Electrochemical impedance characteristics and electroreduction of oxygen at tungsten carbide derived micromesoporous carbon electrodes

Härk, Eneli; Nerut, Jaak; Vaarmets, Kersti; Tallo, Indrek; Kurig, Heisi; Eskusson, Jaanus; Kontturi, Kyösti; Lust, Enn

doi:10.1016/j.jelechem.2012.09.039

Cited by 36 publications

(85 citation statements)

References 33 publications

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“…C(Mo 2 C) has larger pores compared with C(WC). After the modification of carbon support with electrochemically active metal nanoparticles the surface area was reduced (20,21). Electrochemical characterization CV and RDE data show that high cathodic O 2 electroreduction current densities have been achieved for the Pt-C(Mo 2 C) and Pt-C(WC) GCDE electrode studied (Fig.…”

Section: Table I Results Of Sorption Measurements For C(mo 2 C) and mentioning

confidence: 97%

“…The particle size of catalyst support is about 1-7 m. Modification of catalyst support with nanoparticles of platinum and Pt-Ru alloy did not change noticeably the particle size and the structure of powder. X-ray diffraction (XRD) technique and EDX analysis were used to demonstrate the formation of Pt-Ru alloy with the atomic fraction 0.5 of Ru in the alloy (20,21).…”

Section: Resultsmentioning

confidence: 99%

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Impact of the Various Catalysts (Pt, Pt-Ru) Deposited onto Carbon Support to the Slow Oxygen Reduction Reaction Kinetics

et al. 2013

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Micro-and mesoporous carbide derived carbons synthesized from molybdenum and tungsten carbide were used as supports for platinum and Pt-Ru alloy catalysts. The scanning electron microscopy, X-ray diffraction, Raman spectroscopy, high resolution transmission electron microscopy and low temperature N 2 adsorption experiments were carried out to characterize the structure of prepared materials. The kinetics of oxygen reduction was studied using cyclic voltammetry and rotating disc electrode in 0.5 M H 2 SO 4 solution. The synthesized materials exhibited high specific surface area. The platinum or Pt-Ru alloy deposited onto the surface of carbon in the form of nanoparticles or agglomerates of nanoparticles. All catalysts showed high activity towards oxygen reduction.

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Section: Table I Results Of Sorption Measurements For C(mo 2 C) and mentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

Impact of the Various Catalysts (Pt, Pt-Ru) Deposited onto Carbon Support to the Slow Oxygen Reduction Reaction Kinetics

et al. 2013

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“…The higher catalytic activity of C(Mo 2 C) based electrocatalysts, compared with Vulcan based electrodes, is mainly caused by more amorphous, defective (20) and more developed hierarchical mesoporous and microporous structure of the carbon support used (15)(16)(17)(18)(21)(22)(23)(36)(37)(38).…”

Section: Catalytic Activity Test Using Rde and CV Methodsmentioning

confidence: 99%

“…Microporous-mesoporous (MMP) carbon powder (C(Mo 2 C)) was synthesized at the fixed temperature (750 °C) from molybdenum carbide using high-temperature chlorination technique and then cleaned with hydrogen (800° C, 4h) and argon (15)(16)(17)(18)(20)(21)(22)(23). The carbon powder prepared has high Brunauer-Emmett-Teller surface area (S BET ) of 2070 m 2 g -1 and microporous-mesoporous hierarchical structure.…”

Section: Synthesis Of Catalyst For Oxygen Reduction Reactionmentioning

confidence: 99%

Oxygen Electrocatalysis on High-Surface Area Non-Pt Metal Modified Carbon Catalysts

et al. 2015

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Series of carbon supported non-noble d-metal Fe or d-metalnitrogen (Fe-N-or Co-N-) nanocluster activated electrocatalysts have been synthesized by sodium borohydride reduction method. Synthesized d-metal-nitrogen carbon catalysts were studied using X-ray diffraction, scanning electron microscopy, time of flight secondary ion mass-spectrometry and Raman spectroscopy methods. The electrochemical parameters of synthesized catalysts were investigated in alkaline media using cyclic voltammetry and rotating disk electrode methods. The high catalytic activity toward oxygen electroreduction reaction was demonstrated and found to be increasing in the following order: Fe-Vulcan; Co-N-Vulcan; Co-N-C(Mo 2 C); Fe-N-C(Mo 2 C). The possibility to replace the Pt metal catalyst with non-noble metal-nitrogen carbon electrocatalyst has been discussed.

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“…Under start-stop conditions, the corrosion of carbon support for conventional cathode catalysts is a critical problem for PEMFC durability in automotive applications [16][17][18][19][23][24][25]. Therefore, different carbon supports [17][18][19][23][24][25][26][27][28][29][30][31] have been tested during long-term catalyst optimization studies [16][17][18][19][32][33][34][35][36]. Influence of structural parameters of PEMFC electrodes like the particle size, interparticle distance, and metal (Pt, Pt-metal, or non-Pt-metal) loading has been systematically tested and summarized in many papers [14][15][16][17][18][19][21][22][23][24][25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Enhanced stability of symmetrical polymer electrolyte membrane fuel cell single cells based on novel hierarchical microporous-mesoporous carbon supports

Sepp

Vaarmets

Nerut

et al. 2016

J Solid State Electrochem

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Fuel cell electrodes were prepared from Pt nanocluster activated hierarchical microporous-mesoporous carbon powders. The carbon supports were synthesized from molybdenum carbide applying the high-temperature chlorination method. Six different synthesis temperatures within the range from 600 to 1000°C were used for preparation of carbon supports. Thermogravimetric analysis, X-ray diffraction, low-temperature nitrogen sorption, and high-resolution scanning electron microscopy methods were used to characterize the structure of the electrode materials and symmetrical membrane electrode assemblies (MEAs). The MEAs prepared were used to conduct the proton exchange membrane fuel cell (PEMFC)single-cell measurements. The polarization and power density curves for single cells were calculated to evaluate the activity of the catalyst materials synthesized. The electrochemically active surface area (from 2.4 to 11.9 m 2 g −1) was obtained in order to estimate the contact surface areas of platinum and Nafion® electrolyte. The values of the electrolyte resistance, polarization resistance, and cell degradation rate were calculated from electrochemical impedance spectroscopy data. The carbon materials synthesized within temperature range from 600 to 850°C were found to be the most suitable supports for PEMFCs, having higher maximum power density values and better stability (cell potential degradation 240 μV h −1) than commercial carbonbased (Vulcan XC72; 670 μV h −1) single cells.

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Electrochemical impedance characteristics and electroreduction of oxygen at tungsten carbide derived micromesoporous carbon electrodes

Cited by 36 publications

References 33 publications

Impact of the Various Catalysts (Pt, Pt-Ru) Deposited onto Carbon Support to the Slow Oxygen Reduction Reaction Kinetics

Impact of the Various Catalysts (Pt, Pt-Ru) Deposited onto Carbon Support to the Slow Oxygen Reduction Reaction Kinetics

Oxygen Electrocatalysis on High-Surface Area Non-Pt Metal Modified Carbon Catalysts

Enhanced stability of symmetrical polymer electrolyte membrane fuel cell single cells based on novel hierarchical microporous-mesoporous carbon supports

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