氧功能化碳复合的铂及其合金催化剂的构筑及其在甲醇燃料电池中的电催化性能研究

发布时间：2018-05-12 22:41

  本文选题：直接甲醇燃料电池 + Pt基催化剂　； 参考：《内蒙古大学》2017年硕士论文

【摘要】：近年来,随着经济的不断发展,化石能源的使用日益增长。虽然改善了我们的生活质量,但是同时也带来了严重的环境污染。目前,我国出现大面积的雾霾天气,给公民的身体健康带来了严重的威胁。因此,开发一种绿色环保的能源迫在眉睫。直接甲醇燃料电池(DMFC)作为一种新型能源利用方式,反应过程中不排放污染物,是理想的化石能源的替代品。虽然铂是目前DMFC的首选催化剂材料,但是它的催化性能低、持续性不长久以及价格高,严重阻碍了燃料电池的商业化。针对上面的问题,我们提出了一步法合成氧功能化碳复合的铂及其合金催化剂催化甲醇氧化以及氧还原,具体内容如下:1.在溶剂热条件下,通过氯化甲烷和丙三醇两相界面,成功合成了氧功能化的铂碳复合结构Pt@C-O,并且通过改变氯甲烷的种类,合成了三种不同形貌且含氧量不同的Pt@C-O催化剂。乙酰丙酮铂、苯甲酸和氯仿丙三醇两相是形成Pt@C-O结构的关键因素。进一步测试,我们发现合成的催化剂,同商用Pt/C相比,表面有很多的C-O基团和Pt-0基团。最后,通过甲醇氧化电化学性能的测试,我们发现含氧量最高的催化剂Pt@C-O具有最好的电催化稳定性以及抗一氧化碳中毒能力。2.在油浴中,二乙二醇二甲醚作为溶剂,150℃C回流,用NaBH4还原Pt(acac)2,Co(acac)2以及Ni(acac)2,合成了氧功能化碳复合PtNi@C-O二元合金以及PtNiCo@C-O三元合金。其中,利用NaCl来调控晶粒的尺寸以及溶剂碳化形成核壳结构是很新颖的合成方法。最后,通过甲醇氧化和氧还原电化学性能的测试,我们发现氧功能化碳复合的合金比20%wt.商用Pt/C具有更好的电催化性能以及抗一氧化碳中毒能力,并且三元合金的催化效率最高。3.为了进一步增加催化剂中功能化碳的含量,在油浴中,我们使用聚乙二醇为溶剂,160℃回流,用NaBH4还原Pt(acac)2,Co(acac)2以及Ni(acac)2,合成了具有更高含量的类石墨烯层状氧功能化碳负载的PtNi/C-O二元合金以及PtNiCo/C-O三元合金。通过甲醇氧化以及氧还原电化学性能的测试,我们发现氧功能化碳复合的PtNi/C-O二元合金比20 wt.%的商用Pt/C以及前面所得的所有催化剂具有更好的电催化性能。说明更高的C-O含量以及类石墨烯结构都有助于电化学性能的提高。但是当C-O含量继续升高,如PtNiCo/C-O三元合金,其在电催化过程出现强烈的产氢现象,说明甲醇氧化对C-O基团的含量具有极限值要求。
[Abstract]:In recent years, with the development of economy, the use of fossil energy is increasing day by day. Although it has improved our quality of life, it has also brought serious environmental pollution. At present, there is a large area of haze weather in China, which brings a serious threat to the health of citizens. Therefore, it is urgent to develop a green energy source. Direct methanol fuel cell (DMFC), as a new energy utilization mode, is an ideal alternative to fossil energy because it does not emit pollutants during the reaction. Although platinum is the preferred catalyst material for DMFC at present, its low catalytic performance, short duration and high price seriously hinder the commercialization of fuel cells. In order to solve the above problems, we proposed a one-step method for the synthesis of oxygen functionalized carbon composite platinum and its alloy catalysts for methanol oxidation and oxygen reduction. The specific contents are as follows: 1. Under solvothermal conditions, a platinum-carbon composite structure PtC-O with oxygen functionalization was successfully synthesized through the two-phase interface between methane chloride and glycerol. Three kinds of Pt@C-O catalysts with different morphology and different oxygen content were synthesized by changing the kinds of chloromethane. Acetylacetone platinum, benzoic acid and chloroform glycerol are the key factors for the formation of Pt@C-O structure. Further tests show that there are many C-O and Pt-0 groups on the surface of the synthesized catalyst compared with commercial Pt/C. Finally, through the electrochemical performance test of methanol oxidation, we found that the catalyst Pt@C-O with the highest oxygen content has the best electrocatalytic stability and the ability of resisting carbon monoxide poisoning. In the oil bath, diethylene glycol dimethyl ether (DME) was refluxed at 150 鈩，

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