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1.
载铂微粒的聚苯胺薄膜电极对甲醇的电催化氧化 总被引:9,自引:1,他引:9
用电化学方法制备的载有金属铂微粒的聚苯胺(PAn)膜电极对甲醇在硫酸中的电化学氧化具有很高的催化活性。电极材料中的铂微粒是沿着聚苯胺的纤维分布的,而且主要沉积在PAn膜的表面。 相似文献
2.
QiuHongLI LinNIU ChangQiaoZHANG FengHuaWEI HuZHANG 《中国化学快报》2004,15(1):115-117
The oxidation of methanol was investigated on platinum-modified polyaniline electrode.Changes in the electrode rotation rates (Ω) during platinum electrodeposition remarkably affect the formation and distribution of platinum in the polymer matrix and consequently lead to different currents of methanol oxidation. The results show that platinum loading is proportional to rotation rates Ω^1/2. 相似文献
3.
铂微粒修饰的聚苯胺薄膜电极对甲醛氧化的电催化作用 总被引:6,自引:2,他引:6
以电位扫描法把铂微粒沉积在聚苯胺(PAn)薄膜是上以制得铂微粒修饰的聚苯胺薄膜电极。该电极的催化活性以甲醛在0.5mol/L硫酸溶液中的电化学氧化测定。它集催化活性和电活性于一体,对甲醛在酸性介质中的电化学氧化显示了非常高的电催化活性。较之裸铂电极,PAn薄膜电极,其催化电流提高10倍。铂微粒的大小,分布和载量,甲醛的浓度,基体金属的种类等因素对电极材料的催化活性均有影响。 相似文献
4.
Jakub Haberko Joanna Raczkowska Andrzej Bernasik Wojciech Łużny Jakub Rysz Andrzej Budkowski 《Macromolecular Symposia》2008,263(1):47-52
Summary: In the present work knowledge the authors tried to direct the phase separation process in a thin polymer composite film to manufacture a polymer pattern via self organisation of the blend components. The Au substrate was modified by applying with a PDMS stamp a pattern of alternating stripes of a self-assembled monolayer. This in turn influenced the microstructure of the blend, allowing for the production of elongated domains repeating the pattern of the substrate. The blends studied in this work contained conducting polyaniline doped with camphorsulfonic acid or diphenyl phosphate and polystyrene. The role of the dopant was to induce electrical conductivity in polyaniline as well as to improve its solubility in common organic solvents. The microstructure of thin films was analysed using atomic force microscopy (AFM), dynamic secondary ion mass spectroscopy (dSIMS) and optical microscopy. 相似文献
5.
The composite electrode of platinum‐modified polyaniline film is formed in 0.5 M H2SO4 + 3 mM H2PtCl6 solution by cyclic potential or constant potential deposition of platinum particles in polyaniline film. To make a comparison, the polyaniline film with the same initial thickness and structure is also treated with the cyclic potential or constant potential polarization in 0.5 M H2SO4 solution. The electrochemical impedance spectroscopy (EIS) of the composite electrode of platinum‐modified polyaniline film is studied in sulfuric acid solution and compared with the EIS of the polyaniline film without platinum dispersion. The results show that the different modes of potential polarization affect greatly the nature and distribution of the platinum particles, instead of the structure of the polyaniline film (matrix). The electrode reaction kinetics and mass transport process parameters involving charge transfer resistance (Rct), double layer capacitance (Cdl), constant phase elements (CPE) and Warburg impedance in platinum substrate/platinum‐modified polyaniline film/solution interface are discussed on the basis of the interpretation of the characteristic impedance spectra and connected to the electrocatalytic activity on the oxidation of methanol molecules. 相似文献
6.
以氨基化的碳纳米管为基体,通过界面聚合方法将聚苯胺共价接枝于碳纳米管表面,负载催化剂颗粒Pt. 通过透射电镜(TEM)、X射线衍射(XRD)及电化学方法对催化剂进行了表征. TEM结果表明通过界面聚合的方法可以使聚苯胺均匀地接枝于碳纳米管表面. 电化学测试结果表明,碳纳米管共价接枝聚苯胺作为载体可以提高催化剂的抗CO中毒性能,有利于对甲醇的催化氧化. 研究其对甲醇的催化活性,并与商业的JM(Pt/C)催化剂进行了对比. 结果表明,碳纳米管共价接枝聚苯胺,有效提高了催化剂的稳定性,延长催化剂的寿命. 相似文献
7.
8.
在加有苯胺的亚相上,铺展硬脂酸分子,在气液界面上可形成苯胺-硬脂酸Langmuir膜.随膜压增大至5.0×10 ̄(-6)N时,苯胺与硬脂酸间的氢键会发生重排,形成另外一种构型的Langmuir膜,分子所占面积减小,膜增加一个苯环的厚度.将膜转移到SnO_2导电玻璃基底上,制成硬脂酸-苯胺Langmuir-Blogdett膜,经电化学氧化,苯胺可聚合成薄膜。膜夹在两层硬脂酸分子间,它的电化学行为不仅受到离子膜中传输过程的影响,同时受到硬脂酸极性亲水端(-COO ̄-)的作用. 相似文献
9.
硬脂酸镍L—B膜对甲醇的电催化氧化 总被引:1,自引:0,他引:1
硬脂酸镍L-B膜电极对甲醇具有良好的电催化作用,膜中镍离子主要以-CooNi(OH)形式存在,电催化过程受OH-浓度的影响,也涉及甲醇分子在膜内的穿透。 相似文献
10.
V. S. Gurin V. B. Prokopenko A. A. Alexeenko D. L. Kovalenko I. M. Melnichenko 《Journal of inclusion phenomena and macrocyclic chemistry》1999,35(1-2):291-297
A novel method of fabrication of silica-based sol-gel films and glasses containing small semiconductor particles was developed. A series of films and glasses with nanoparticles of copper chalcogenides (CuS, Cu2Se, CuInS2) and metal particles (Cu) were fabricated through the chemical transformation of precursors incorporated into a sol-gel derived matrix. The properties of the nanoparticles studied by means of XRD, XPS, TEM and optical spectroscopy are provided both by size effects and the chemical nature of surface states and can be controlled at different steps of chemical treatment. 相似文献
11.
利用层层自组装(LBL)结合原位光照还原法,制备了一系列{还原氧化石墨烯/多金属氧酸盐}n多层复合膜({rGO/POMs}_n),并以此作为载体,再通过恒电势法将Pt纳米粒子电沉积到复合膜载体上,得到一种P t/{rGO/SiW_(12)}_n燃料电池阳极纳米复合膜催化剂。用紫外可见分光光度计(UV-Vis)、原子力显微镜(AFM)以及扫描电子显微镜(SEM)等技术手段对载体复合多层膜的生长情况以及负载Pt纳米簇的表面形貌进行表征。结果表明,载体多层膜{rGO/SiW_(12)}_6被连续均匀地组装到了不同基底(氧化铟锡,ITO或玻碳,GC)表面且多层膜表面平整,在选定恒电势下,沉积于其表面的Pt纳米粒子具有花簇状形貌且分布均匀。比较研究了分别引入3种不同的多金属氧酸盐(硅钨酸盐SiW_(12),磷钼酸盐PMo_(12),磷钨酸盐PW_(12))制得的多层复合膜催化剂,即Pt/{rGO/SiW_(12)}_6、Pt/{rGO/PMo_(12)}_6和Pt/{rGO/PW_(12)}_6。电化学实验研究表明,在甲醇酸性溶液中,Pt/{rGO/SiW_(12)}_6复合膜相较于Pt/{rGO/PMo_(12)}_6、Pt/{rGO/PW_(12)}_6和Pt作为催化剂对甲醇氧化具有更好的电催化活性、电化学稳定性以及更优异的抗CO毒化性能,是一种颇有应用前景的燃料电池阳极催化剂。 相似文献
12.
Yablokov M. Yu. Ivanov V. F. Cheberyako K. V. Gribkova O. L. Nekrasov A. A. Vannikov A. V. Tomilin M. G. 《Russian Journal of Electrochemistry》2004,40(3):349-351
By using formal estimation methods, it is shown that heterogeneous redox structures, which are formed in the course of oxidation of vacuum evaporated thin polyaniline layers in the temperature range of 0–30°C, become more ordered with the increase in the oxidation temperature. 相似文献
13.
Pt微粒修饰纳米纤维聚苯胺电极对甲醇氧化电催化 总被引:9,自引:0,他引:9
以脉冲电流法制备的纳米纤维状聚苯胺(PANI)为Pt催化剂载体,用它制备了甲醇阳极氧化的催化电极Pt/(nano-fibular PANI).研究结果表明, Pt/(nano-fibular PANI)电极对甲醇氧化具有很好的电催化活性,并有协同催化作用.在相同的Pt载量条件下, Pt/(nano-fibular PANI)电极比Pt微粒修饰的颗粒状聚苯胺电极Pt/(granular PANI)具有更好的电催化活性.此外, Pt的电沉积修饰方法同样影响Pt/(nano-fibular PANI)电极对甲醇氧化的催化活性.脉冲电流法沉积Pt形成的复合电极较循环伏安法电沉积得到的Pt复合电极具有更优异的催化活性. 相似文献
15.
聚苯胺对抗坏血酸的电催化氧化及磁效应 总被引:2,自引:0,他引:2
磁场对生物体系及其中物理现象和化学反应的影响历来是人们关注的焦点[1].磁场能影响分子、细胞、组织、器官乃至整个生物体系的新陈代谢功能.磁场对化学反应的影响通常是通过对自由基(对)施加作用而体现的,磁场改变了未成对电子的自旋方式,从而改变了反应的墙,进而改变化学反应的速率[2].此外,磁场对电化学体系的影响也有报导[3],外加磁场激发溶液流动,产生磁流体动力学效应(MHD)[4],增大传质速度,影响电化学进程.本文研究聚苯胺(PAN)修饰电极上抗坏血酸(AA)的电催化氧化,并讨论了膜厚、溶液pH值、AA浓度(CAA… 相似文献
16.
The most prominent and intensively studied anode catalyst material for direct methanol oxidation fuel cells consists of a combination of platinum (Pt) and ruthenium (Ru). Classically, their high performance is attributed to a bifunctional reaction mechanism where Ru sites provide oxygen species at lower overpotential than Pt. In turn, they oxidize the adsorbed carbonaceous reaction intermediates at lower overpotential; among these, the Pt site-blocking carbon monoxide. We demonstrate that well-defined Pt modified Ru(0001) single crystal electrodes, with varying Pt contents and different local PtRu configurations at the surface, are unexpectedly inactive for the methanol oxidation reaction. This observation stands in contradiction with theoretical predictions and the concept of bifunctional catalysis for this reaction. Instead, we suggest that pure Pt defect sites play a more critical role than bifunctional defect sites on the electrodes investigated in this work. 相似文献
17.
以草酰胺作为保护剂,采用胶体法合成铂纳米晶,考察了不同溶液pH值、前驱体与保护剂反应物配比对铂纳米晶形貌及其甲醇电催化氧化活性的影响. 测试表明,pH = 5、反应物配比1:20合成的铂纳米晶的甲醇电催化氧化活性最佳,其峰电流密度达到1709 μA·cm-2. 空气中搁置3个月后,其表面形貌变化不大,但甲醇的电催化活性显著降低. 0.05 ~ 1.2 V电位范围循环扫描100周期,其循环伏安曲线明显变化,晶体表面原子排列方式也发生变化,由易毒化(100)面逐渐转化为(110)面,其甲醇电催化活性增加. 相似文献
18.
Dr. Xiaofei Yu Dr. Lanlan Li Yanqiu Su Dr. Wei Jia Lili Dong Prof. Dr. Dingsheng Wang Prof. Dr. Jianling Zhao Prof. Dr. Yadong Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4960-4965
Platinum–copper nanoframes were produced from copper nanoparticles by a one‐pot synthesis method. The growth mechanism was thoroughly studied by experiment and theoretical calculations. Owing to the unique structure, Pt‐Cu nanoframes exhibited significantly enhanced catalytic activity toward the electro‐oxidation of methanol compared to commercial Pt black. 相似文献
19.
聚苯胺衍生物膜修饰电极的电化学和催化性质 总被引:4,自引:0,他引:4
采用聚 2,5 二甲氧基苯胺(PDMAn)、聚邻甲苯胺(POT)膜修饰电极,以异丙醇(i P)氧化为模型反应,研究功能性膜电极的电催化性能.两种聚合物的伏安行为都表现为两对氧化还原峰;与镀铂的Pt电极比较,Pt金属化的PDMAn和POT修饰电极,大大提高了i P氧化电流密度,而且随着循环次数增加,氧化电流不断增大,表明功能性膜修饰电极具有较高的催化活性. POT修饰电极在较低的铂含量下就表现出对i P的强烈催化活性,而且对低浓度i P的氧化,具有较高的响应灵敏度;此外POT还具有良好的环境稳定性,可望成为一种具有实际应用前景的电化学传感器. 相似文献