多孔聚乙酰苯胺纳米纤维载铂催化剂对甲醇的电催化氧化

采用简单的化学氧化聚合法制备了新型多孔结构的聚乙酰苯胺纳米纤维(np-PAANI), 并以此为载体在络合剂的存在下合成了Pt纳米微粒修饰的np-PAANI复合物膜电极C/np-PAANI/Pt. 样品的形貌和结构通过扫描电镜(SEM)、透射电镜(TEM)和X射线衍射(XRD)进行了表征. 在0.5 mol·L-1 CH3OH+0.5 mol·L-1 H2SO4混合溶液中考察了C/np-PAANI/Pt催化剂对甲醇的电催化氧化性能. 结果表明, 以np-PAANI负载的Pt催化剂对甲醇的电催化氧化活性和稳定性都比普通PAANI结构及石墨粉负载的Pt催化剂好很多.     

三维结构氧化石墨烯载铂催化剂对甲醇电催化性能

喷雾干燥法制备具有三维结构的氧化石墨烯(PGO),在其表面进一步负载活性成分Pt,得到纳米Pt/PGO复合催化剂。采用X射线粉末衍射(XRD)、透视电镜(TEM)和扫描电镜(SEM)等对催化剂的形貌和结构进行表征。结果表明,PGO具有类似于长4-6μm和宽2.0-3.0μm的三维纸团结构,平均粒径为4.2 nm的Pt纳米粒子均匀分布在其表面。采用循环伏安和计时电流法研究了在酸性溶液中催化剂对甲醇的电催化氧化性能。结果表明,Pt/PGO催化剂对甲醇呈现出更高的电催化氧化活性和稳定性。PGO所具有的三维结构和双功能作用机理有利于甲醇在铂表面的电催化氧化过程的发生。     

Pt/RuO2/CNTs纳米催化剂中RuO2含量对甲醇电催化氧化性能的影响

制备了一种新的甲醇直接燃料电池Pt/RuO2/CNTs阳极催化剂,在相同Pt负载量下,其甲醇电催化氧化活性是Pt/CNTs的3倍.采用循环伏安法研究发现Pt/RuO2/CNTs纳米催化剂中RuO2含量对甲醇电催化氧化活性有明显影响,当Pt和RuO2在碳纳米管上含量分别为15%和9.5%时,Pt/RuO2/CNTs催化剂具有最佳的甲醇电催化氧化活性.RuO2负载在碳纳米管上比电容的变化,反映了水合RuO2结构中质子与电子传输平衡的能力,分析表明,催化剂中RuO2含量不同导致电容的变化是影响甲醇电催化氧化活性的主要原因.当催化剂结构中质子与电子传输达到平衡时,催化剂比电容最大,电催化氧化活性最高.这种基于电容关联电催化剂的观点对甲醇直接燃料电池阳极催化剂的设计非常有意义.     

Pt 纳米颗粒在聚二甲基二烯丙基氯化铵功能化碳纳米管上的自发沉积及其对甲醇的电氧化性能

利用聚二甲基二烯丙基氯化铵(PDDA)非共价修饰的碳纳米管(CNTs)与PtCl₆^2-之间的自发氧化还原作用, 制备了Pt 纳米颗粒(Pt NPs)/CNTs-PDDA复合催化剂. PDDA在该催化剂中具有三种作用: (1) 作为金属前驱体PtCl₆^2-还原为Pt NPs 的还原剂; (2) 作为原位产生的Pt NPs 的稳定剂; (3) 在CNTs 表面形成保护膜抑制CNTs 在甲醇电催化氧化过程中的腐蚀. 采用傅里叶变换红外(FTIR)光谱、热重分析和拉曼光谱对CNTs-PDDA进行了表征, 表明PDDA通过π-π作用已成功覆盖在CNTs 表面, 并且修饰过程没有导致CNTs 结构的破坏. 采用透射电子显微镜(TEM)对Pt NPs/CNTs-PDDA 催化剂进行了表征, 结果表明, Pt NPs 均匀地分散在CNTs上, 平均粒径约2 nm, 且粒径分布范围窄. 用循环伏安法、计时电流法进一步考察了Pt NPs/CNTs-PDDA催化剂在酸性介质中对甲醇的电催化氧化的性能. 电化学测试结果表明, 与原始CNTs 负载的Pt NPs催化剂相比,Pt NPs/CNTs-PDDA催化剂具有更高的电化学活性表面积、电催化质量比活性和稳定性.     

纳米三氧化钨复合催化剂的制备及对甲醇电催化性能

采用浸渍沉淀法制备出WO₃-碳纳米管(WO₃-CNTs)纳米复合材料, 微波辅助乙二醇法在其表面负载活性成分Pt, 得到纳米Pt/WO₃-CNTs 催化剂. 采用X射线衍射(XRD), 透射电子显微镜(TEM)和X射线光电子能谱(XPS)等测试手段对催化剂的结构和形貌进行表征, 结果表明Pt 纳米粒子为面心立方晶体结构, 粒径大小在3-5 nm之间, 均匀地分布在WO₃-CNTs 纳米复合材料表面, 同时发现催化剂中的Pt 主要以金属态的形式存在. 采用循环伏安和计时电流法研究了在酸性溶液中Pt/WO₃-CNTs 催化剂对甲醇的电催化氧化性能, 结果表明Pt/WO₃-CNTs 催化剂比用硝酸处理的碳纳米管载铂催化剂(Pt/CNTs)对甲醇呈现出更高的电催化氧化活性和抗CO中毒性能.     

核壳结构碳化钨复合微球催化剂对甲醇电催化性能（英文）

以偏钨酸铵微球为前驱体,在不同反应时间和CO/CO_2气氛条件下,通过原位还原碳化反应制备了具有核壳结构碳化钨复合微球。采用X射线粉末衍射(XRD)、X射线光电子能谱(XPS)和扫描电镜(SEM)等对催化剂的形貌和结构进行了表征分析。硼氢化钠还原法将平均粒径为4.6 nm的Pt纳米粒子均匀分布在其表面,得到核壳结构碳化钨复合催化剂。采用循环伏安和计时电流法研究了在酸性溶液中催化剂对甲醇的电催化氧化性能。结果表明,与Pt/WC-15 h和JM Pt/C催化剂的电化学性能相比,Pt/WC-6 h催化剂对甲醇呈现出更高的电催化氧化活性和稳定性。碳化钨复合微球表面少量WO2成分的存在有利于甲醇在其表面的电催化氧化过程的发生。     

纳米三氧化钨修饰碳纳米管载铂催化剂对甲醇氧化的电催化性能

采用表面修饰技术将碳纳米管(CNT)表面羧基化, 通过羧基将钨离子基团修饰到碳纳米管的外表面, 再通过高温焙烧处理将钨离子基团氧化成WO₃, 成功合成了纳米WO₃/CNT复合物, 进一步还原Pt 的前驱体而得到Pt-WO₃/CNT复合催化剂. 采用X射线粉末衍射(XRD)和透射电镜(TEM)对样品的形貌和晶型结构进行了表征, 结果表明, Pt纳米粒子为面心立方晶体结构, 均匀地分布在WO₃修饰的碳纳米管表面. 采用循环伏安(CV)和计时电流法研究了在酸性溶液中Pt-WO₃/CNT催化剂对甲醇的电催化氧化活性, 结果表明WO₃修饰的碳纳米管载铂催化剂比用混酸处理的碳纳米管载铂催化剂对甲醇呈现出更高的电催化氧化活性和更好的稳定性.     

高利用率多壁碳纳米管负载金铂合金纳米粒子催化剂在碱性溶液中的甲醇电催化氧化性能研究

使用乙二醇还原法合成了一系列高利用率多壁碳纳米管负载的金铂双金属纳米粒子电催化剂,在碱性溶液中由循环伏安和计时电流法测试该AuPt催化剂对于甲醇氧化反应的电催化活性.透射电子显微镜、X射线衍射与X射线能谱观测催化剂形貌,表征催化剂结构.结果表明,金铂双金属纳米粒子均匀分散在碳纳米管上,催化剂具有良好甲醇电氧化性能.实验表明Au/Pt/MWCNTs比为10∶8∶32(bymass)时,该催化剂具有最高甲醇电氧化峰电流密度与最负起始氧化电位.     

具有优异甲醇催化氧化性能的Pt/MoO3-WO3/CNTs催化剂

以聚二烯丙基二甲基胺盐酸盐(PDDA)为连接剂,采用原位自组装方式将MoO3和WO3负载到碳纳米管(CNTs)上,然后通过乙二醇还原法负载Pt纳米颗粒,得到Pt纳米颗粒均匀分布的Pt/MoO3-WO3/CNTs催化剂.当氧化物总量控制在10 wt%,MoO3与WO3摩尔比为1:0.5时,Pt/MoO3-WO3/CNTs催化剂催化甲醇氧化活性最高,甲醇氧化峰电流If高达835 A/gPt.WO3和MoO3的加入提高了催化剂的甲醇氧化活性、抗CO中毒能力和稳定性,使得Pt/MoO3-WO3/CNTs催化剂表现出优异的甲醇电催化氧化性能.     

核壳结构碳化钨复合微球催化剂对甲醇电催化性能

以偏钨酸铵微球为前驱体,在不同反应时间和CO/CO₂气氛条件下,通过原位还原碳化反应制备了具有核壳结构碳化钨复合微球。采用X射线粉末衍射（XRD）、X射线光电子能谱（XPS）和扫描电镜（SEM）等对催化剂的形貌和结构进行了表征分析。硼氢化钠还原法将平均粒径为4.6 nm的Pt纳米粒子均匀分布在其表面,得到核壳结构碳化钨复合催化剂。采用循环伏安和计时电流法研究了在酸性溶液中催化剂对甲醇的电催化氧化性能。结果表明,与Pt/WC-15 h和JM Pt/C催化剂的电化学性能相比,Pt/WC-6 h催化剂对甲醇呈现出更高的电催化氧化活性和稳定性。碳化钨复合微球表面少量WO₂成分的存在有利于甲醇在其表面的电催化氧化过程的发生。     

A simple one-step preparation of high utilization AuPt nanoparticles supported on MWCNTs for methanol oxidation in alkaline medium

A simple one-step preparation of gold–platinum electrocatalysts supported on multi-walled carbon nanotubes (MWCNTs) with high utilization is reported. A low Pt loading series of bimetallic AuPt/MWCNTs catalysts were prepared by the improved ethylene glycol reduction method, and then they were compared in terms of the electrocatalytic activity for methanol oxidation using cyclic voltammetry (CV) and chronoamperometry in alkaline solutions. The structure of AuPt/MWCNTs was characterized by the transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The results showed high Pt utilization, uniform AuPt nanoparticles size and good electrocatalytic activity for methanol electro-oxidation. The effect of Au/Pt mass ratio on electrocatalytic activity was also investigated by CV and chronoamperometry. The highest peak current density, lowest onset potential and best anti-poisoning effect for methanol electro-oxidation appeared at the Au/Pt/MWCNTs mass ratio of 2:4:32.     

Synthesis of Pt and Pt-Fe nanoparticles supported on MWCNTs used as electrocatalysts in the methanol oxidation reaction

This work reports a feasible synthesis of highly-dispersed Pt and Pt-Fe nanoparticles supported on multiwall carbon nanotubes （MWCNTs） without Fe and multiwall carbon nanotubes with iron （MWCNTs-Fe） which applied as electrocatalysts for methanol electrooxidation. A Pt coordination complex salt was synthesized in an aqueous solution and it was used as precursor to prepare Pt/MWCNTs, Pt/MWCNTs-Fe, and Pt-Fe/MWCNTs using FeC12.4H20 as iron source which were named S 1, S2 and S3, respectively. The coordination complex of platinum （TOA）2PtC16 was obtained by the chemical reaction between （NH4）2PtC16 with tetraoctylammonium bromide （TOAB） and it was characterized by FT-IR and TGA. The materials were characterized by Raman spectroscopy, SEM, EDS, XRD, TEM and TGA. The electrocatalytic activity of Pt-based supported on MWCNTs in the methanol oxidation was investigated by cyclic voltammetry （CV） and chronoamperometry （CA）. Pt-Fe/MWCNTs electrocatalysts showed the highest electrocatalytic activity and stability among the tested electrocatalysts due to that the addition of ＂Fe＂ promotes the OH species adsorption on the electrocatalyst surface at low potentials, thus, enhancing the activity toward the methanol oxidation reaction （MOR）.     

Synthesis of Pt and Pt-Fe nanoparticles supported on MWCNTs used as electrocatalysts in the methanol oxidation reaction

This work reports a feasible synthesis of highly-dispersed Pt and Pt-Fe nanoparticles supported on multiwall carbon nanotubes (MWCNTs) without Fe and multiwall carbon nanotubes with iron (MWCNTs-Fe) which applied as electrocatalysts for methanol electrooxidation. A Pt coordination complex salt was synthesized in an aqueous solution and it was used as precursor to prepare Pt/MWCNTs, Pt/MWCNTs-Fe, and Pt-Fe/MWCNTs using FeCl₂·4NH₂O as iron source which were named S1, S2 and S3, respectively. The coordination complex of platinum (TOA)₂PtCl₆ was obtained by the chemical reaction between (NH₄)₂PtCl₆ with tetraoctylammonium bromide (TOAB) and it was characterized by FT-IR and TGA. The materials were characterized by Raman spectroscopy, SEM, EDS, XRD, TEM and TGA. The electrocatalytic activity of Pt-based supported on MWCNTs in the methanol oxidation was investigated by cyclic voltammetry (CV) and chronoamperometry (CA). Pt-Fe/MWCNTs electrocatalysts showed the highest electrocatalytic activity and stability among the tested electrocatalysts due to that the addition of ”Fe” promotes the OH species adsorption on the electrocatalyst surface at low potentials, thus, enhancing the activity toward the methanol oxidation reaction (MOR).     

Electrodeposition and electrocatalytic properties of platinum nanoparticles on multi-walled carbon nanotubes: effect of the deposition conditions

Platinum (Pt) nanoparticles were electrochemically deposited on multi-walled carbon nanotubes (MWCNTs) through a three-step process, including an electrochemical treatment of MWCNT, electro-oxidation of PtCl₄ ²⁻ to Pt(IV) complex, and an electro-conversion of Pt(0) on MWCNT. The effect of formation conditions for Pt(IV) complexes on the Pt nanoparticals transformed was investigated. The structure and elemental composition of the resulting Pt/MWCNT electrode were characterized by transmission electron micrograph (TEM) and energy dispersive X-ray spectroscopy (EDX). The electrocatalytic properties of the resulting Pt/MWCNT electrode for methanol oxidation have been investigated. The high electrocatalytic activity and good stability of Pt/MWCNT electrode may be attributed to the high dispersion of platinum nanoparticles and the particular properties of the MWCNT supports.     

Pyrolysis of chloroplatinic acid to directly immobilize platinum nanoparticles onto multi-walled carbon nanotubes

Platinum nanoparticles supported on multi-walled carbon nanotubes (Pt/MWCNTs) were first prepared by simple pyrolysis of H₂PtCl₆ solution. The structure of Pt/MWCNTs was characterized with X-ray diffraction (XRD), scanning electron microscope (SEM), and the results showed that the diameter of the obtained platinum nanoparticles immobilized on MWCNTs was below 50 nm, although the obtained platinum nanoparticles were not well uniformly dispersed on the surface of MWCNTs. The electrocatalytic performance of Pt/MWCNTs electrode for methanol oxidation reaction (MOR) was also investigated by linear sweep voltammetry (LSV), indicating that it was possible to employ the obtained platinum nanoparticles as anode material in fuel cell. Developing a novel and simple method to prepare platinum nanoparticles onto MWCNTs is the main contribution of this letter. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 8, pp. 1050–1053. The text was submitted the authors in English.     

一步法制备还原态氧化石墨烯载铂纳米粒子及其对甲醇氧化的电催化性能

以天然石墨为原料,采用改进的Hummers法制备氧化石墨.然后采用简单的一步化学还原法在乙二醇(EG)中同时还原氧化石墨烯(GO)和H₂PtCl₆制备高分散的铂/还原态氧化石墨烯(Pt/RGO)催化剂.采用傅里叶变换红外(FTIR)光谱、X射线衍射(XRD)和透射电子显微镜(TEM)对催化剂的微结构、组成和形貌进行表征.结果表明, GO已被还原成RGO, Pt纳米粒子均匀分散在RGO表面,粒径约为2.3 nm.采用循环伏安法和计时电流法评价催化剂对甲醇氧化的电催化性能,测试结果表明, Pt/RGO催化剂对甲醇氧化的电催化活性和稳定性与Pt/C和Pt/CNT相比有了很大提高.另外其对甲醇电催化氧化的循环伏安图中正扫峰电流密度(I_f)和反扫峰电流密度(I_b)的比值高达1.3,分别是Pt/C和Pt/CNT催化剂的2.2和1.9倍,表明Pt/RGO催化剂具有高的抗甲醇氧化中间体CO_ad的中毒能力.     

高催化活性Pd-Co3O4/MWCNTs催化剂对甲醇氧化的电催化性能

以Co(NO3)3·6H2O为钴源,聚乙二醇(PEG)20000为表面活性剂,与多壁碳纳米管(MWCNTs)混合后通过水热氧化法成功地合成了表面均匀分布纳米絮状Co3O4的MWCNTs复合物,进一步还原Pd的前驱体而制备得到Pd-Co3O4/MWCNTs复合催化剂.利用扫描电镜(SEM)、透射电镜(TEM)及X射线粉末衍射(XRD)等手段对样品的形貌和晶型结构进行了表征,结果表明Pd纳米粒子为面心立方晶体结构,均匀地分布在Co3O4修饰的MWCNTs表面.用循环伏安法和计时电流法表征结果表明:催化剂Pd-Co3O4/MWCNTs具有较大的电化学活性表面积,在碱性介质中对甲醇氧化具有更高的电催化活性和稳定性.研究结果表明,过渡金属氧化物纳米Co3O4颗粒在提高直接甲醇燃料电池(DMFC)催化性能研究中具有十分重要的作用,是一类很有潜力的载体催化剂.     

Ultrasonic assisted polyol synthesis of highly dispersed Pt/MWCNT electrocatalyst for methanol oxidation

A novel chemical method based on ultrasonic assisted polyol synthesis for the fabrication of highly dispersed Pt nanoparticles on multi-walled carbon nanotubes (MWCNTs) was developed. The simple and green method took only about 10 min at ambient temperature. The structure and chemical nature of the resulting Pt/MWCNT composites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray spectrometry (EDS). The results showed that the prepared Pt nanoparticles were uniformly dispersed on the MWCNT surface. The mean size of Pt nanoparticles was about 2.8 nm. Electrochemical properties of Pt/MWCNT electrode for methanol oxidation were examined by cyclic voltammetry (CV) and excellent electrocatalytic activities could be observed. The possible formation mechanism of Pt/MWCNTs was also discussed.     

Aucore Ptshell纳米粒子对甲醇氧化的电催化性能研究

应用两步化学还原法制备不同厚度的AucorePtshell纳米粒子,经紫外可见光谱(UV-V is)、透射电子显微镜(TEM)表征.该金纳米颗粒经化学还原包裹铂后平均粒径明显增大,调节金与铂的含量可获得不同包裹厚度的AucorePtshell纳米粒子.循环伏安法研究表明,粒径为70~80 nm的AucorePtshell纳米粒子对甲醇的氧化具有较好的电催化活性,并且其电催化性能随着电位循环扫描次数的增加而增强.