钯基双金属纳米材料的可控合成及其电催化性能研究

发布时间：2018-07-05 13:12

本文选题：燃料电池 + 纳米材料　；参考：《浙江师范大学》2015年硕士论文

【摘要】：随着全球环境污染的日益加重、能源的过度消耗,人类对清洁环保型能源的需求日剧上升。燃料电池由于其高效率、无噪声、无污染等特点成为重要的清洁方便的能源装置。然而,燃料电池的催化剂是燃料电池使用效率和寿命的关键。催化剂的催化性能与其粒径、结构和组成等密切相关。因此,探究高催化活性、高稳定性以及高抗毒性的金属催化剂具有重要的实际意义。本论文分别采用湿化学法和溶剂热法调控合成了五种Pd基二元贵金属纳米合金催化剂,详细研究了材料组成和结构等特性,并深入探讨了它们的相关生长机理以及电化学催化性能,主要内容如下：(1)三维多枝状Pt-Pd纳米晶体的合成及其电催化性能研究以N-甲基咪唑为结构导向剂,乙二醇为溶剂和还原剂,通过一步溶剂热法成功地制备了三维多枝状Pt-Pd合金纳米材料。该方法不需要添加任何晶种、模板或表面活性剂。所制备的多枝状Pt-Pd合金晶体与商业Pt黑和Pd黑相比具有更大的电化学活性面积,并在碱性介质中对乙二醇氧化反应表现出更好的电催化活性和稳定性。(2)枝状Pt-Pd纳米晶体的合成及其电催化性能研究采用简单的一步湿化学法,以聚乙烯基吡咯烷酮(PVP)和尿素为稳定剂和结构导向剂合成了分散性良好的枝状多孔Pt-Pd纳米晶体(Pt-Pd NDs),该方法没有使用任何晶种、模板或有毒的有机溶剂。详细研究了材料组分和结构等特性,并深入探讨了其相关生长机理。所制备的Pt-Pd NDs与商业Pt黑和Pd黑相比有较大的电化学活性面积,并在碱性介质中对甲醇和乙二醇的电氧化反应表现出高效的催化活性和稳定性。(3)花状Pt-Pd纳米晶体／还原石墨烯的合成及其电催化性能研究在亚硝酸钠和PVP的存在下,以水合肼为还原剂,通过一步湿化学法合成了花状Pt-Pd纳米晶体／还原石墨烯纳米复合材料(Pt-Pd NFs/RGOs)。所制备的Pt-Pd NFs/RGOs在酸性介质中与商业Pt-C催化剂相比对氧还原反应具有更高的催化活性和更好的稳定性。(4)单分散Pd-Cu纳米晶体／还原石墨烯的合成及其电催化性能研究在离子液晶1-十六烷基-2,3二甲基咪唑溴化物([Ci6MMIm]Br)存在下,以还原石墨烯纳米薄片(RGOs)为支撑材料,通过一步溶剂热法制备了单分散的Pd-Cu合金纳米晶体。所制得的Pd-Cu合金材料与商业Pd黑和RGOs催化剂相比具有较大的电化学活性面积,且在碱性介质中对氧还原反应表现出较高的电催化性能以及较强的抗甲醇能力。(5)单分散Au-Pd纳米颗粒／还原石墨烯的合成及其电催化性能研究在碘化钾和PVP的存在下,通过简单的一步溶剂热法,制备了单分散Au-Pd纳米颗粒／还原石墨烯复合材料。所制备的单分散Au-Pd纳米材料与商业Pd黑和RGOs催化剂相比在碱性介质中对氧还原反应表现出更强的催化能力、更好的稳定性和良好的抗醇性。
[Abstract]:With the worsening of global environmental pollution and excessive consumption of energy, the demand for clean and environment-friendly energy has increased dramatically. Fuel cell has become an important clean and convenient energy device because of its high efficiency, no noise, no pollution and so on. However, the catalyst of fuel cell is the key to the efficiency and life of fuel cell. The catalytic performance of the catalyst is closely related to its particle size, structure and composition. Therefore, it is of great practical significance to explore metal catalysts with high catalytic activity, high stability and high toxicity resistance. In this paper, five kinds of PD based binary noble metal nanocrystalline catalysts were synthesized by wet chemical method and solvothermal method respectively. The composition and structure of the catalysts were studied in detail. The related growth mechanisms and electrochemical catalytic properties of Pt-Pd nanocrystals were discussed in detail. The main contents were as follows: (1) the synthesis and electrocatalytic properties of three-dimensional multi-dendritic Pt-Pd nanocrystals were studied with N-methylimidazole as the structure guide. Three-dimensional multi-branched Pt-Pd alloy nanomaterials were successfully prepared by one-step solvothermal method using ethylene glycol as solvent and reductant. The method does not require the addition of any seed, template or surfactant. Compared with commercial Pt black and PD black, the prepared multi-branched Pt-Pd alloy crystal has a larger electrochemical active area than that of commercial Pt black and PD black. In alkaline medium, the oxidation of ethylene glycol showed better electrocatalytic activity and stability. (2) the synthesis and electrocatalytic properties of dendritic Pt-Pd nanocrystals were studied by a simple one-step wet chemical method. Poly (vinylpyrrolidone) (PVP) and urea were used as stabilizers and structural guides to synthesize dendritic porous Pt-Pd nanocrystals (Pt-Pd NDs) without any seed, template or toxic organic solvent. The composition and structure of the material were studied in detail, and the growth mechanism was discussed. Compared with commercial Pt black and PD black, the prepared Pt-Pd NDs have larger electrochemical active area. The electrooxidation of methanol and ethylene glycol in alkaline medium showed high catalytic activity and stability. (3) the synthesis and electrocatalytic properties of flower-like Pt-Pd nanocrystalline / reduced graphene were studied in the presence of sodium nitrite and PVP. The flower-like Pt-Pd nanocrystals / reduced graphene nanocomposites (Pt-Pd NFs / RGOs) were synthesized by one step wet chemical method with hydrazine hydrate as reducing agent. The prepared Pt-Pd NFS / RGOs have higher catalytic activity and better stability for oxygen reduction than commercial Pt-C catalysts in acid medium. (4) Synthesis of monodisperse Pd-Cu nanocrystals / reduced graphene and their electrocatalytic properties In the presence of ionic liquid crystal 1-hexadecyl -2- (3) dimethyl imidazolium bromide ([Ci6MMIm] Br), Monodisperse Pd-Cu alloy nanocrystals were prepared by one-step solvothermal method using reduced graphene nanocrystals (RGOs) as supporting materials. Compared with commercial PD black and RGOs catalysts, the prepared Pd-Cu alloy has a larger electrochemical active area. Moreover, the oxygen reduction reaction in alkaline medium showed high electrocatalytic activity and strong methanol resistance. (5) the synthesis and electrocatalytic properties of monodisperse Au-Pd nanoparticles / reduced graphene were studied in the presence of potassium iodide and PVP. Monodisperse Au-Pd nanoparticles / reduced graphene composites were prepared by a simple solvothermal method. Compared with commercial PD black and RGOs catalysts, the monodisperse Au-Pd nanomaterials exhibited stronger catalytic ability, better stability and better alcohol-resistance than those of commercial PD black and RGOs catalysts in alkaline medium.
【学位授予单位】：浙江师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.36;TM911.4

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