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1.
In this work, PdAu nanocatalysts with different weight ratio of Pd and Au supported on functional multi-walled carbon nanotubes (f-MWCNTs) were prepared, and their electrocatalytic activity for the oxidation of formic acid was also studied. The electrocatalysts were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electrochemical results showed that the 4Pd1Au/f-MWCNTs (by weight) catalyst, exhibited distinctly higher activity and better stability in formic acid electrooxidation than the Pd/f-MWCNTs catalyst. The Nano-Au improves potentially the performance of Pd-based electrocatalysts for the direct formic acid fuel cells (DFAFCs). 相似文献
2.
Gaixiu Yang Yu Chen Yiming Zhou Yawen Tang Tianhong Lu 《Electrochemistry communications》2010,12(3):492-495
The carbon supported Pd–P (Pd–P/C) anodic catalyst in direct formic acid fuel cell (DFAFC) was prepared with a novel phosphorus reduction method. The Pd–P/C catalyst obtained possesses the high content of P0 in the alloying state. Because alloying P0 could decrease the 3d electron density of Pd and the adsorption affinity of CO and H on Pd, alloying P0 would promote the formic acid (FA) oxidation through the direct pathway. Therefore, the electrocatalytic performance of the Pd–P/C catalyst for the FA oxidation is much better than that of the Pd/C catalyst. 相似文献
3.
Ruoshi Li Hao Hao Wen-Bin Cai Tao Huang Aishui Yu 《Electrochemistry communications》2010,12(7):901-904
Pd–Pb hollow nanospheres dispersed on carbon black were developed by a galvanic replacement reaction between sacrificial cobalt nanoparticles and Pd2+, Pb2+ ions. The as-prepared catalysts were characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The electrochemical measurements show that the as-prepared catalysts have excellent catalytic activity for formic acid electrooxidation, which is attributed to the large surface area caused by the hollow structure and the lead doping effect which might modify the electronic structure of the catalysts. 相似文献
4.
Chen Qihang Zhou Qianqian Li Ting-Ting Liu Runze Li Hongwei Guo Fenya Zheng Yue-Qing 《Transition Metal Chemistry》2019,44(4):349-354
Transition Metal Chemistry - We have successfully prepared two ruthenium-based covalent bonding photosensitizer–catalyst dyads through a simple procedure. 1H NMR spectra of both dyads show... 相似文献
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《Electrochemistry communications》2001,3(2):81-85
In current-control experiments, perturbing an aqueous solution containing 0.10 M formic acid and 0.50 M HClO4 by including a small amount of HBF4 causes more than a 60% increase in the value of the applied current for which low-valued stationary potentials remain stable. The current increases by more than 50% at relevant potential values in potential-control experiments. Current–potential characteristics inferior to those of the HCOOH + HClO4 solution are obtained with other solutions made by adding small amounts of a strong acid or salt. Properties that exist among the anions present in the latter solutions are possessed by BF4−. Nonlinear behavior exhibited by formic acid oxidation is changed drastically by the presence of a small amount of any one of the anions studied. These results and other arguments support the hypothesis that HBF4 enhances current–potential characteristics by causing the formation of surface anion complexes possessing OH components at low potentials. 相似文献
7.
Stochastic resonance (SR) is shown in a two-parameter system, a model of electrochemical oxidation of formic acid on Pt. The driving current and the saturation coverage for carbon monoxide are two control parameters in this model. Modulation of an excitable focal stable state close to a Hopf bifurcation by a weak periodic signal in one parameter and noise in the other parameter is found to give rise to SR. The results indicate that the noise can enlarge a weak periodic signal and lead the system to be ordered. The scenario and novel aspects of SR in this system are discussed. 相似文献
8.
Surin Saipanya Li Fang Suwaphid Themsirimongkon Suphitsara Maturost Natthapong Pongpichayakul Napapha Promsawan Paralee Waenkaew 《先进技术聚合物》2023,34(1):120-133
The aim of this research was to study the efficiency of polyvinyl alcohol (PVA)-modified graphene oxide (GO) as a supporting material for catalysts that oxidize formic acid. The active metal catalysts (e.g., Pt and Pd) were electrodeposited on PVA/GO surfaces. The morphologies of the prepared catalysts were characterized by scanning electron microscopy and transmission electron microscopy, while their chemical compositions were identified by X-ray diffraction and X-ray photoelectron spectroscopy. The results show that compared with the other catalysts on GO, the prepared active PtPd alloy catalyst nanoparticles with 11.49–20.73 nm sizes were well dispersed on the PVA/GO surfaces. Electrochemical results indicate that the activities of the catalysts with PVA provided a higher current density than that of the catalysts without PVA. The bimetallic 3Pt3Pd/PVA/GO catalyst showed the greatest catalytic activity, stability, and CO oxidation when compared to those of other catalysts. The electronic, morphological, and structural properties promote the mass-charge transfer through the interaction. These results indicate that the PVA-modified GO provides a suitable site for active bimetallic catalyst surfaces, resulting in excellent formic acid oxidation and high CO elimination. The 3Pt3Pd/PVA/GO electrocatalyst is promising for enhancing formic acid oxidation. 相似文献
9.
Ya Wen TANG Shuang CAO Ling Ling ZHANG Jian Chun BAO Ping ZHOU Tian Hong LU 《中国化学快报》2006,17(12):1623-1626
The performance of the direct formic acid fuel cell (DFAFC) is considerably higher than the direct methanol fuel cell (DMFC) because of some characteristics of formic acid1. For example, formic acid is non-toxic. Formic acid has two orders of magnitude smaller crossover flux through a Nafion membrane than methanol2. In DFAFC, the concentration of formic acid can be as high as 20 mol/L, while the best concentration of methanol in DMFC is only about 2 mol/L3. Thus, the power density of … 相似文献
10.
N. A. Yashtulov M. V. Lebedeva N. V. Myasnikova A. V. Ragutkin V. R. Flid 《Russian Chemical Bulletin》2017,66(3):474-478
The platinum-palladium/Nafion metal—polymer nanocomposites were synthesized by chemical reduction of metal ions in water—organic reverse microemulsion solutions. The catalytic activity of the synthesized polymer composites with bimetallic Pt—Pd nanoparticles was estimated in the oxidation of hydrogen and formic acid. 相似文献
11.
Fereshteh Chekin Samira Bagheri Sharifah Bee Abd Hamid 《Journal of Solid State Electrochemistry》2014,18(4):893-898
This work reports the preparation, characterization, and electrocatalytic characteristics of a new metallic nanocatalyst. The catalyst, Pt black–graphene oxide (Pt-GO), was prepared by deposition of Pt black on the surface of graphene oxide nanosheet and characterized by transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), and voltammetry. The Pt-graphene (Pt-GR) composite modified glassy carbon electrode (Pt-GR/GCE) was prepared with cyclic voltammetric scanning of Pt-GO/GCE in the potential range from ?1.5 to 0.2 in 0.1 M phosphate buffer solution at 50 mV·s?1 for 5 cycles. The electrocatalytic properties of the Pt-GR/GCE for methanol (CH3OH) oxidation have been investigated by cyclic voltammetry (CV); high electrocatalytic activity of the Pt-GR/GCE can be observed. This may be attributed to the high dispersion of Pt catalyst and the particular properties of GR support. The long-term stability of Pt-GR composite was investigated in 0.05 M CH3OH in 0.1 M H2SO4 solution. It can be observed that the peak current decreases gradually with the successive scans. The loss may result from the consumption of methanol during the CV scan. It also may be due to the poisoning organic compounds. The results imply that the Pt-GR composite has good potential applications in fuel cells. 相似文献
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Electrospun carbon nanofiber-supported bimetallic PtxAu100?x electrocatalysts (PtxAu100?x/CNF) were prepared by electrochemical codeposition method. The composition of PtAu bimetallic nanoparticles could be controlled by varying the ratio of H2PtCl6 and HAuCl4. Scanning electron microscopy images showed that bimetallic nanoparticles had coarse surface morphology with high electrochemically active surface areas. X-ray diffraction analysis testified the formation of PtAu alloys. PtxAu100?x/CNF electrocatalysts exhibited improved electrocatalytic activities towards formic acid oxidation by providing the selectivity of the reaction via dehydrogenation pathway and suppressing the formation/adsorption of poisoning CO intermediate, indicating that PtxAu100?x/CNF is promising electrocatalyst in direct formic acid fuel cells. 相似文献
14.
Jeong Young Eun Kumar Pullur Anil Ha Heon Phil Lee Kwan-young 《Research on Chemical Intermediates》2018,44(11):6803-6829
Research on Chemical Intermediates - Herein, we investigated the NOx reduction performance of Sb–V–CeO2/TiO2 (SbVCT) catalyst subjected to hydrothermal aging, where 6 vol% of H2O was... 相似文献
15.
Julie L. S. Bell David J. Wesolowski Donald A. Palmer 《Journal of solution chemistry》1993,22(2):125-136
The dissociation quotients of formic acid were measured potentiometrically from 25 to 200°C in NaCl solutions at ionic strengths of 0.1, 0.3 1.0, 3.0, and 5.0 mol-kg–1. The experiments were carried out in a concentration cell with hydrogen electrodes. The resulting molal acid dissociation quotients for formic acid, as well as a set of infinite dilution literature values and a calorimetrically-determined enthalpy of reaction, were fitted by an empirical equation involving an extended Debye Hückel term and seven adjustable parameters involving functions of temperature and ionic strength. This regressional analysis yielded the following thermodynamic quantities for 25°C: logK=–3.755±0.002, Ho=–0.09±0.15 kJ-mol–1, So=–72.2±0.5 J-K–1-mol–1, and C
p
o
=–147±4 J-K–1-mol–1. The isocoulombic form of the equilibrium constant is recommended for extrapolation to higher temperatures. 相似文献
16.
Tian Yongmei Huang Jichun Gao Yuan Cao Dianxue Wang Guiling 《Journal of Solid State Electrochemistry》2012,16(5):1901-1906
Fe–N–C catalysts were prepared through metal-assisted polymerization method. Effects of carbon treatment, Fe loading, nitrogen
source, and calcination temperature on the catalytic performance of the Fe–N–C for H2O2 electroreduction were measured by voltammetry and chronoamperometry. The Fe–N–C catalyst shows optimal performance when prepared
with pretreated active carbon, 0.2 wt.% Fe, paranitroaniline (4-NA) and one-time calcination. The Fe–N–C catalyst displayed
good performance and stability for electroreduction of H2O2 in alkaline solution. An Al–H2O2 semi-fuel cell was set up with Fe–N–C catalyst as cathode and Al as anode. The cell exhibits an open-circuit voltage of 1.3 V
and its power density reached 51.4 mW cm−2 at 65 mA cm−2. 相似文献
17.
Elena V. Ovchinnikova Galina Ya. Popova Tamara V. Andrushkevich 《Reaction Kinetics and Catalysis Letters》2009,96(1):91-100
A kinetic model for the β-picoline oxidation over vanadia-titania catalyst is presented. The model covers the reaction mechanism,
temperature dependences and a system of kinetic equations. The activation energies and constants in these equations are calculated. 相似文献
18.
Mohammad-Saleh Zabihi Jahan Bakhsh Raoof Mahmoud Reza Sohrabi Sayed Reza Hosseini Fatemeh Farrash Bamoharram 《Journal of the Iranian Chemical Society》2016,13(11):2093-2101
Phosphotungstic acid (PWA) was used for accumulation of nickel ions at the carbon paste electrode for preparation of PWA-modified CPE (PWA/CPE). The PWA was evenly mixed with graphite powder and paraffin oil. Then, for preparation of Ni/PWA/CPE, Ni ions were included onto the PWA/CPE surface through immersion method at open circuit condition. The scanning electron microscopy (SEM), energy-dispersive spectroscopy and electrochemical methods were used to verify the prepared electrodes. The SEM images reveal that morphology of the CPE was influenced by PWA addition. Application of the Ni/PWA/CPE for methanol oxidation was explored by various electrochemical techniques. Electrochemical response of methanol oxidation at the surface of Ni/PWA/CPE was 2.5 times higher than that Ni/CPE. The obtained results indicated that the modified electrode exhibited high electrocatalytic activity toward methanol oxidation. Then, catalytic rate constant was found to be 8.25 × 104 cm3 mol ?1 s?1 using chronoamperometry method. Furthermore, the effects of several parameters, such as PWA loading, NiSO4 concentration, accumulation time and methanol concentration toward methanol oxidation at the surface of this modified electrode as well as stability, have been investigated. 相似文献
19.
Pamela Moyo Tawanda Mugadza Gift Mehlana Upenyu Guyo 《Research on Chemical Intermediates》2016,42(8):6511-6529
We report on the synthesis and characterization of activated carbon–ethylenediamine–cobalt(II) tetracarboxyphthalocyanine conjugate (AC–CONHCH2CH2NH2–CoPc) and its electrocatalytic behavior for oxidation of ascorbic acid. Ultraviolet–visible (UV–Vis), Fourier-transform infrared (FTIR), and electrochemical impedance spectroscopies, and cyclic and square-wave voltammetry were used to characterize the electrode modifiers and modified glassy carbon electrode. The limit of detection was found to be 0.26 µm using 3δ notation. The linear dynamic range was from 1.5 × 10?4 to 1 × 10?2 M with electrode sensitivity of 0.01 A mol?1 L cm?2. A Tafel slope of 200.8 mV decade?1 was found. The concentration of ascorbic acid in the tablet was 0.034 M. Oxalic acid showed no interference in ascorbic acid determination. 相似文献
20.
《Journal of Molecular Catalysis #》1992,71(3):303-315
The electrocatalytic activity of several types of polypyrrole films bearing cationic pendant group [tris(bipyridyl)ruthenium(II) complexes, viologen, ammonium] and containing dispersed microparticles of RuO2 towards the oxidation of alcohols to aldehydes or ketones has been investigated. Best results are obtained with polypyrrole films substituted by a tris(bipyridyl)ruthenium(II) complex, the latter acting as an electron relay for the electrogeneration of the strong oxidizing species RuO42−. The influence of several parameters such as base, supporting electrolyte, electrolysis potential and catalyst amount on the efficiency of the electrocatalysis has been examined. Under optimum conditions a maximum turnover of 10 900 was reached. In all cases the lifetime of these electrode materials was limited by the slow release of the RuO42− species. 相似文献