整装金属纤维结构化Pd-ZnO催化剂及其MSR反应性能研究

发布时间：2018-06-06 17:13

  本文选题：MSR反应 + Pd　； 参考：《华东师范大学》2015年硕士论文

【摘要】：质子膜交换燃料电池(PEMFC)作为一种清洁高效的发电技术,在新型汽车动力系统、固定发电站等方面具有广阔的应用前景。甲醇可以通过水蒸气重整反应在较低温度下“释出”氢气,且该反应后续纯化步骤少,是一个理想的便携式燃料电池氢源反应过程。便携式制氢系统的开发应兼顾催化剂与反应器的一体化设计,以解决传统的固定床反应器存在的传质／传热及在便携式应用中催化剂颗粒易破碎导致沟流等问题。本论文开展了基于薄层大面积、良好传质／传热性能的3D开放网络结构金属纤维载持Pd-ZnO催化剂的制备及其催化甲醇水蒸气重整制氢反应的研究。采用Cu原电池反应置换Pd再浸渍负载ZnO的方法,制备了整装式Pd-ZnO/brass-fiber甲醇水蒸气重整催化剂体系。结构催化剂优化组成为：Pd负载量2 wt%,Pd/Zn摩尔比1/3。催化剂的最佳焙烧温度和还原温度分别为350 ℃和450 ℃。该催化剂具有高的C02选择性,以CH30H/H20=1/1.2(mol/mol)的混合物为原料,在WHSV=5.4h-1的条件下,当反应温度从350 ℃升高至600 ℃C时,甲醇转化率由60%提升至99%,同时C02选择性始终保持在90%以上。采用Al原电池反应置换Pd再浸渍负载ZnO的方法,制备了整装式Pd-ZnO/Al-fiber甲醇水蒸气重整催化剂体系。结构催化剂的最佳组成为：Pd负载量3 wt%,Pd/Zn摩尔比1/15。催化剂的最佳焙烧温度和还原温度分别为300 ℃和450 ℃。以CH30H]H20=1/1.2(mol/mol)的混合物为原料,在WHSV=5.4 h-1的条件下,350 ℃反应时甲醇转化率可达.80.3%,对应的富氢尾气中CO的体积含量仅为0.45 vol%。以整装A1-fiber@meso-A1203为载体,采用浸渍法制备了Al-fiber@meso-A1203@3Pd-11.5ZnO催化剂,与原电池置换法制备的催化剂相比,在300 ℃焙烧和450 ℃还原后,该催化剂具有更好的低温催化活性以及高的选择性。在300 ℃,WHSV=2.7h-1的条件下,甲醇转化率为96.9%,对应的富氢尾气中CO的体积含量仅为0.45 vol%,在300 h稳定性测试过程中,甲醇转化率一直保持在95%以上,C02选择性在97%左右,出口处CO浓度低于0.8 vol%。探讨了ZnO和PdZn合金相互作用与反应性能的关系。
[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，

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