共查询到20条相似文献,搜索用时 15 毫秒
1.
Ti基纳米TiO_2-CNT-Pt复合电极制备、表征及电化学性能 总被引:3,自引:0,他引:3
以电合成前驱体Ti(OEt)4直接水解法和电化学扫描电沉积法制备Ti基纳米TiO2-CNT-Pt(Ti/nanoTiO2-CNT-Pt)复合电极.透射电镜(TEM)和X射线衍射(XRD)测试表明,锐钛矿型纳米TiO2粒子(粒径5~10nm)和碳纳米管(CNT)结合形成网状结构,Pt纳米粒子(平均粒径9nm)均匀地分散在纳米TiO2-CNT复合膜表面.循环伏安及计时电流测试表明,Ti/nanoTiO2-CNT-Pt复合电极具有高活性表面,对甲醇的电化学氧化具有高催化活性和稳定性,Pt载量为0.32mg/cm2时,常温常压下甲醇氧化峰电流达到480mA/cm2. 相似文献
2.
Meltem Düdükcü Anya Beytaroğlu Nejat Yilmaz Fatih Köleli 《Russian Journal of Electrochemistry》2011,47(8):959-964
The catalytic behavior of stainless steel (SS) electrode modified by a thin film of polyaniline (PANI) containing platinum
particles was studied for electrooxidation of methanol and compared with a platinated Pt/PANI electrode in acidic aqueous
solution. Cyclic voltammetry (CV), chronoamperometry, CO stripping techniques were used to investigate electrochemical properties
and electrocatalytic activity of SS/PANI/Pt and Pt/PANI/Pt electrodes. The morphology and particle size of Pt catalysts were
characterized by Transmission Electron Microscopy (TEM) measurement. The effects of various parameters such as thickness of
polymer film, medium temperature and stability of the modified electrodes on methanol oxidation were also investigated. The
results indicated that the modified SS electrode exhibited a considerably high electrocatalytic activity on the methanol oxidation
as well as the modified Pt electrode. 相似文献
3.
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. 相似文献
4.
乙醇在Pt/nanoTiO2-CNT复合催化剂上的电催化氧化 总被引:10,自引:0,他引:10
通过前驱体Ti(OEt)4直接水解和电化学扫描电沉积法制备在Ti基体上的纳米TiO2-碳纳米管复合膜载Pt(Pt/nanoTiO2-CNT)复合催化剂. 透射电镜 (TEM) 和X射线衍射 (XRD) 结果表明, 锐钛矿型纳米TiO2粒子和Pt纳米粒子(粒径均为5~10 nm)均匀地分散在碳纳米管表面. 通过循环伏安和计时电流法研究表明, Pt/nanoTiO2-CNT 复合催化剂(Pt载量为0.32 mg•cm−2) 具有高达51.8 m2•g−1的电化学活性比表面积, 常温常压下对乙醇的电化学氧化具有高催化活性和稳定性, 乙醇氧化峰电位分别为0.59、0.96和0.24 V, 氧化峰电流密度分别达到−115、−113和−75 mA•cm−2. 复合催化剂对乙醇电氧化的高催化活性可归因于nanoTiO2、CNT和Pt纳米粒子的协同催化作用. 相似文献
5.
Carbon ceramic electrode, a new electrode substrate, was prepared by sol–gel procedure and used for the electropolymerization
of o-phenylenediamine and incorporation of platinum nanoparticles into the resulting poly(o-phenylenediamine) (PoPD) film. The modified electrode was used for electrooxidation of methanol in 0.3 M H2SO4 as supporting electrolyte. The presence of PoPD film increased considerably the efficiency of deposited Pt nanoparticles
toward the electrocatalytic oxidation of methanol. The effective parameters on the electrooxidation of methanol, i.e., amounts
of polymer and Pt catalyst, medium temperature, working potential limit in anodic direction, and potential scan rate, were
investigated, and the results were discussed. 相似文献
6.
Tang H Chen J Nie L Liu D Deng W Kuang Y Yao S 《Journal of colloid and interface science》2004,269(1):26-31
Highly dispersed platinum nanoparticles were electrodeposited on graphitic carbon nanofibers (GCNFs) by cyclic voltammetry (CV) in 7.7 mM H2PtCl6+0.5 M HCl aqueous solutions. The graphitic carbon nanofibers (GCNFs) used in this paper were grown directly on a graphite disk by chemical vapor deposition (CVD). The micrographs and element composition of Pt/GCNFs/graphite electrode were characterized by scanning electron microscopy (SEM) and electron diffraction spectroscopy (EDS). The electrocatalytic properties of Pt/GCNFs/graphite electrode for methanol oxidation have been investigated by CV and excellent electrocatalytic activity can be observed even at very low platinum loading (md=8.79 microg cm(-2)). The highest mass activity (MA) for methanol oxidation reaches 323 Ag(-1) when Pt/GCNFs/graphite electrode was cycled at a sweep rate of 50 mVs(-1) by CV in 2 M CH3OH+1 M H2SO4 aqueous solutions. This may be attributed to the small particle size and high dispersion of platinum particles coated on GCNFs and shows good potential application in direct methanol fuel cell (DMFC). Additionally, the long-term cycling stability of platinum catalysts was also investigated. 相似文献
7.
Jin Shi Xin-Sheng Li Yu-Qi Hu Yi-Xin Hua 《Journal of Solid State Electrochemistry》2008,12(12):1555-1559
A new method to electro-deposit platinum nanoparticles on the surface of multi-walled carbon nanotubes (MWNTs) functionalized
with 4-mercaptobenzene has been described. X-ray photoelectron spectroscopy results reveal that 4-mercaptobenzene was attached
to the surface of MWNTs. Transmission electron microscope and X-ray diffraction analysis confirm that platinum nanoparticles
were highly dispersed on the surface of MWNTs, and the average size of the platinum particle is 4.2 nm. The electrocatalytic
properties of the Pt/MWNT composite electrode for methanol oxidation were investigated by cyclic voltammetry, and the results
show that the fabricated composites exhibit high catalytic activity and good long-term stability. The study provides a feasible
approach to fabricate Pt/MWNT composite electrode for direct methanol fuel cell. 相似文献
8.
团聚铂纳米粒子电极在甲醇氧化中的电催化特性 总被引:7,自引:0,他引:7
用H2还原法并以Nafion作为稳定剂合成团聚的Pt纳米粒子,附载于玻碳表面制备电催化剂.透射电子显微镜(TEM)和扫描电子显微镜(SEM)表征结果指出,团聚Pt纳米粒子的平均尺寸约为400 nm.运用电化学循环伏安法(CV)和原位傅立叶变换红外反射光谱(in situ FTIRS)研究甲醇的氧化过程,发现团聚Pt纳米粒子电极具有较高的电催化活性.原位FTIRS研究结果检测到甲醇在所制备的电催化剂上氧化的中间体为线型吸附态CO物种,其红外吸收给出异常红外效应的光谱特征. 相似文献
9.
《Electrochemistry communications》2008,10(11):1748-1751
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. 相似文献
10.
Nickel foam and five nickel foam-based composite electrodes were prepared for being used as anode materials for the electrooxidation
of methanol in KOH solution containing 0.1 and 1.0 M of methanol. The layered electrodes composed of nickel foam, platinum
nanoparticles, polyaniline (PANI) and/or porous carbon (C) prepared in various assemblies. As shown by SEM analysis, depending
on the preparation conditions, the electrodes of different morphologies were obtained. Using the cyclic voltammetry method,
the oxidation of methanol on nickel foam electrode was observed in the potential range 0.4 V ↔ 0.7 V, where the Ni(OH)2/NiOOH transformation occurred. The presence of Pt particles in electrode gave rise to the increase in electrocatalytic activity
in this potential range. For electrodes containing dispersed platinum catalyst (Ni/Pt, Ni/PANI/Pt and Ni/C/Pt), the oxidation
of methanol was noted also in the potential range −0.5 V ↔ 0.1 V. The electrocatalytic activities of the examined electrodes
toward methanol oxidation at low potentials were in order Ni/Pt > Ni/C/Pt > Ni/PANI/Pt, whereas at high potentials in order
Ni/PANI/Pt > Ni/Pt> Ni/C/Pt > Ni. Among the examined electrodes, the most resistant to cyclic poisoning appeared to be the
Ni/C/Pt electrode.
Presented at the 4Th Baltic Conference on Electrochemistry, Greifswald, March 13–16, 2005 相似文献
11.
甲醇在铂修饰的氧化钛电极上电催化氧化行为的研究 总被引:8,自引:0,他引:8
运用电化学方法评价了电化学阴极还原-阳极氧化两步法制得的以钛为基体的铂修饰的钛氧化物(Pt-TiOx/Ti)电极对甲醇电催化氧化的性能,结果表明,制得的修饰电极对甲醇氧化呈现了很高的电催化活性和好的稳定性.通过X光电子能谱(XPS)、扫描隧道显微镜(STM)和现场傅立叶变换红外(FTIR)反射光谱等技术,发现修饰电极对甲醇氧化具有高的电催化性能,可归属于纳米级Pt粒子在TiOx中的高度分散及由于Pt和TiOx的相互作用,使电极表面对甲醇氧化中间产物CO的吸附量大大降低. 相似文献
12.
Chen QS Sun SG Zhou ZY Chen YX Deng SB 《Physical chemistry chemical physics : PCCP》2008,10(25):3645-3654
CoPt nanoparticles supported on a glassy carbon electrode (denoted as CoPt/GC) were prepared by galvanic replacement reaction between electrodeposited Co nanoparticles and K(2)PtCl(6) solution. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were both employed to characterize the CoPt nanoparticles. It was shown that the CoPt nanoparticles have irregular shapes and most of them exhibit a core-shell structure with a porous Co core and a shell of Pt tiny particles. The composition of the CoPt nanoparticles was analyzed by energy-dispersive X-ray spectroscopy (EDX), which depicts a Co : Pt ratio of ca. 21 : 79. Studies of cyclic voltammetry (CV) demonstrated that CoPt/GC possesses a much higher catalytic activity towards CO and methanol electrooxidation than a nanoscale Pt thin film electrode. In situ FTIR spectroscopic studies have revealed for the first time, that a CoPt nanoparticles electrode exhibits abnormal IR effects (AIREs) for IR absorption of CO adsorbed on it. In comparison with the IR features of CO adsorbed on a bulk Pt electrode, the direction of the IR bands of CO adsorbed on the CoPt/GC electrode is inverted completely, and the intensity of the IR bands has been enhanced up to 15.4 times. The AIREs is significant in detecting the adsorbed intermediate species involved in electrocatalytic reactions. The results demonstrated a reaction mechanism of CH(3)OH oxidation on CoPt/GC in alkaline solutions through evidencing CO(L), CO(M), HCOO(-), CO(3)(2-), HCO(3)(-) and CO(2) as intermediate and product species by in situ FTIRS. 相似文献
13.
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. 相似文献
14.
采用溶胶-凝胶和电沉积法制备Ti基纳米TiO2-Pt(Ti/纳米TiO2-Pt)修饰电极. X射线衍射(XRD)表明纳米TiO2为锐钛矿型, 扫描电镜(SEM)显示Pt纳米粒子在纳米TiO2多孔膜的表面呈现簇分散状态, 平均粒径约25 nm. 通过循环伏安(CV)和计时电流法研究了Ti/纳米TiO2-Pt修饰电极对乙二醛直接电氧化的电催化活性, 结果表明, 修饰电极对乙二醛的直接电氧化呈现良好的催化活性, 在0.60和1.23 V(vs SCE)出现两个氧化峰, 二者电流密度分别为16 和42 mA·cm-2, 约为纯Pt电极的2倍和1.5倍, 反应过程受浓差扩散控制. 相似文献
15.
In this work, we examine the electrocatalytic activity of electrodeposited Platinum (Pt)-Nickel (Ni) alloy layers on an inert substrate electrode for methanol oxidation reaction. Analyses using energy-dispersive fluorescent X-ray analysis and powder X-ray diffractometry confirm alloying of Pt with Ni in a range of compositions. Steady-state polarisation measurements in 0.5 M methanol+0.5 M H2SO4
solutions clearly show that the onset of electro-oxidation shifts to less anodic potential values (approximately 160 mV), while also exhibiting current enhancements up to ~15 times the currents obtained for the pure Pt electrodeposit. A linear relationship between the cyclic voltammetric peak (oxidation) current and [MeOH] is observed at a scan rate of 50 mVs–1, thus indicating reduced influence of adsorbed CO (COads) surface poison. A critical composition, Pt (92%)/Ni (8%) [denoted Pt-Ni(3) alloy] is found to exhibit maximum electrocatalytic activity, beyond which the activity drops, whereas pure Ni does not catalyse the reaction. While the promotion of electro-oxidation is understood to be
largely due to the alloy catalyst, surface redox species of Ni oxide formed during the electro-oxidation process may also contribute to the oxygenation of COads, thereby enhancing the oxidation current. Plausible mechanisms of methanol oxidation on Pt/ transition metal alloy electrocatalysts are discussed in terms of electron transfer (in the alloy) and the role of Ni oxide species. 相似文献
16.
Wang H Alden L Disalvo FJ Abruña HD 《Physical chemistry chemical physics : PCCP》2008,10(25):3739-3751
The electrocatalytic activities and mechanisms of PtPb and PtBi ordered intermetallic phases towards formic acid, formaldehyde and methanol oxidation have been studied by DEMS and FTIRS, and the results compared to those for a pure polycrystalline platinum electrode. While PtPb exhibits an enhanced electrocatalytic activity for the oxidation of all three organic molecules when compared to a Pt electrode, PtBi exhibits an enhanced catalytic activity towards formic acid and formaldehyde oxidation, but not methanol. FTIRS data indicate that adsorbed CO does not form on PtPb or PtBi intermetallic compounds during the oxidation of formic acid, formaldehyde and methanol, and therefore their oxidation on both PtPb and PtBi intermetallic compounds proceeds via a non-CO(ads) pathway. Quantitative DEMS measurements indicate that only CO(2) was detected as a final product during formic acid oxidation on Pt, PtPb and PtBi electrodes. At a smooth polycrystalline platinum electrode, the oxidation of formaldehyde and methanol produces mainly intermediates (formaldehyde and formic acid), while CO(2) is a minor product. In contrast, CO(2) is the major product for formaldehyde and methanol oxidation at a PtPb electrode. The high current efficiency of CO(2) formation for methanol and formaldehyde oxidation at a PtPb electrode can be ascribed to the complete dehydrogenation of formaldehyde and formic acid due to electronic effects. The low onset potential, high current density and high CO(2) yield make PtPb one of the most promising electrocatalysts for fuel cell applications using small organic molecules as fuels. 相似文献
17.
18.
丙醇和丁醇异构体在钯镍电极上的电催化氧化 《燃料化学学报》2013,41(10):1274-1280
β环糊精(β-CD)具有特殊的空腔结构,将β-CD修饰的多壁碳纳米管(MWCNT)涂在钛基底上,采用电沉积的方法在修饰的钛基底上沉积纳米PdNi催化剂。SEM结果表明,PdNi纳米颗粒在β-CD/MWCNT修饰的钛片上有较好的分散度,粒径为90~130 nm。在碱性溶液中,测试了PdNi-β-CD/MWCNT/Ti电极分别对丙醇和丁醇不同异构体氧化的电催化活性;通过计算与-OH相连的碳原子上的Muliken净电荷,分析不同异构体的氧化机理。结果表明,不同异构体的氧化活性不同,PdNi-β-CD/MWCNT/Ti电极对正丙醇和正丁醇的氧化活性明显高于其异构体,-OH所在碳原子上的Muliken 净电荷越小,醇类分子越容易被氧化。 相似文献
19.
Iman Razavipanah Gholam Hossein Rounaghi Mohammad Hossien Arbab Zavvar 《Journal of the Iranian Chemical Society》2013,10(6):1279-1289
A nanocatalyst coating was prepared at surface of a glassy carbon electrode by electropolymerization of pyrrole by cycling the electrode potential between ?0.8 and 0.8 V (vs. Ag/AgCl). Then, polypyrrole film was potentiostatically coated with platinum nanoparticles at constant potential of ?0.2 V (vs. Ag/AgCl). The resulting electrode was denoted as GCE/PPy/Pt. This modified electrode was characterized by IR, SEM, TEM and EDX. The electrocatalytic oxidation of ethanol at the GCE/PPy/Pt has been investigated using cyclic voltammetric and chronoamperometric methods. The effects of various parameters on electrocatalytic oxidation of the ethanol, such as the thickness of PPy film, the amount of platinum nanoparticles, ethanol concentration, potential scan rate and working potential limit in anodic direction, were investigated. The kinetic of the ethanol oxidation is discussed on the GCE/PPy/Pt. The stability and reproducibility of this modified electrode were also studied. 相似文献
20.
Biuck Habibi Mohammad Hossien Pournaghi-Azar 《Journal of Solid State Electrochemistry》2010,14(4):599-613
Electrochemically platinum plated aluminum (Al/Pt) was used as an electrode substrate for the electropolymerization of aminophenols
and fabrication of composite electrodes based on platinum nano-particles. The poly(o-aminophenol) (PoAP), poly(m-aminophenol) (PmAP), and poly(p-aminophenol) (PpAP) were synthesized on the Al/Pt electrode, and further modification was performed by deposition of platinum nano-particles
onto polymer matrixes. The electrochemical and morphological characteristic of the composed electrodes were carried out by
cyclic voltammetry and scanning electron microscopy, respectively. The electrocatalytic oxidation of methanol on the composite
electrodes was studied by cyclic voltammetry in 0.1 M sulfuric acid as supporting electrolyte. It was found that the Al/Pt/PoAP electrode incorporated Pt nano-particles (Al/Pt/PoAP/Pt) exhibits a higher electrocatalytic activity for the oxidation of methanol than the Al/Pt/PmAP/Pt and Al/Pt/PpAP/Pt electrodes. On the other hand, a higher catalytic current for methanol oxidation was found on the Al/Pt/PoAP/Pt electrode in comparison to bulk Pt and Al–Pt (Al with 0.2 mg cm−2 of Pt particles) electrodes. The effects of various parameters such as thickness of the polymer film, concentration of the
monomer, Pt loading method and the Pt amounts, concentration of the methanol, and the medium temperature were studied on the
electrooxidation of methanol. The long-term stability of the modified electrode has also been investigated. 相似文献