Formic Acid Fuel Cells Research Articles

Research Development of Direct Formic Acid Fuel Cells

In recent years,significant developments in direct formic acid fuel cell(DFAFC) have been made. It was reported that the largest energy density of DFAFC with Pd as anodic catalyst is 0. 25 W /cm2,which is close to that of proton exchange membrane fuel cell(PEMFC) with hydrogen as fuel and indicates the excellent development prospects of DFAFC. This review summarized the research development in DFAFC, the mechanism of the oxidation of formic acid,the underlined reason and mechanism of the increase in the performance of Pd based composite catalysts,the main problems of DFAFC and described its development prospects.

Novel Pd Anodes for Direct Formic Acid Fuel Cells

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Influence of a Pore-Former in the Performance of a Direct Formic Acid Fuel Cell

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A Room Temperature Indirect Formic Acid Fuel Cell

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Effects of the Addition of Antimony, Tin, and Lead to Palladium Catalyst Formulations for the Direct Formic Acid Fuel Cell

In an operating direct formic acid fuel cell (DFAFC), the palladium catalyst surface poisons and must be periodically regenerated by oxidative stripping. The objective of this paper is to analyze the effects of antimony, tin, and lead additions to the palladium black catalyst that is used in the DFAFC. We discovered that each adatom strongly promotes formic acid oxidation in an electrochemical cell and reduces the amount of CO poison that develops on the catalyst surface after one hour of oxidation, which suggests a steric effect due to the presence of the adatoms. However, after three hours of oxidation, the poisoning is nearly the same with each of the adatoms, which shows the limitations of the steric effect. We also used X-ray photoelectron spectroscopy to demonstrate a shift in the palladium binding energy due to the presence of the adatoms, which suggests an electronic effect is also present. We conclude that the steric and electronic effects cause a significant enhancement to oxidation in an electr...

A Gold-Nickel Alloy as Anodic Catalyst in a Direct Formic Acid Fuel Cell

Abstract Gold-nickel alloy was synthesized by arc-melted process. The electro-oxidation of formic acid of Au-Ni alloy was investigated at room temperature by cyclic voltammetry and chronoamperometry. The results were compared with those at a polycrystalline gold electrode surface. It is found that Au-Ni alloy is catalytically more active than pure gold according to the comparison of the main peak potential and current density.

Anode Catalysis in Direct Formic Acid Fuel Cells

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Novel Pd Anodes for Direct Formic Acid Fuel Cells

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PdBi/C and PtPb/C Bimetallic Catalysts for Direct Formic Acid Fuel Cells

An efficient methodology for comparing anode catalysts for direct formic acid fuel cells (DFAFCs) by employing a multi-anode, liquid-fed fuel cell is presented. PdBi/C bimetallic catalysts synthesized by co-depositing Pd and Bi on Vulcan XC-72 carbon black, as well as PtPb/C bimetallic catalysts synthesized by depositing Pb on a Pt/C catalyst, were systematically studied in a multi-anode DFAFC. The PdBi/C catalysts showed higher stability than a commercial Pd/C catalyst, while addition of Pb significantly improved activity of the Pt/C catalyst. A surface-modified PtPb/C catalyst that exceeds the performance of Pd/C is reported.

A Facile Preparation of Hollow Palladium Nanosphere Catalysts for Direct Formic Acid Fuel Cell

A facile and low-cost preparation of a polypyrrole-modified Vulcan XC-72 carbon-supported Pd/PPy−XC-72 hollow nanosphere catalyst was introduced in this paper. To increase the stability and utilization ratio of the catalyst, a two-step strategy was employed, which included the synthesis of a polypyrrole−carbon composite and the preparation of a hollow nanosphere catalyst. Co nanoparticles as sacrificial templates were deposited on the prepared polypyrrole−carbon composites by chemical reduction, and then Pd hollow nanospheres formed through the surface replacement reaction between the surface of Co nanoparticles and PdCl2 at room temperature. The novel Pd/PPy−XC-72 hollow nanosphere catalyst was 30−40 nm in diameter and 3−4 nm in shell thickness. FT-IR and TGA characterizations confirmed the existence and content of polypyrrole in the catalysts. The catalysts with 40 and 20% Pd showed a very high electrochemically active surface area and significant increase in electrocatalytic activity toward formic acid oxidation, which make them the preferable catalysts for direct formic acid fuel cells.

Effect of Organic Impurities on the Performance of Direct Formic Acid Fuel Cells

Palladium (Pd) anode catalyst shows high electrocatalytic oxidation activity under ambient conditions for direct formic acid fuel cell (DFAFC) operation. However, the highly active Pd is susceptible to significant catalyst poisoning by impurities present in the fuel. In this study, the effect of methyl formate, methanol, and acetic acid impurities on DFAFC performance was investigated. These organic impurities will increase the poisoning rate of the highly active Pd catalyst, resulting in a reduction of fuel cell power output. The impact on performance of various levels of impurities is reported.

A Stable and Cost‐Effective Anode Catalyst Structure for Formic Acid Fuel Cells

Cheap and stable: A PtBi catalyst was fabricated in three consecutive electrochemical steps (see picture): electrochemical oxidation of carbon paper to form an adequate catalyst support (1), Pt electrodeposition (2), and underpotential deposition of Bi onto the as-prepared Pt (3). This process resulted in a well-dispersed and thin catalyst layer as well as a significantly enhanced power performance with a Pt loading of only 0.5 mg cm−2.

A Stable and Cost‐Effective Anode Catalyst Structure for Formic Acid Fuel Cells

Billig und beständig: Ein PtBi-Katalysator wurde in drei Schritten durch elektrochemische Oxidation von Kohlenstoffpapier zur Bildung eines Katalysatorträgers (1), elektrochemische Abscheidung von Platin (2) und Unterpotentialabscheidung von Bismut auf dem Pt-modifizierten Material (3) erhalten (siehe Bild). Diese Vorgehensweise ergab eine gleichmäßige, dünne Katalysatorschicht mit deutlich besserer Leistungsfähigkeit bei nur 0.5 mg cm−2 Pt.

Effect of the Anode Structure on the Performance of Direct Formic Acid Fuel Cells

Single MEA direct formic acid fuel cells were assembled using various anode diffusion electrodes and various Nafion/Pd black ratios for the catalyst layers. Power densities above 100 mW cm-2 were obtained at room temperature with 10 M formic acid fed to the anode and O2 at atmospheric pressure fed to the cathode. The best results were obtained when untreated carbon cloth was used as the anode diffusion layer and with a catalyst layer composed of equal volumes of Nafion and Pd black electrocatalyst. We have also observed increased performance of the MEA when the flow of formic acid is drastically reduced, probably due to a better evacuation of CO2; the gas produced at the anode due to the oxidation of formic acid.

Effect of the Anode Structure on the Performance of Direct Formic Acid Fuel Cell

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Electrocatalytic Performance of Carbon Supported Au-Ir Catalyst as Cathodic Catalyst in Direct Formic Acid Fuel Cell

Electrocatalytic Performance of Carbon Supported Au-Ir Catalyst as Cathodic Catalyst in Direct Formic Acid Fuel Cell

Efficient Anodes for Direct Methanol and Formic Acid Fuel Cells: the Synergy Between Catalyst and Three-Dimensional Support

The synergy between three-dimensional support (graphite felt uncompressed thickness , GF) and catalyst preparation method afforded a four times reduction of the catalyst load in direct methanol fuel cell (DMFC) anodes while improving the power density compared to both the catalyst-coated membrane (CCM) and catalyst-coated diffusion layer designs (CCDL). In DMFC experiments the anode generated a maximum power density of at compared to 703 and obtained with CCM and CCDL, respectively, both with load. In direct formic acid fuel cell experiments at and concentration, the maximum power density using the anode reached , compared to with CCM. A micellar solution composed of the nonionic surfactant Triton X-102 and an aqueous phase containing and was utilized for the galvanostatic electrodeposition of nanoparticles ( crystallite size), assuring excellent catalyst penetration throughout the GF thickness as demonstrated by surface analytical techniques. The type of micellar media employed for electrodeposition had an impact on the crystallographic features of the catalyst and conversely on the electrocatalytic activity. The highest activity was observed for with the largest fraction of Pt [1,1,1] and [3,1,1] crystal facets and bimetallic surface structure as opposed to alloy. The present work opened up a venue for “designing” the catalytic surface and exploiting the catalyst/three-dimensional support interaction for direct liquid fuel cell anodes.

Electrochemically Modified Palladium Black as the Anode Catalyst for the Direct Formic Acid Fuel Cell

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The Mechanism of Direct Formic Acid Fuel Cell Using Pd, Pt and Pt-Ru

The electro-oxidation of formic acid, 2-propanol and methanol on Pd black, Pd/C, Pt-Ru/C and Pt/C has been investigated to clear the reaction mechanism. It was suggested that the formic acid is dehydrogenated on Pd surface and the hydrogen is occluded in the Pd lattice. Thus obtained hydrogen acts like pure hydrogen supplied from the outside and the cell performance of the direct formic acid fuel cell showed as high as that of a hydrogen-oxygen fuel cell. 2-propanol did not show such dehydrogenation reaction on Pd catalyst. Platinum and Pt-Ru accelerated the oxidation of C-OH of 2-propanol and methanol.Slow scan voltammogram (SSV) and chronoamperometry measurements showed that the activity of formic acid oxidation increased in the following order: Pd black > Pd 30wt.%/C > Pt50wt.%/C > 27wt.%Pt-13wt.%Ru/C. A large oxidation current for formic acid was found at a low overpotential on the palladium electrocatalysts. These results indicate that formic acid is mainly oxidized through a dehydrogenation reaction. For the oxidation of 2-propanol and methanol, palladium was not effective, and 27wt.%Pt-13wt.%Ru/C showed the best oxidation activity.

Controllable Synthesis of Pd Nanocatalysts for Direct Formic Acid Fuel Cell (DFAFC) Application: From Pd Hollow Nanospheres to Pd Nanoparticles

The controllable synthesis of nanosized carbon-supported Pd catalysts through a surface replacement reaction (SRR) method is reported in this paper. Depending on the synthesis conditions the Pd can be formed on Co nanoparticles surface in hollow nanospheres or nanoparticles structures. Citrate anion acts as a stabilizer for the nanostructures, and protonation of the third carboxyl anion and hence the nanostructure and size of the resulting catalysts are controlled via the pH of the synthesis solution. Pd hollow nanospheres, containing smaller Pd nanoparticles, supported on carbon are formed under the condition of pH 9 reaction solution. Meanwhile, highly dispersed carbon-supported Pd nanoparticles can be formed with higher pH (pH ≥ 10). All catalysts prepared through the SRR method show enhanced activities for the HCOOH electro-oxidation reaction compared to catalysts reduced by NaBH4.