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

Abstract

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.

Tropospheric Aqueous-Phase Chemistry: Kinetics, Mechanisms, and Its Coupling to a Changing Gas Phase

“…As shown in Table , the quantum yield of H 2 O 2 photolysis in solution and ice has been shown to be independent of ionic strength, pH, and wavelength. ,, These findings are in contradiction to the wavelength dependency of the quantum yield reported by Kwon et al The quantum yield at T = 298 K observed by Chu et al is in a good agreement with the averaged values reported in Herrmann et al In the aforementioned work, the conditions were such that H 2 O 2 was present in the quasi liquid layer (QLL) so that the aqueous and ice data both follow the same temperature-dependent relationship …”

“…Because the photochemistry of inorganic ligand complexes is already relatively well understood, recent research has focused more on the photochemistry of organic ligand complexes, and specifically on that of organic carboxylate anions. In the case of inorganic systems, new quantum yields at 254 nm have been reported only for iron hydroxide complexes . Available photochemical data for Fe-complexes are summarized in Table .…”

Recent Advances in Anode Electrocatalysts for Direct Formic Acid Fuel Cells – Part I – Fundamentals and Pd Based Catalysts

“…Formic Acid loaded with 3 mg/cm 2 of Palladium. From the CV test carried out for different loading rates of palladium, it was deduced that on lowering the amount of Pd catalyst resulted in efficient and improved cell performance (3 mg/cm 2 ) [317] …”

Electrospray Deposition: A Breakthrough Technique for Proton Exchange Membrane Fuel Cell Catalyst Layer Fabrication

“…The addition of surfactants to create additional porous structures allowing the modification of the layers after deposition has also been tested . There are some successful attempts to expand the use of electrospray deposition to other type of fuel cells by depositing specific catalyst inks, such as Pt/C with polybenzimidazole for high-temperature PEM, Pt/C with polyvinylpyrrolidone for an anion exchange membrane, Pt–Ru/C with Nafion for direct methanol, and palladium black with Nafion for direct formic acid fuel cells …”