钛基材料用作DMFC阳极催化剂的载体

从催化效率、选择性和稳定性等方面综述了钛基材料对DMFC中催化剂电催化氧化甲醇效果的影响,讨论并分析了钛基材料作为DMFC阳极催化剂载体在提高甲醇电催化方面的机理,对钛基材料作为DMFC阳极催化剂载体的应用前景和使用价值进行了展望.     

不同还原法制备的Pt-Co/C催化剂电催化还原性能

为寻求一种较好的Pt-Co/C纳米合金催化剂合成方法,运用浸渍还原法制备两种Pt-Co/C催化剂,运用循环伏安和线性扫描的方法测试它们在H₂SO₄溶液中有无CH₃OH时,对O₂的电催化还原情况及抗甲醇性能,同时与商用Pt/C催化剂进行还原性能比较。结果表明：与商用Pt/C催化剂电极相比,Pt-Co/C (1)催化剂电极对O₂的电催化还原效果较好。80℃时制备的Pt∶Co＝3∶1的Pt-Co/C催化剂电极对O₂的电催化还原效果最佳。扫描电子显微镜(Scanning Electron Microscope,SEM)和透射电子显微镜(Transmission Electron Microscope,TEM)观察表明,Pt-Co/C (1)催化剂粒径小且分散均匀。采用浸渍还原法,以硼氢化钠为还原剂制得的Pt-Co/C (1)催化剂对O₂的电催化还原性能较好,同时具有较好的抗甲醇氧化能力。     

直接甲醇燃料电池中碳载Pt—TiO2阳极复合催化剂的研究

首次报道了通过化学还原和溶胶－凝胶法了直接甲醇燃料电池（DMFC）中Pt-TiO2/C阳极复合催化剂对甲醇氧化呈出了很好的电催化活性和稳定性,研究了催化剂的组份和制备条件对催化剂性能的影响,这种催化剂有望能在DMFC实际使用。     

直接甲醇燃料电池中碳载Pt-TiO2阳极复合催化剂的研究

首次报道了通过化学还原和溶胶?凝胶法制备了直接甲醇燃料电池（DMFC）中Pt-TiO2/C阳极复合催化剂对甲醇氧化呈现出了很好的电催化活性和稳定性.研究了催化剂的组份和制备条件对催化剂性能的影响.这种催化剂有望能在DMFC实际使用.     

PtPb/HCSs催化剂制备及电催化氧化甲醇研究

以二氧化硅微球作模板,葡萄糖为碳源,通过水热法成功合成粒径均一、尺寸较小的碳空心球(HCSs),并以此为载体合成碳空心球载铂铅纳米微粒复合催化剂(PtPb/HCSs),在1 mol.L-1CH3OH+0.5mol.L-1H2SO4混合溶液中考察了PtPb/HCSs催化剂对甲醇的电催化氧化性能。样品的成份、结构和形貌分别用SEM、TEM、XRD和EDS进行表征。循环伏安(CV)及计时电流法实验表明碳空心球载铂铅催化剂对于甲醇氧化具有良好的电催化活性及稳定性。PtPb/HCSs电极优异的催化性能归因于碳空心球的高比表面积以及Pb的协同作用,是一种优良的直接甲醇燃料电池(DMFC)阳极材料。     

碳基材料在电催化还原CO2中的应用

电催化还原CO₂能够将CO₂转换成高附加值的化学品或燃料,该工艺是一种缓解能源危机和全球变暖的理想途径。但由于缺乏性能优异、价格低廉、环境友好的催化剂,该途径的实用化仍具挑战性。碳基催化剂因具有资源丰富、导电性好、比表面积大、环境友好等优点而被广泛应用于多种催化反应中。目前报道的系列碳基催化剂在CO₂还原反应中也展现出极好的催化性能和应用潜力。综述了N原子掺杂、构造缺陷、单原子负载和金属纳米颗粒负载等手段对碳基材料电催化还原CO₂性能的影响及其催化机制,并总结了电催化还原CO₂所面临的挑战。同时对未来碳基电催化剂的合成及发展进行了展望。     

原子配比对PtMoNi/C催化剂性能的影响

采用浸渍还原法制备了PtMoNi/C(w=20%)直接甲醇燃料电池阳极催化剂;研究了不同原子配比对催化剂性能的影响;通过XRD催化剂的晶体结构进行了分析;用循环伏安曲线和阶跃电位曲线研究催化剂对CH3OH的电催化氧化.结果表明:当Pt:Mo:Ni为6:2:2时催化剂的催化氧化甲醇的性能最佳.     

Ce掺杂的NiCo2O4催化氧化甲苯性能研究

NiCo₂O₄是一种很前景的甲苯氧化催化剂。本文以Ce为杂原子,利用水热法制备Ce/NiCo₂O₄催化剂,以提高NiCo₂O₄尖晶石表面活性氧生成速率。采用氢气程序升温还原(H₂-TPR)、X射线光电子能谱(XPS)、X射线衍射(XRD)、比表面积测定(BET)、以及透射电子显微镜(TEM)等表征催化剂。通过改变铈掺杂量,得到最佳掺杂比例。甲苯降解实验表明,在甲苯浓度为2538ppm,空速为10000h^_-1,催化剂体积为0.5mL 时,一次水热法制备得到的15%Ce/NiCo₂O₄催化剂降解性能最优(T₉₉=267℃),在267℃下进行催化反应72h后催化剂性能无显著变化。机理研究发现,掺杂铈可提升催化剂中高价金属含量,同时催化剂良好的氧化还原性能可加快表面活性氧生成速率,从而催化性能得以提升。     

碳载Pt-TiO2阳极催化剂对甲醇氧化的电催化活性和稳定性

近年来,直接甲醇燃料电池（DMFC）由于使用液体燃料而越来越受到重视,但目前DMFC存在的一个普遍的问题是常用的Pt阳极催化剂易被甲醇氧化的中间产物所毒化.因此,一些研究者研究了能抗甲醇氧化的中间产物毒化的Pt二元合金或Pt和过渡金属氧化物复合催化剂,如Pt-Ru[1]、Pt-Sn[2]、Pt-WOx[3]等.考虑至TiO2在酸性溶液中的稳定性,Hamnett研究组[4]和我们研究组[5]发现pt-TiO2/Ti复合电极对甲醇氧化有很好的电催化活性和抗中毒的能力.本文报道了制备能在DMFC中实际使用的碳载Pt-TiO2催化剂（Pt-TiO2/C）的方法和比较了Pt-TiO2/C和Pt/C电极对甲醇氧化的电催化活性和稳定性.用固相法制备含Pt20％的Pt/C催化剂[6],将制得的pt/C催化剂和Ti（OBu）4按摩尔比1:1的比例悬浮在乙醇中,超声波震荡并加水,使Ti（OBu）4完全水解成TiO2,并均匀沉积到Pt/C催化剂上,洗涤,真空干燥,500℃热处理     

直接甲醇燃料电池用Co-N-C电催化剂的制备及性能

以三聚氰胺甲醛树脂和硝酸钴为前驱体,在Ar保护下采用高温碳化方法制备用于直接甲醇燃料电池(DMFC)阴极的含氮碳载钴(Co-N-C)氧还原电催化剂.利用热重与红外光谱联用、X射线衍射分析、元素分析等方法表征了催化剂的制备过程和结构,采用旋转圆盘电极测试考察了不同碳化温度对Co-N-C电催化剂氧还原催化活性的影响及电催化剂的耐醇性能,并采用该催化剂为阴极催化剂进行DMFC单电池测试.结果表明:Co-N-C电催化剂具有较高的电催化活性和较好的耐醇性能;其氧还原起始电位在0.5V(vs.SCE)左右;700℃碳化温度下制备的Co-N-C电催化剂具有最高的氧还原催化活性.     

阳极电催化剂在直接甲醇燃料电池中的应用

直接甲醇燃料电池以燃料甲醇来源丰富,价格低廉,储存、携带方便而成为近年的研究热点.评述了电极催化剂在直接甲醇燃料电池的研究概况,详细介绍了各种催化剂对甲醇氧化的作用.     

Silicon-based micro direct methanol fuel cell with an N-inputs-N-outputs anode flow pattern

A micro direct methanol fuel cell(μDMFC) is suitable for use in notebook computers,mobile phones,and other digital products.To resolve the poor mass-transport efficiency problem in the anode flow channel,this paper presents an N-inputs-N-outputs parallel flow pattern with rectangular convexes to reinforce methanol mass transport and reduce concentration polarization.The simulation results show that the N-inputs-N-outputs parallel flow channels with the rectangle convexes improve the performance.μDMFCs,which have four anode flow patterns,are fabricated using MEMS(microelectromechanical systems) technology.The experimental results show that the μDMFC with the rectangle convexes has a performance better than previously reported systems,and has a peak power density of 19.96 mW/cm2.The simulation and experimental results are in good agreement.     

基于钛网基膜电极组件的被动式直接甲醇燃料电池

基于钛网基膜电极组件（membrane electrode assembly,MEA）设计并制作被动式直接甲醇燃料电池（directmethanol fuel cell,DMFC）．钛网基MEA以钛金属网作为电极支撑体基底材料,Nafionll7作为质子交换膜．PtRU／XC-72R作为阳极催化剂,Pt／XC-72R作为阴极催化剂．被动式DMFC壳体采用有机玻璃材料制作．密封元件采用硅胶片制作．紧固件选用标准件．在室温空气自呼吸条件下,选取不同甲醇浓度的电解液．测试了基于钛网基MEA的被动式DMFC极化性能．结果表明：当电解液中甲醇浓度从0．5mol／L经过1．0mol／L增大到1．5mol／L时．基于钛网基MEA的被动式DMFC的功率密度峰值呈现先增大、后减小的规律;当甲醇浓度为1．0mol／L。电池功率密度峰值为3．91mW/cm2．     

Operational and structural aspects of a vapor-feed semi-passive direct methanol fuel cell supplied with concentrated methanol

Direct methanol fuel cell （DMFC） has great potential to replace the traditional battery in the field of portable power sources. This study investigates the operational and structural aspects of a vapor-feed semi-passive DMFC supplied with concentrated methanol. The effec tiveness of using vaporous methanol to improve the cell performance is experimentally validated. Results indicate that there exits an optimal value of methanol concentration that favors both methanol supply and control of methanol crossover （MCO）. With the increase in vaporization temperature, the cell performance can be enhanced. Based on the traditional structural design, a sintered porous metal plate is further used to depress the impact of MCO so that the cell performance can be significantly improved at a relatively higher methanol concentration. This is of great importance to enhance the energy density and operating duration for portable applications. The mechanisms related to the performance behaviors are discussed in detail.     

Promotion of catalytic activity for methanol electro-oxidation on CoPc-Pt/C co-catalysts

The catalytic activity for methanol electro-oxidation on CoPc-Pt/C co-catalysts, prepared by impregnation method, was studied in details through electrochemical methods. Cyclic voltammetry (CV) result demonstrates that CoPc has higher forward anodic peak current density and j _f /j _b value (forward anodic peak current density/backward anodic peak current density) than Pt/C. Chronoamperometry (CA) analysis indicates that CoPc-Pt/C exhibits both excellent transient current density and stable current density for methanol electro-oxidation compared with Pt/C. Two main mechanisms related to the promotion of catalytic activity are as follows: CoPc-Pt/C has the activity of tolerance to carbonaceous intermediates, thus inhibiting the self-poisoning of catalysts; CoPc-Pt/C owns prominent intrinsic catalytic activity indicated by the apparent activation energy for methanol oxidation on CoPc-Pt/C, which is 18 kJ/mol, less than that on Pt and PtRu catalysts as reported. Supported by the National Natural Science Foundation of China (Grant No. 20576106)     

直接甲醇燃料电池双极板冷却通道的热设计

将单个直接甲醇燃料电池的固体骨架看成开口系统,燃料电池稳定运行时的热负荷由阳极反应、阴极反应和甲醇直接氧化反应产生的3部分热量组成,利用热力学原理将其计算.在双极板上设置平行的冷却通道,将电池电化学反应产生的热量及时排出,有利于燃料电池的稳定运行.根据燃料电池中燃料、氧化剂的流向和冷却通道内冷却水流向的不同,冷却水和壁面的换热分别在恒热流密度和恒壁温热边界条件下进行.计算了2种情况下冷却通道壁面的温度和换热系数.结果表明,前者的换热效果要比后者好,但是,后者保证了工作层面具有恒定的温度,更有利于直接甲醇燃料电池的稳定运行.     

Synthesis and characterization of Pt-MoO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>-TiO<Subscript>2</Subscript> electrodes for direct ethanol fuel cells

To enhance the CO-tolerance performance of anode catalysts for direct ethanol fuel cells, carbon nanotubes were modified by titanium dioxide (donated as CNTs@TiO₂) and subsequently served as the support for the preparation of Pt/CNTs@TiO₂ and Pt-Mo/CNTs@TiO₂ electrocatalysts via a UV-photoreduction method. The physicochemical characterizations of the catalysts were carried out by using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy of adsorbed probe ammonia molecules. The electrocatalytic properties of the catalysts for methanol oxidation were investigated by the cyclic voltammetry technique. The results show that Pt-Mo/CNTs@TiO₂ electrode exhibits the highest performance in all the electrodes. It is explained that, the structure, the oxidation states, and the acid-base properties of the catalysts are influenced due to the strong interaction between Ti and Mo species by adding TiO₂ and MoO _x to the Pt-based catalysts.     

Electrochemical characterization of the Pt /PEDOT electrode in DMFC

Poly-(3, 4-ethylenedioxythiophene) (PEDOT) was applied in making electrodes and gas diffusion layer for direct methanol fuel cells (DMFC). Electrochemical characterizations of Pt/PEDOT electrodes, made by two different methods, were investigated by cyclic voltammetry, methanol oxidation tests and DMFC performance. The platinum particle structure in PEDOT/PSS (poly?styrene sulfonic acid) films was investigated by SEM and TEM. Our research work showed that PEDOT influenced the catalytic activity behavior in three different ways when it was applied to the anode, cathode and the gas diffusion layer. The DMFC performance agreed with the cyclic voltammetry and methanol oxidation test results.     

便携式直接甲醇燃料电池

采用超薄无Teflon化催化层制备直接甲醇燃料电池空气电极,用电化学沉积方法制备甲醇氧化催化剂PtRu／C。提出较高电位下甲醇氧化的概念。所研制的直接甲醇燃料电池的催化电极贵金属催化剂的利用率提高,甲醇氧化过程催化剂CO中毒问题能够基本消除。     

Synthesis and characterization of Pt-MoOx-TiO2 electrodes for direct ethanol fuel cells

To enhance the CO-tolerance performance of anode catalysts for direct ethanol fuel cells,carbon nanotubes were modified by titanium dioxide (donated as CNTs@TiO2) and subsequently served as the support for the preparation of Pt/CNTs@TiO2 and Pt-Mo/CNTs@TiO2 electrocatalysts via a UV-photoreduction method.The physicochemical characterizations of the catalysts were carried out by using X-ray diffraction (XRD),transmission electron microscopy (TEM),X-ray photoelectron spectroscopy (XPS),and infrared spectroscopy of adsorbed probe ammonia molecules.The electrocatalytic properties of the catalysts for methanol oxidation were investigated by the cyclic voltammetry technique.The results show that Pt-Mo/CNTs@TiO2 electrode exhibits the highest performance in all the electrodes.It is explained that,the structure,the oxidation states,and the acid-base properties of the catalysts are influenced due to the strong interaction between Ti and Mo species by adding TiO2 and MoOx to the Pt-based catalysts.