrochemical hydrogen pump reactor, the dehydrogenation reaction and the hydrogenation reaction are carried out simultaneously in the positive, cathode and without influence on each other.The H produced by the dehydrogenation of anodic organic compounds is transferred to the surface of the cathode catalyst through the proton exchange membrane and directly supplied to the cathode hydrogenation.Compared with water as hydrogen source, organic compounds have lower electrochemical window, which can reduce the potential of dehydrogenation and the cost of hydrogen supply energy, and the dehydrogenation and hydrogenation are completed in the same reactor, which improves the overall efficiency of the reactor and reduces the equipment cost.Based on the assumption of electrochemical hydrogen pump dual reactor, this paper tries to use isopropanol-phenol dual reactor.Anodic isopropanol was dehydrogenated to produce hydrogen and acetone under the catalysis of common anode catalyst Pt. The potential of dehydrogenation was stabilized at 0.85 V by improving the experimental conditions.The hydrogenation of phenol, a biomass model compound, in an electrochemical hydrogen pump reactor was investigated. The selectivity of cyclohexanol was 95.4 and the hydrogenation rate was 17.0 nmol cm-2 s-1.On this basis, the Pt-Nafion-Pt isopropanol-phenol dual reactor was successfully operated. The reaction rate of cathodic phenol hydrogenation was 9.7 nmol cm-2 s-1, and the anode potential was about 0.9 V.Furthermore, the problems of high anode overpotential and low cyclohexanone yield in the above reactors are further improved.By using PtRu catalyst, the catalyst load, pulse current and operation conditions were optimized to further reduce the dehydrogenation potential of isopropanol to 0.2V and to run stably for a long time, which was only 1-10 of the dehydrogenation potential in water under the same conditions.At the same time, more cyclohexanone was obtained by hydrogenation of phenol, PD catalyst was used and optimized, diffusion layer was selected, catalyst loading capacity, operating conditions, etc., at 80 鈩，

本文編號(hào)：1734633