【作者】 赵俊；

【导师】 房彩虹； 耿保友；

【作者基本信息】 安徽师范大学 ， 物理化学， 2017， 硕士

【摘要】 传统化石燃料的日益枯竭,环境污染的持续加重,迫使人们大力探索新的清洁能源。燃料电池以其高效的能量利用率,清洁的产物排放日益受到各行业的关注与青睐。然而作为燃料电池的技术关键及成本关键的铂基催化剂的催化性能仍不能胜任大规模商业化使用的需要。所以我们迫切的需要研发出具有高催化性能的铂基催化剂。本文就多孔/中空状铂基纳米催化剂的设计,可控合成及催化性能做了研究。以期能制备出具有高活性、高稳定性的铂基纳米催化剂,以降低燃料电池中铂的使用量,降低燃料电池的成本,最终达到商业化大规模使用燃料电池的目的。具体工作内容如下:1.利用温和的种子成长法合成多孔PtAg合金纳米颗粒。该铂基纳米颗粒可通过调节成长液中Ag NO3与H2Pt Cl6加入量的比值,实现纳米颗粒的形貌由多圆角花瓣状至多尖角八面体状的可控合成,同时产物纳米颗粒中的Pt/Ag原子数比从3.17(Pt76Ag24)变至1.94(Pt66Ag34)。实现了对铂基催化剂形貌及组分的同时调节。对硝基苯酚的催化还原及电催化氧化甲醇的性能测试显示Pt Ag合金纳米颗粒,尤其是多孔八面体Pt70Ag30纳米颗粒,展现出极高的催化活性及稳定性。这提示了我们可以通过同时调控Pt基纳米颗粒的形貌与组分,来提升Pt基纳米颗粒的催化性能。2.利用PdCl42-与PtCl62-还原反应速率的差异及后续空气的氧化刻蚀,制备出了多孔树突状PtPd双金属纳米颗粒,多孔空心樱花状PtPd合金纳米颗粒及多孔笼状PtPd合金纳米颗粒,并通过控制Pd前驱体投入量等因素实现了空心纳米颗粒孔经,壳层厚度以及元素组成的调节。得到的PtPd双金属纳米颗粒具有十分优异的甲醇电化学氧化催化活性,其中碳负载的多孔中空樱花状Pt32Pd68纳米颗粒具有超好的电催化稳定性,在循环测试1000次后仍能保持96.69%的电催化活性。更多还原

【Abstract】 The depletion of traditional fossil fuels and environmental pollution increasing has forced people to explore new clean energy.Fuel cell with its high energy efficiency,clean emissions are increasingly concerned and favored by various industries.However,as the key technology and the main cost of the fuel cell,Pt based catalysts’ performance is still not suitable for large-scale commercial using.Therefore,it is urgent for us to develop high catalytic performance platinum based catalysts.In this paper,the design,controllable synthesis and properties of porous/hollow platinum based catalysts were studied.In order to prepare high activity and high stability platinum based catalysts,to reduce the amount of fuel cell platinum,reduce the cost of fuel cells,and ultimately achieve the purpose of commercialization using fuel cell.Specific work as follows:1.Porous Pt Ag alloy nanoparticles were synthesized by seed growth method.By adjusting the dosage ratio of Ag NO3 and H2 Pt Cl6 in the growth solution,the morphologies of the porous alloyed nanocrystals can be tuned from multipetals to multioctahedra and the alloy composition can be varied from Pt76Ag24 to Pt66Ag34.We realized the simultaneous adjustment of the morphology and composition of Pt based catalyst.The catalytic reduction of p-nitrophenol and electrocatalytic oxidation of methanol showed that the Pt Ag alloy nanoparticles,especially the porous octahedra Pt70Ag30 nanoparticles,showed high catalytic activity and stability.It suggested us that the catalytic properties of Pt based nanoparticles can be improved by controlling the morphology and composition of Pt nanoparticles.2.We utilize the different reduction rate between Pd Cl22-and Pt Cl62-to obtain Pd core and Pd-Pt alloy shell,and then etching the Pd core by oxygen in air to synthesis Pt Pd nanodendritic,nanosakura and nanocage.By increasing the dosage of Pd precursor,hollow Pt Pd bimetallic nanoparticles’ pore size,shell thickness and elemental composition can be controlled.The Pt Pd bimetallic nanoparticles have excellent methanol oxidation catalytic activity,the carbon supported porous hollow nanosakura Pt32Pd68 has excellent electrocatalytic stability,after 1000 cycles the activity of MOR can still maintain 96.69%.更多还原