【作者】 王燕；

【导师】 侯莉；

【作者基本信息】 燕山大学 ， 应用化学， 2017， 硕士

【摘要】 随着纳米结构的提出,纳米材料受到越来越多的关注,其中一维纳米结构因其独特的各向异性、较少的缺陷位点、良好的传质导电性等优点受到追捧。因此人们尝试制备一维Pt纳米线应用于燃料电池。贵金属Pt的储量有限且价格昂贵,虽然改变Pt的形貌在一定程度上可以提高其催化性能,但远远达不到商业化的应用。尝试在改变形貌的同时通过添加非贵金属来降低Pt的消耗,同时提高催化剂的电催化性能成为燃料电池研究领域的一种方法。本论文选用中空螺旋结构的胰岛素纤维为模板,通过添加过渡金属实现了具有超细超长一维结构的铂基双金属纳米线的制备。采用透射电子显微镜（TEM）、X射线衍射（XRD）、电感耦合等离子体发射光谱（ICP-OES）、X射线光电子谱（XPS）对样品的结构、形态及组成进行了表征,采用电化学催化实验考察了样品的催化性能。具体的研究内容及结果如下:使用中空螺旋结构的胰岛素纤维为模板,PtCl₄与Fe（NO）₃混和盐溶液共还原制备了一维Pt-Fe纳米线,纳米线尺寸均一,直径约为1.8 nm,长达数微米。考察了PtCl₄与Fe（NO）₃混和盐溶液反应物浓度、摩尔量以及还原剂种类等因素对产物形貌的影响。催化氧化甲醇的测试结果表明一维Pt-Fe纳米线催化甲醇反应的电流密度达到0.753 mA·cm^-2,相比于市售Pt/C的0.519 mA·cm^-2,提高了45.09%;循环500圈后一维Pt-Fe纳米线电流密度仅下降了15%,相对于市售Pt/C其稳定性明显提高。分别以PtCl₄与Ni（NO）₂的混合盐溶液以及Pt Cl₄与CoCl2混合盐溶液为前驱体制备得到超细一维Pt-Ni、Pt-Co纳米线。考察了混和盐溶液反应物浓度、摩尔量以及还原剂种类等因素对产物形貌的影响。催化甲醇氧化测试表明,一维Pt-Ni、Pt-Co纳米线的电化学面积比活性分别为0.663 mA·cm^-2和5.664 mA·cm^-2,均明显高于市售Pt/C(0.519 mA·cm^-2),且其中Pt-Co催化剂的性能最好,催化活性是市售Pt/C的10倍之多。同时,一维Pt-Co纳米线在乙醇催化反应中也表现出更好的催化性能。更多还原

【Abstract】 The nano materials have attracted more and more attention along with the development of nano structure,especially for the one dimensional nanostructure,because of its unique anisotropy,less defect sites and good mass transfer conductivity.Some one dimensional Pt nanowires have been prepared to use in fuel cells.Since the precious metal Pt is limited and expensive.to some extent,changing the shape of Pt can improve its catalytic properties,but far less than the commercial applications.Trying to change the morphology and reduce the consumption of Pt by adding non-noble metal to improve the electrical catalytic performance of catalyst has become an effective method in fuel cells research field.In this paper,the ultrathin and superlong one dimensional Pt-based binary-metal nanowires were prepared by using the hollow and spral insulin fibers as templates and adding some other transition metals.Transmission electron microscope（TEM）,X-ray diffraction（XRD）,inductively coupled plasma emission spectroscopy（ICP-OES）,X-ray photoelectron spectroscopy（XPS）have been used to characterize the samples`s structure,morphology and composition.Electrochemical catalysis experiments were carried out to investigate the catalytic properties of the samples.The main work and results are as follows:The one-dimensional Pt-Fe nanowires with uniform diameter of about 1.8 nm and length of several microns were prepared by using the hollow and spiral insulin fiber as the template and reduction of PtCl₄ and Fe（NO）₃ mixed salt solution.The influences of concentrations and molecular weight of PtCl₄ and Fe（NO）₃ and species of reductants on the morphology of the products were studied.Catalytic oxidation of methanol test results show that the current density of the one-dimensional Pt-Fe nanowires is 0.753 mA·cm^-2,which is 45.09% higher than that of the commercial Pt/C(0.519 mA·cm^-2).The current density of one dimensional Pt-Fe nanowires fell by only 15% after 500 cycles,indicating that the stability of Pt-Fe nanowires has improved significantly compared with the commercial Pt/C.The ultrathin one-dimensional Pt-Ni and Pt-Co nanowires were prepared by reduction of PtCl₄ and Ni（NO）₂ mixed salt solution and PtCl₄ and CoCl2 mixed precursors,respectively.The factors such as solution concentration and molecular weight of reactants,and reductant species were changed to investigate their influences on the morphology of the product.Catalytic methanol oxidation tests results show that the activity of one dimensional Pt-Ni and Pt-Co nanowires are 0.663 mA·cm^-2 and 5.664 mA·cm^-2,respectively,which are significantly higher than that of commercial Pt/C(0.519 mA·cm^-2).The performance of Pt-Co catalyst is the best,up to 10 times as much as that of commercially available.Meanwhile,the one-dimensional Pt-Co nanowires present higher catalytic performance in ethanol catalytic reaction.更多还原