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通过调节微波反应溶液的pH值合成了一系列Mo修饰的Pt/C催化剂并用于乙醇的电氧化催化反应.利用X射线衍射(XRD)、透射电子显微镜(TEM)及X射线光电子能谱(XPS)对催化剂的晶型结构、微观形貌、粒径尺寸和表面电子结构进行了表征,并采用循环伏安法(CV)、计时电流法(CA)和电化学阻抗谱(EIS)对催化剂的乙醇电氧化催化性能进行了测试.结果表明,碱性环境有利于催化剂组分在碳载体上的均匀分布,pH值为14时制得的催化剂组分颗粒尺寸最小,且分布最均匀.该催化剂不仅表现出了最大的有效电化学比表面积和最高的乙醇电氧化催化活性,而且具有最稳定的乙醇氧化催化性能. 相似文献
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本文以还原氧化石墨烯(rGO)为载体制备了片状NiO/rGO和球形NiO/N-rGO结构的氧还原催化剂. 通过X-射线衍射(XRD)、Raman(拉曼)测试、X-射线光电子能谱(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等方法表征了两种催化剂的结构和形貌. 采用循环伏安法(CV)、Tafel曲线、线性扫描伏安法(LSV)、旋转圆盘电极(RDE)和旋转环盘电极(RRDE)等技术测试研究了两种催化剂的电化学催化氧还原性能. 研究结果表明,球形NiO/N-rGO催化剂催化氧还原的峰电流密度和起始电位(0.89 V vs. RHE)与商业化的Pt/C(20%)催化剂相近. 旋转圆盘电极(RDE)和旋转环盘电极(RRDE)测试证明,在碱性电解液中NiO/rGO和NiO/N-rGO催化的氧还原反应均主要通过4?鄄电子途径反应途径发生,球形NiO/N-rGO催化剂展现出替代Pt/C基催化剂的潜力. 相似文献
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以氯铂酸和亚碲酸钠为前驱体,采用两步法在醇水体系下得到负载型Pt1Te1金属间化合物前驱体,通过热处理得到负载型金属间化合物电催化剂Pt1Te1/XC-72.采用X射线衍射(XRD)、透射电子显微镜(TEM)、选区电子衍射(SAED)、电子能谱(EDS)和循环伏安方法(CV)对催化剂进行表征.结果表明:所得产物呈有序金属间化合物Pt1Te1结构,平均粒径4.5nm,在碳载体上具有很好的分散性;负载型金属间化合物电催化剂Pt1Te1/XC-72具有较高的电催化氧化甲醇活性,其优秀的催化氧化甲醇活性与Pt形成金属间化合物后所带来的几何及电子结构改变密切相关. 相似文献
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将CeO2溶胶与Pt/C催化剂机械混合制备了Pt-CeO2/C催化剂,研究了酸性条件下Pt-CeO2/C催化剂对甲醇氧化的电催化活性。结果表明,与Pt/C催化剂相比,Pt-CeO2/C催化剂对甲醇展现出更好的催化活性。XRD和TEM测试结果表明,Pt-CeO2/C催化剂中Pt与CeO2的平均粒径均为3~4 nm。对CeO2含量不同的Pt-CeO2/C催化剂在CH3OH-H2SO4中进行循环伏安测试发现,Pt-CeO2/C催化剂对甲醇氧化的电催化活性较高,其中Pt与CeO2质量比为1∶1时,催化剂的催化活性最高,对甲醇氧化的峰电流密度达到0.112 A/cm2。 相似文献
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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
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甲醇电氧化催化剂Pt/CeO2-CNTs与PtRu/C的比较研究 总被引:1,自引:0,他引:1
为认识合成催化剂Pt/CeO2-CNTs与商用催化剂PtRu/C(E-TEK)的催化性能和结构特点, 用CO溶出法和恒电位氧化法比较了这两种催化剂对CO的电氧化活性, 运用循环伏安法和恒电位氧化法比较了这两种催化剂对甲醇的电氧化活性. CO电氧化实验结果表明, PtRu/C上CO的电氧化活性明显优于Pt/CeO2-CNTs; 甲醇电氧化实验结果却表明, Pt/CeO2-CNTs与PtRu/C上甲醇电氧化表观活性相当. 为从结构特点上解释PtRu/C上CO电氧化和甲醇电氧化活性的不一致, 对PtRu/C进行了循环伏安扫描和CO溶出实验. 结果表明, PtRu/C的甲醇电氧化电流之所以没有预期高, 一是由于Pt比表面积不够大, 同时Pt-Ru之间协同作用有待提高. 本研究结果表明, 尽管Ru对Pt上CO电氧化有显著助催化作用, 但要充分发挥其对Pt上甲醇电氧化的助催化作用, 需同时提高Pt表面积和Pt-Ru接触界面. 该结论对设计甲醇电氧化催化剂具有普适意义. 相似文献
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热处理对甲醇电氧化催化剂PtRu/C性能的影响 总被引:1,自引:1,他引:0
采用非离子表面活性剂Triton X-100作为稳定剂制备了催化甲醇电氧化反应的PtRu/C催化剂, 研究了热处理温度对催化剂的组成、结构、形貌和活性的影响. 利用循环伏安法研究了PtRu/C催化剂催化甲醇电氧化的活性, 用热重和差热分析(TG-DTA)、X射线能量色散谱(EDX)、X射线衍射(XRD)、X射线光电子能谱(XPS)和透射电子显微镜(TEM)对PtRu/C催化剂进行了表征. 研究结果表明, 热处理对PtRu/C催化剂粒子的大小、分布和Pt的氧化态有重要的作用. 在350 ℃下热处理的催化剂显示了最好的催化甲醇电氧化的性能, 由Triton X-100作为稳定剂制备的PtRu/C催化剂最适宜的热处理温度是350 ℃. 相似文献
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应用离子交换法制备了40%Pt在Mo2C/GC上的电催化剂.X射线衍射(XRD)显示,Pt在Mo2C载体上有较好的分散度,平均粒径为3 nm.循环伏安、计时电位测试表明,酸性溶液中,Pt-Mo2C/GC具有良好的甲醇氧化性能.其催化甲醇氧化的起始电位比Pt/C的负移了90 mV.这一优异性能与Pt和载体Mo2C之间的协同作用有关.现场红外光谱电化学测量显示,甲醇在Pt/C电极氧化的中间产物是桥式吸附COB和线性吸附COL,而在Pt-Mo2C/GC电极则未检测到有害中间产物CO,其氧化终产物均为CO2. 相似文献
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Physical and electrochemical characterizations of microwave-assisted polyol preparation of carbon-supported PtRu nanoparticles 总被引:9,自引:0,他引:9
Liu Z Lee JY Chen W Han M Gan LM 《Langmuir : the ACS journal of surfaces and colloids》2004,20(1):181-187
PtRu nanoparticles supported on Vulcan XC-72 carbon and carbon nanotubes were prepared by a microwave-assisted polyol process. The catalysts were characterized by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy (XPS). The PtRu nanoparticles, which were uniformly dispersed on carbon, were 2-6 nm in diameter. All PtRu/C catalysts prepared as such displayed the characteristic diffraction peaks of a Pt face-centered cubic structure, excepting that the 2theta values were shifted to slightly higher values. XPS analysis revealed that the catalysts contained mostly Pt(0) and Ru(0), with traces of Pt(II), Pt(IV), and Ru(IV). The electro-oxidation of methanol was studied by cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. It was found that both PtRu/C catalysts had high and more durable electrocatalytic activities for methanol oxidation than a comparative Pt/C catalyst. Preliminary data from a direct methanol fuel cell single stack test cell using the Vulcan-carbon-supported PtRu alloy as the anode catalyst showed high power density. 相似文献
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直接甲醇燃料电池阳极催化剂PtRu/MWCNTs的水热合成及其电催化行为 总被引:1,自引:0,他引:1
采用水热法合成了PtRu/MWCNTs阳极催化剂,并以循环伏安、线性扫描、计时电流和交流阻抗等电化学测试研究了其对甲醇的电催化氧化,结果表明,水热合成的PtRu/MWCNTs较之同样条件下合成的PtRu/Vu lcan XC-72有更好的对甲醇氧化的催化活性和更强的抗毒化能力。 相似文献
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Effect of third metal on the electrocatalytic activity of PtRu/Vulcan for methanol electro-oxidation
The effect of a third metal on the activity of PtRu/Vulcan toward methanol oxidation reaction (MOR) is studied. An efficient
method to prepare ternary catalysts was used, which allows the introduction of the third metal to PtRu/Vulcan without altering
its particle size or dispersion. Ni, Mo, Co, and Ir were chosen and added to PtRu/Vulcan, based on theoretical and experimental
literature results, anticipating enhancement in the catalytic activity of PtRu/Vulcan. The composition of the third metal
can be varied from trace to considerable amounts. Transmission electron microscopy and energy-dispersive X-ray analysis were
used to determine the particle size, dispersion, and the composition of the ternary catalysts. Cylic voltammetry, chronoamperometry,
and CO-stripping voltammetry were used to analyze and compare the activities of the catalysts at 25 °C. It has been found
that the addition of even trace amounts of third metal significantly affects the catalytic activity of PtRu toward MOR. 相似文献
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Xingde Xiang Weishan Li Zhihui Zhou Zhao Fu Jianfei Lei Yuli Lin 《Journal of Solid State Electrochemistry》2010,14(5):903-908
A new electrocatalyst, Pt/HxMoO3-C, for methanol oxidation, was prepared by dispersing platinum nano-particles on Vulcan XC-72 modified by hydrogen molybdenum
bronze (HxMoO3, 0 ≤ x ≤ 2). The modification of Vulcan XC-72 with HxMoO3 on was accomplished by reducing the adsorbed molybdic acid and the platinum nano-particles were dispersed on the modified
carbon by reducing chloroplatinic acid, with formaldehyde as the reductant. The prepared Pt/HxMoO3-C was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersion spectrometer, cyclic
voltammetry (CV), chronoamperometry (CA), and single-cell test, with a comparison of the electrocatalyst, carbon-supported
platinum (Pt/C) prepared under the same condition but without the modification. The results obtained from XRD and SEM showed
that the modification of Vulcan XC-72 with HxMoO3 reduced the platinum particle size and improved distribution uniformity of platinum on carbon. The results, obtained from
CV, CA, and the single-cell test, showed that Pt/HxMoO3-C exhibited better electrocatalytic activity toward methanol oxidation than Pt/C. 相似文献
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Mohammad Ali Kamyabi Hoda Mohammadian Salma Jadali Mohsen Moharramnezhad 《Electroanalysis》2019,31(8):1484-1493
In this project, Pt/NiO?GO nanocatalyst is grown on nickel foam (NF) and, its catalytic activity towards electrochemical oxidation of methanol in acidic media is studied. The first step is devoted to the synthesis of NiO?GO support by a hydrothermal method. Then Pt nanoparticles (~34.3 nm) are electrodeposited on this supporting material. Hydrothermal and electrochemical deposition conditions are optimized. Surface of modified NF was inspected for physical characterization and Chemical composition by some techniques such as field emission scanning electron microscopy (FESEM), energy‐dispersive X‐ray spectra (EDS), and X‐ray diffraction (XRD). In the electrochemical section, the catalytic performance of Pt/NiO?GO/NF towards methanol oxidation is investigated by cyclic voltammetry and chronoamperometry measurements. The electrochemical impedance spectroscopy (EIS) is elected to deliberate charge transfer resistance on the catalyst surface. Mass activity, electrochemical surface area (ECSA) and durability of prepared catalysts are compared with commercial Pt/C. Deliberations prove the superiority of Pt/NiO?GO/NF towards methanol oxidation in acidic media. The Superior quality of synthesized nanocatalyst that is attributed to the synergetic effect of the NiO?GO support material and Pt nanoparticles, indicate that Pt/NiO?GO/NF can be successfully used as the anode in the direct methanol fuel cell (DMFC). 相似文献
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