Comparative study of three different catalyst coating methods for direct methanol fuel cells

Choi, Hyung Joo; Kim, Jinsoo; Kwon, Yongchai; Han, Jonghee

doi:10.1016/j.jpowsour.2009.06.106

Cited by 16 publications

(9 citation statements)

References 24 publications

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“…Catalyst ink-based methods including decal transfer, [ 10 ] hand painting, [ 11 , 12 ] spray deposition (e.g., air-brush, [13][14][15] ultrasonicspray, [ 16 ] electro-spray), [ 17 ] and screen printing [ 18 ] processes are commonly used. Moreover, electrodeposition, [ 19 ] sputter deposition, [ 20 ] and dual ion-beam assisted deposition [ 21 ] (particularly for catalyst loadings down to 0.04 mg/cm 2 ) have also been studied.…”

Section: Introductionmentioning

confidence: 99%

The Effects of Catalyst Layer Deposition Methodology on Electrode Performance

Jhong

Brushett

Kenis

2013

Advanced Energy Materials

198

191

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The catalyst layer of the cathode is arguably the most critical component of low‐temperature fuel cells and carbon dioxide (CO2) electrolysis cells because their performance is typically limited by slow oxygen (O2) and CO2 reduction kinetics. While significant efforts have focused on developing cathode catalysts with improved activity and stability, fewer efforts have focused on engineering the catalyst layer structure to maximize catalyst utilization and overall electrode and system performance. Here, we study the performance of cathodes for O2 reduction and CO2 reduction as a function of three common catalyst layer preparation methods: hand‐painting, air‐brushing, and screen‐printing. We employed ex‐situ X‐ray micro‐computed tomography (MicroCT) to visualize the catalyst layer structure and established data processing procedures to quantify catalyst uniformity. By coupling structural analysis with in‐situ electrochemical characterization, we directly correlate variation in catalyst layer morphology to electrode performance. MicroCT and SEM analyses indicate that, as expected, more uniform catalyst distribution and less particle agglomeration, lead to better performance. Most importantly, the analyses reported here allow for the observed differences over a large geometric volume as a function of preparation methods to be quantified and explained for the first time. Depositing catalyst layers via a fully‐automated air‐brushing method led to a 56% improvement in fuel cell performance and a significant reduction in electrode‐to‐electrode variability. Furthermore, air‐brushing catalyst layers for CO2 reduction led to a 3‐fold increase in partial CO current density and enhanced product selectivity (94% CO) at similar cathode potential but a 10‐fold decrease in catalyst loading as compared to previous reports.

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Section: Introductionmentioning

confidence: 99%

The Effects of Catalyst Layer Deposition Methodology on Electrode Performance

Jhong

Brushett

Kenis

2013

Advanced Energy Materials

198

191

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“…The loading amounts of the Pd and Pt catalysts were 3 and 4 mg/cm 2 , respectively. As for the loading procedure of catalysts, we used the same sequence that was reported elsewhere [29].…”

Section: Methodsmentioning

confidence: 99%

Evaluation of direct formic acid fuel cells with catalyst layers coated by electrospray

Kwon

Baek

Kwon

et al. 2010

Korean J. Chem. Eng.

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We investigated cell performance and performed phenomenological analyses of direct formic acid fuel cells (DFAFCs) incorporating anode (palladium) and cathode (platinum) catalysts prepared using a new electrospray coating technique. To optimize the design of the DFAFC, we examined the cell performance by the Pd catalyst loading and formic acid feed rate. Of Pd catalyst loaded samples, 3 mg/cm 2 sample showed the highest electrical performance with formic acid feed rate of 5 ml/min. This behavior was caused by discrepancies in the mass transfer limitation. When the feed rate was greater than 10 mL/min, however, the 7 mg/cm 2 sample provided the highest electrical performance, which was attributed to enhanced electrooxidation reactions. For comparison of the effect of the catalyst coating method on the cell performance of DFAFC, polarization curves of the DFAFC incorporating catalysts prepared using a conventional airspray coating method were also measured. As a result of the comparison, the electrospray coatingused DFAFC showed better cell performance. Based on these results, the cell performance of the DFAFCs was optimized when the catalysts using the electrospray catalyst coating were employed, the amount of Pd loaded on the anode electrode was 3 mg/cm 2 (Pd thickness: ~6 µm), and the formic acid feed rate was 10 mL/min.

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“…Pd + H 2 O → PdOH + H + + e − → PdO + 2H + + 2e − (forward scan for anode catalyst) (6) PdO + 2H + → Pd 2+ + H 2 O (backward scan for anode catalyst) (7)…”

Section: 28mentioning

confidence: 99%

“…Polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) that utilize hydrogen and methanol as fuels have been continuously tested as the candidates for meeting the requirements. [4][5][6] However, in spite of such efforts, in PEMFCs, a high cost of hydrogen container and a low gasphase energy density have prevented it from becoming a baseline fuel cell system, while in DMFCs, a slow rate of electrochemical methanol oxidation, a high fuel crossover rate, and an inherent toxicity have made its use hesitate.…”

Section: Introductionmentioning

confidence: 99%

Performance Enhancement by Adaptation of Long Term Chronoamperometry in Direct Formic Acid Fuel Cell using Palladium Anode Catalyst

Kwon

Baik

Han³

et al. 2012

Bulletin of the Korean Chemical Society

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In the present study, we suggest a new way to reactivate performance of direct formic acid fuel cell (DFAFC) and explain its mechanism by employing electrochemical analyses like chronoamperometry (CA) and cyclic voltammogram (CV). For the evaluation of DFAFC perforamce, palladium (Pd) and platinum (Pt) are used as anode and cathode catalysts, respectively, and are applied to a Nafion membrane by catalyst-coated membrane spraying. After long DFAFC operation performed at 0.2 and 0.4 V and then CV test, DFAFC performance is better than its initial performance. It is attributed to dissolution of anode Pd into Pd 2+. By characterizations like TEM, Z-potential, CV and electrochemical impedance spectroscopy, it is evaluated that such dissolved Pd 2+ ions lead to (1) increase in the electrochemically active surface by reduction in Pd particle size and its improved redistribution and (2) increment in the total oxidation charge by fast reaction rate of the Pd dissolution reaction.

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Comparative study of three different catalyst coating methods for direct methanol fuel cells

Cited by 16 publications

References 24 publications

The Effects of Catalyst Layer Deposition Methodology on Electrode Performance

The Effects of Catalyst Layer Deposition Methodology on Electrode Performance

Evaluation of direct formic acid fuel cells with catalyst layers coated by electrospray

Performance Enhancement by Adaptation of Long Term Chronoamperometry in Direct Formic Acid Fuel Cell using Palladium Anode Catalyst

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