整裝金屬纖維結(jié)構(gòu)化Pd-ZnO催化劑及其MSR反應性能研究
發(fā)布時間:2018-06-06 17:13
本文選題:MSR反應 + Pd。 參考:《華東師范大學》2015年碩士論文
【摘要】:質(zhì)子膜交換燃料電池(PEMFC)作為一種清潔高效的發(fā)電技術(shù),在新型汽車動力系統(tǒng)、固定發(fā)電站等方面具有廣闊的應用前景。甲醇可以通過水蒸氣重整反應在較低溫度下“釋出”氫氣,且該反應后續(xù)純化步驟少,是一個理想的便攜式燃料電池氫源反應過程。便攜式制氫系統(tǒng)的開發(fā)應兼顧催化劑與反應器的一體化設(shè)計,以解決傳統(tǒng)的固定床反應器存在的傳質(zhì)/傳熱及在便攜式應用中催化劑顆粒易破碎導致溝流等問題。本論文開展了基于薄層大面積、良好傳質(zhì)/傳熱性能的3D開放網(wǎng)絡(luò)結(jié)構(gòu)金屬纖維載持Pd-ZnO催化劑的制備及其催化甲醇水蒸氣重整制氫反應的研究。采用Cu原電池反應置換Pd再浸漬負載ZnO的方法,制備了整裝式Pd-ZnO/brass-fiber甲醇水蒸氣重整催化劑體系。結(jié)構(gòu)催化劑優(yōu)化組成為:Pd負載量2 wt%,Pd/Zn摩爾比1/3。催化劑的最佳焙燒溫度和還原溫度分別為350 ℃和450 ℃。該催化劑具有高的C02選擇性,以CH30H/H20=1/1.2(mol/mol)的混合物為原料,在WHSV=5.4h-1的條件下,當反應溫度從350 ℃升高至600 ℃C時,甲醇轉(zhuǎn)化率由60%提升至99%,同時C02選擇性始終保持在90%以上。采用Al原電池反應置換Pd再浸漬負載ZnO的方法,制備了整裝式Pd-ZnO/Al-fiber甲醇水蒸氣重整催化劑體系。結(jié)構(gòu)催化劑的最佳組成為:Pd負載量3 wt%,Pd/Zn摩爾比1/15。催化劑的最佳焙燒溫度和還原溫度分別為300 ℃和450 ℃。以CH30H]H20=1/1.2(mol/mol)的混合物為原料,在WHSV=5.4 h-1的條件下,350 ℃反應時甲醇轉(zhuǎn)化率可達.80.3%,對應的富氫尾氣中CO的體積含量僅為0.45 vol%。以整裝A1-fiber@meso-A1203為載體,采用浸漬法制備了Al-fiber@meso-A1203@3Pd-11.5ZnO催化劑,與原電池置換法制備的催化劑相比,在300 ℃焙燒和450 ℃還原后,該催化劑具有更好的低溫催化活性以及高的選擇性。在300 ℃,WHSV=2.7h-1的條件下,甲醇轉(zhuǎn)化率為96.9%,對應的富氫尾氣中CO的體積含量僅為0.45 vol%,在300 h穩(wěn)定性測試過程中,甲醇轉(zhuǎn)化率一直保持在95%以上,C02選擇性在97%左右,出口處CO濃度低于0.8 vol%。探討了ZnO和PdZn合金相互作用與反應性能的關(guān)系。
[Abstract]:Proton membrane exchange fuel cell (PEMFC), as a clean and efficient power generation technology, has a broad application prospect in new automobile power system, fixed power station and so on. Methanol can "release" hydrogen at low temperature through steam reforming reaction, and the subsequent purification steps of the reaction are few, so it is an ideal portable fuel cell hydrogen source reaction process. In order to solve the problems of mass transfer / heat transfer in traditional fixed-bed reactor and the easy breakage of catalyst particles in portable application, the integrated design of catalyst and reactor should be taken into account in the development of portable hydrogen production system. In this paper, the preparation of Pd-ZnO catalyst supported by metal fiber based on thin layer and good mass transfer / heat transfer performance and the catalytic reaction of methanol steam reforming for hydrogen production were studied. The solid Pd-ZnO / Brass-fiber methanol steam reforming catalyst system was prepared by using Cu primary cell to replace PD and impregnated ZnO. The optimum composition of the catalyst is as follows: 1 / 3 of PD / Zn molar ratio of 2 wt. The optimum calcination temperature and reduction temperature of the catalyst are 350 鈩,
本文編號:1987492
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