气体扩散电极在电催化苯加氢反应中的应用

利用交流阻抗复平面图判定控制步骤的方法,论证了采用SPE电极进行的水电解制氢苯电化学加氢反应是扩散控制的反应。将气体扩散电极应用于水电解制氢苯电化学加氢体系中,从而将反应由扩散控制转化为电化学步骤控制。比较了两种方法制备的气体扩散电极对反应控制步骤的改进效果。结果表明,采用镀铂碳布扩散电极可提高反应速度。     

气体扩散电极在电催化苯加氢反应中的应用

利用交流阻抗复平面图判定控制步骤的方法,论证了采用SPE电极进行的水电解制氢一苯电化学加氢反应是扩散控制的反应。将气体扩散电极应用于水电解制氢一苯电化学加氢体系中,从而将反应由扩散控制转化为电化学步骤控制。比较了两种方法制备的气体扩散电极对反应控制步骤的改进效果。结果表明,采用镀铂碳布扩散电极可提高反应速度。     

掺铂微粒的聚2,5—二甲氧基苯胺膜电极对甲醛氧化的电催化作用

以电位扫描法将铂微粒沉积在聚２，５－二甲氧基苯胺薄膜电极上制得铂微粒掺杂的聚２，５－二甲氧基苯胺电极。该电极集催化活性和电活性于一体，在甲醛浓度为１ｍｏｌ／Ｌ的硫酸溶液里的电化学氧化显示了较高的催化活性。铂微粒的大小、分布和载量，甲醛的浓度，电氧化温度等因素对电催化作用均有影响。     

电化学聚合法制备邻氨基苯酚取合物薄膜

用电化学法在铂片电极上实现了邻基苯酚在酸性溶液中的聚合，聚今氨基苯酚具有良好的电活性。用红外吸收光谱法表征了聚邻氨基酚薄膜，认为该聚合物具有梯形结构，其中吩恶嗪环作为电活性点。     

硫酸中放氧电极的分形维数和电催化性能

采用热分解法，电沉积法制备了MnO2和PbO2半导体电催化剂，测定了各电极的电化学动力学参数（a，b，io）．电极表面形貌通过扫描电镜进行了表征，同时用图形软件处理得到分形图片，依据计算机图形在计算机的存储格式，利用公式DB（F）=logNδ（F）／-logδ，用计算机语言编写程序计算了电极维数．结果表明：电极维数越大，电极的活性越高，催化性能越好．分形维数可以表征电催化剂的电催化性能．     

气体扩散电极制备条件与氧还原反应活性关系的研究

在改变催化层中聚四氟乙烯(PTFE)、造孔剂含量和热压压力等条件下制备气体扩散电极,通过计时电位法、阴极极化曲线对气体扩散电极进行测定,并将其结果用最小二乘法拟合得出电极的制备条件与氧气还原反应电化学参数之间的关系。电化学测试结果表明,各种条件下制备的电极的阴极极化过程都符合Rho提出的半经验公式规律;当气体扩散电极催化层PTFE面密度3.33mg/cm²、造孔剂(NH₄)HCO₃面密度1.05mg/cm²以及热压压力3.69MPa时,气体扩散电极的氧还原活性最佳。     

电催化苯加氢反应中气体扩散电极性能的影响因素分析

将气体扩散电极应用在电催化苯加氢反应中，通过测定电流效率，分析了气体扩散电极的制备因素对其电化学性能的影响。考察了反应温度对苯加氢反应速度和析氢反应速度的影响，推算出苯加氢反应和析氢反应的表观活化能；考察了电解液硫酸的浓度、苯蒸汽的浓度、增湿水蒸气的浓度、载气流速等对电极性能的影响，并确定最佳的外界实验操作条件。应用气体扩散电极前后的反应电流对比表明，气体扩散电极能够有效地提高反应速度。     

电化学聚合法制备邻氨基苯酚聚合物薄膜

用电化学法在铂片电极上实现了邻基苯酚在酸性溶液中的聚合。聚邻氨基苯酚具有良好的电活性。用红外吸收光谱法表征了聚邻氨基酚薄膜,认为该聚合物具有梯形结构,其中吩恶嗪环作为电活性点。     

聚吡咯膜电极对茜素红的电催化作用

用循环伏安法研究了电化学聚合的聚吡咯（ＰＰｙ）膜电极对茜素红电极反应的电催化活性。在聚吡咯膜电极上，茜素红的阳极氧化电流比在铂电极上增加数倍。相应的阴极过程也较铂电极显出一定的催化活性。茜素红在铂电极上和ＰＰｙ膜电极上都显示了吸附现象。在ＰＰｙ膜电极上用电位扫描法载入一定的铂微粒时，载铂微粒的ＰＰｙ膜电极上茜素红的电催化电流进一步增加．在较高的电位和扫描速率下更为明显；但载入的铂微粒过多时，则使电流峰变平坦。     

甲醇在铂微粒修饰的玻碳电极上的电催化氧化

利用循环伏安法等电化学方法研究了甲醇在铂微粒修饰的玻碳电极上的电催化氧化，结果表明，铂微粒修饰玻碳电极(GC—Pt)对甲醇电化学氧化呈现较高的催化活性，活化后的玻碳电极再修饰铂微粒表现更高的催化活性，其催化活性的大小与铂载量有关，同时测定了甲醇电催化氧化反应的动力学参数。     

Low temperature fabrication of high performance and transparent Pt counter electrodes for use in flexible dye-sensitized solar cells

High performance Pt counter electrode is prepared by using vacuum thermal decomposition at a relatively low (120℃) temperature on a flexible polyethylene naphthalate substrate coated with indium-doped tin oxide for use in flexible dye-sensitized solar cells.The obtained Pt counter electrode shows a good chemical stability,high light transmittance,and high electrocatalytic activity for the I3-/I-redox reaction.The energy conversion efficiency of a flexible dye-sensitized solar cell based on the prepared Pt counter electrode and a TiO 2 /Ti photoanode reaches 5.14% under a simulated solar light irradiation with intensity of 100 mW cm-2.     

直接氧化型葡萄糖燃料电池的研制

研究了新型Ｐｔ／Ｃｏ／Ｃ电催化剂的制备,并以其作为阳极制备直接氧化型葡萄糖燃料电池．实验结果证明,葡萄糖燃料电池具有较高的电动势和较优的电极性能,电极稳定性好,不存在毒化问题,是一种有开发前景的燃料电池．     

碳载铂电极在甲酸氧化中的电催化特性

通过对碳载铂电极在甲酸氧化中电催化特性的研究,证明在玻碳表面镀铂黑制备高活性、低成本、新型实用型电催化剂的方法是成功的．研究结果表明,甲酸在碳载铂电极上电催化氧化是按双途径机理进行的．     

脉冲电沉积法制备直接甲醇燃料电池电极研究

以聚四氟乙烯(PTFE)化碳纸为基板,以Nafion 炭黑 Pt(Ru)金属盐为预沉积层,用脉冲电沉积法制备不同组分的PtRu合金直接甲醇燃料电池(DMFCs)电极。实验考察了不同脉冲电沉积沉积时间与间歇时间比例(ton/toff)、Pt与Ru质量比、Nafion载量、催化剂载量与碳黑比例等因素对电极电催化氧化甲醇性能的影响。以循环伏安法(CV)表征电极活性,X射线衍射(XRD)表征催化剂晶体结构及粒子大小。最佳沉积条件:ton/toff为100 ms/300 ms;n(Pt)/n(Ru)为1;m(PtRu)/m(C)为0.4;m(C)/m(Nafion)为6。制得有效面积133 m2/g、粒径2.1 nm的催化剂。     

Photo-improved hydrogen evolution reaction activity of the Pt/CdS electrocatalyst

The effect of CdS content on the photo-induced improvement of hydrogen evolution reaction activity of the Pt/CdS electrocatalyst was investigated. Although the electrons transferred from CdS to Pt in the Pt/CdS electrocatalyst increased with the CdS content under illumination, the electrochemical active surface area of the Pt/CdS electrocatalyst decreased with the CdS content, resulting that the photo-induced improvement of hydrogen evolution reaction activity of the Pt/CdS electrocatalyst decreased with the CdS content.     

A Mathematic Model of Gas-diffusion Electrodes in Contact with Liquid Electrolytes

A mathematic model is developed which is applied to analyze the main factors that affect electrode performance and to account for the process of reaction and mass transfer in gas-diffusion electrodes in contact with liquid electrolytes. Electrochemical Thiele modulus φ^2 and electrochemical effectiveness factor η are introduced to elucidate the effects of diffusion on electrochemical reaction and utilization of the gas-diffusion electrode. Profile of the reactant along axial direction is discussed, dependence of electrode potential V on current density J, are predicated by means of the newly developed mathematical model.     

典型航空电缆的热解动力学研究

含氟聚合物绝缘电缆为航空线缆的主要体系. 选取以聚四氟乙烯(PTFE)、可熔性聚四氟乙烯(PFA)、聚全氟乙丙烯(FEP)3种含氟聚合物为护套的航空电缆作为研究对象,采用热重-差热同步分析仪研究氮气气氛中不同升温速率下3种材料的热分解特性,结果表明:PTFE的热分解过程为1个阶段,而PFA和FEP的热分解过程均为2个阶段,且PTFE的初始分解温度和10%质量损失率温度均高于PFA和FEP的相应值,因此,PTFE比PFA和FEP更不容易发生热解. 分别使用Ozawa法、Kissinger-Akahira-Sunose(KAS)法、Starink法和Friedman法进行非等温的热解动力学分析,针对同一材料,Ozawa法、KAS法以及Starink法计算出的表观活化能基本相同,而Friedman法计算出的表观活化能略高于上述3种方法所得结果. 对比可知PTFE的初期表观活化能和平均表观活化能均大于PFA和FEP的相应值,因此PTFE在整个热解反应过程中的热稳定性相对最优.     

Highly stable N-containing polymer-based Fe/Nx/C electrocatalyst for alkaline anion exchange membrane fuel cell applications

A cost-effective electrocatalyst with high activity and stability was developed. The Fe-Nx and pyridinic-N active sites were embedded in nitrogen-doped mesoporous carbon nanomaterial by carbonization at high temperature. The electrocatalyst exhibited excellent electrochemical performance for the oxygen reduction reaction, with high onset potential and half-wave potential values (E_onset = 1.10 ?V and E_1/2 ?= ?0.944 ?V) than 20 ?wt % Pt/C catalyst (1.04 and 0.910 ?V). The mass activity of the Schiff base network (SNW) based SNW-Fe/N/C@800° electrocatalyst (0.64 ?mA ?mg^?1 @ 1 ?V) reached about half of the commercial Pt/C electrocatalyst (1.35 ?mA ?mg^?1 @ 1 ?V). The electrocatalyst followed the 4-electron transfer mechanism due to very low hydrogen peroxide yield (H₂O₂ ?< ?1.5%) was obtained. In addition, this electrocatalyst with dual active sites showed high stability during cyclic voltammetry and chronoamperometry measurements. More importantly, the electrocatalyst also demonstrated the power density of 266 ?mW ?cm^?2 in the alkaline anions exchange membrane fuel cell (AEMFC) test, indicating its prospective application for fuel cells.     

Influence of substrate metals on the crystal growth of AlN films

AlN films were deposited by reactive radio frequency (RF) sputtering on various bottom electrodes, such as Al, Ti, Mo, Au/Ti, and Pt/Ti. The effects of substrate metals on the orientation of AlN thin films were investigated. The results of X-ray diffraction, atomic force microscopy, and field emission scanning electron microscopy show that the orientation of AlN films depends on the kinds of substrate metals evidently. The differences of AlN films deposited on various metal electrodes are attributed to the differences in lattice mismatch and thermal expansion coefficient between the AlN material and substrate metals. The AlN film deposited on the Pt/Ti electrode reveals highly the c-axis orientation with well-textured columnar structure. The positive role of the Pt/Ti electrode in achieving the high-quality AlN films and high-performance film bulk acoustic resonator (FBAR) may be attributed to the smaller lattice mismatch as well as the similarity of thermal expansion coefficient between the deposited AlN material and the Pt/Ti electrode substrate.     

Sm掺杂Ti/SnO2-Sb电极电催化氧化性能

采用涂层热解法制备Sm掺杂Ti/SnO2-Sb电极.以C6H5NO3(对硝基苯酚)为目标有机物,考察不同热处理温度、不同Sm掺杂量下制备的电极的电催化性能,采用LSV(线性扫描曲线)、降解曲线和破损的分析方法研究电极的电催化氧化性能和使用寿命.结果表明:最佳热处理温度为550℃,xSn∶xSb∶xSm=100∶10∶1电极的综合性能最好.在降解有机物试验中,不掺杂Sm的电极降解率为74.4%,掺杂率为1%的电极降解率为85.6%,掺杂率为2%的电极的降解效率仅为74.2%.因此,适量的稀土Sm掺杂有利于提高电极的电催化性能.