小分子调控贵金属纳米晶结构的研究
发布时间：2019-06-16 19:25
【摘要】：贵金属纳米晶因其具有优异的催化、电学和光学等性能,被广泛应用于各个领域。由于它们的性能决定于其尺寸、形貌和微观结构,因此,贵金属纳米晶的可控合成十分关键,一直是重要的研究课题。功能小分子(包括离子)与金属及反应介质之间存在配位、吸附、极化等多重相互作用,使得其具有调节金属纳米晶成核和生长的能力。因此,利用小分子调控贵金属纳米晶的形貌成为近年来的研究热点。本论文主要选择了乙腈、二恶烷、甲胺等小分子,用于调控Au、Pt及Pt-Cu合金等纳米晶的结构,评估了产物的催化性能,主要包含以下三部分:(1)利用乙腈、二恶烷和卤素离子的相互作用,有效降低了卤素离子/O2对孪晶结构的腐蚀强度,成功合成了 Au截角二十面体(孪晶)纳米晶;进一步地,将乙腈的保护作用和甲胺的选择性吸附和配位能力相结合,合成了具有高指数晶面的凹立方体Pt纳米晶,进而获得了比商业Pt/C更高的电催化甲醇氧化活性。(2)在上述实验基础上,同样利用乙腈和甲胺对金属离子、金属及反应介质之间多重相互作用,通过一锅煮的方法选择性地合成了多孔凹多面体及多孔凹八面体Pt-Cu合金纳米晶。由于其特殊的结构,这两种纳米晶对电催化甲醇氧化反应的面积比活性均高于商业Pt/C,且多孔凹八面体纳米晶的活性更高。(3)利用Cu2+,PtCl62-和PdCl42-取代传统种子生长法合成金纳米棒所加入的Ag+,并通过调节Cu2+, PtCl62-等离子的浓度研究金属离子对金纳米晶生长的影响。结果表明,和Ag+的影响不同,Cu2+等金属离子的参与可以导致类球形的Cu/Au、多面体Pt/Au等纳米颗粒的形成。
[Abstract]:Precious metal nanocrystals have been widely used in various fields because of their excellent catalytic, electrical and optical properties. Because their properties are determined by their size, morphology and microstructure, the controllable synthesis of precious metal nanocrystals is very important and has been an important research topic. There are multiple interactions between functional small molecules (including ions) and metals and reaction media, such as coordination, adsorption, polarization and so on, which makes them have the ability to regulate the nucleation and growth of metal nanocrystals. Therefore, the use of small molecules to regulate the morphology of precious metal nanocrystals has become a hot research topic in recent years. In this paper, acetonitrile, dioxane, methylamine and other small molecules were selected to regulate the structure of Au,Pt and Pt-Cu alloys, and the catalytic performance of the products was evaluated. The catalytic performance of the products included the following three parts: (1) the corrosion strength of halogen ion / O2 to twin structure was effectively reduced by using the interaction of acetonitrile, dioxane and halogen ions, and the Au cross-angled icosahedral (twin) nanocrystals were successfully synthesized. Furthermore, concave cubic Pt nanocrystals with high index crystal plane were synthesized by combining the protective effect of acetonitrile with the selective adsorption and coordination ability of methylamine, and the electrocatalytic activity of methanol oxidation was higher than that of commercial Pt/C. (2) on the basis of the above experiments, the multiple interactions between acetonitrile and methylamine on metal ions, metals and reaction media were also used. Porous concave polyhedral and porous concave octahedral Pt-Cu alloy nanocrystals were selectively synthesized by one pot cooking. Because of their special structure, the area specific activity of these two nanocrystals for electrocatalytic methanol oxidation is higher than that of commercial Pt/C, and porous concave octahedral nanocrystals. (3) Cu2, PtCl62- and PdCl42- are used to replace the Ag added to gold nanorods by traditional seed growth method, and the effect of metal ions on the growth of gold nanoparticles is studied by adjusting the concentration of Cu2 and PtCl62- plasma. The results show that, different from the influence of Ag, the participation of metal ions such as Cu2 can lead to the formation of spherical Cu/Au, polyhedral Pt/Au and other nanoparticles.
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TB383.1
本文编号：2500781
[Abstract]:Precious metal nanocrystals have been widely used in various fields because of their excellent catalytic, electrical and optical properties. Because their properties are determined by their size, morphology and microstructure, the controllable synthesis of precious metal nanocrystals is very important and has been an important research topic. There are multiple interactions between functional small molecules (including ions) and metals and reaction media, such as coordination, adsorption, polarization and so on, which makes them have the ability to regulate the nucleation and growth of metal nanocrystals. Therefore, the use of small molecules to regulate the morphology of precious metal nanocrystals has become a hot research topic in recent years. In this paper, acetonitrile, dioxane, methylamine and other small molecules were selected to regulate the structure of Au,Pt and Pt-Cu alloys, and the catalytic performance of the products was evaluated. The catalytic performance of the products included the following three parts: (1) the corrosion strength of halogen ion / O2 to twin structure was effectively reduced by using the interaction of acetonitrile, dioxane and halogen ions, and the Au cross-angled icosahedral (twin) nanocrystals were successfully synthesized. Furthermore, concave cubic Pt nanocrystals with high index crystal plane were synthesized by combining the protective effect of acetonitrile with the selective adsorption and coordination ability of methylamine, and the electrocatalytic activity of methanol oxidation was higher than that of commercial Pt/C. (2) on the basis of the above experiments, the multiple interactions between acetonitrile and methylamine on metal ions, metals and reaction media were also used. Porous concave polyhedral and porous concave octahedral Pt-Cu alloy nanocrystals were selectively synthesized by one pot cooking. Because of their special structure, the area specific activity of these two nanocrystals for electrocatalytic methanol oxidation is higher than that of commercial Pt/C, and porous concave octahedral nanocrystals. (3) Cu2, PtCl62- and PdCl42- are used to replace the Ag added to gold nanorods by traditional seed growth method, and the effect of metal ions on the growth of gold nanoparticles is studied by adjusting the concentration of Cu2 and PtCl62- plasma. The results show that, different from the influence of Ag, the participation of metal ions such as Cu2 can lead to the formation of spherical Cu/Au, polyhedral Pt/Au and other nanoparticles.
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TB383.1
【参考文献】
相关期刊论文 前1条
1 Yugang Sun;;Interfaced heterogeneous nanodimers[J];National Science Review;2015年03期
，本文编号：2500781
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