Fuel cell test

Fuel-cell tests offer the ultimate verification of the usefulness of an electrocatalyst by determining its long-term stability under real operating conditions. They were performed on single cells using electrodes of 50 cm and an anode catalyst loading of 0.2 mg 

XANES data show that Pt in the PtRu2o has 0.345 5d vacancy/atom. The back-bonding from the Pt to CO may decrease in this case, the likely reason for this catalyst s good CO tolerance. The weaker CO bonding on PtRu2o than on Pt or the Pt-Ru alloy was confinned by CO striping voltammetry. These data show that the electronic effect in Pt-Ru electrocatalysts may be more important than previously assumed. 

Bewick et al. identified CO as the species that acts as a catalytic poison and inhibits further oxidation of methanol on Pt electrodes. The reactive intermediate is a formate species, HCOO that generates asynunetric COO vibration around 1300 cm, leading to an increase in the methanol oxidation current after CO oxidation. Recently, water molecules were detected adsorbed on the Ru sites on Ru and Pt-Ru (but not on Pt) catalysts, and were assigned as the oxy gen donor to the methanol adsorbates that promote methanol oxidation. This was considered as directly supporting the bi-functional mechanism of Pt-Ru catalysts for the methanol-oxidation reaction.  

Methanol oxidation proceeds with the progressive dehydrogenation of the organic molecule on the anode surface, viz. 

Pt has the highest adsorption of methanol on its surface, but its catalytic properties are low due to the formation of poison species (most notably CO) that can be oxidized only after the Pt is covered with OH. Platinum-based bimetallic electrocatalysts, such as Pt-Ru alloys and Ru-decorated Pt materials, are the most active ones. The bi-functional mechanism is to a large extent operative in these catalysts. Most commercial Pt-Ru catalysts are based on 1 1 Pt-Ru alloy. While the alloys typically show enhanced activity in comparison with pure Pt, there is significant Pt loading in the bulk of the alloy in which catalysis does not proceed because the sites are inaccessible for methanol adsorption hence, the need for reducing the Pt content. 

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Our fuel cell test fixture was made from a commercially available membrane filter holder. We spot-welded electrode studs to the two halves of the fixture case, one for the hydrogen side and one for the oxygen (air) side. 

Following our visit to the Schatz Lab, we went back to the drawing board and added the O ring seals to the case. In March 1993, the cases were machined to accept the O rings and we were ready to try again. Another dip in the water container with 200 KPa (30 psig) hydrogen pressure showed that the leaks in the fuel cell test fixture had been stopped. 

GM conducted its first fuel cell testing in 1964 and in 1968 GM produced the auto industry s first operational fuel cell powered vehicle. The first drivable fuel cell concept car was based on the GM Opel Zafira minivan in 1998. The HydroGenl fuel cell vehicle based on the Opel Zafira compact van served as the pace car for the men s and women s marathons at the Summer Olympics in Sydney, Australia. 

Toyota and Honda have been experimenting with both methanol and metal-hydride storage of hydrogen. Honda has built several test cars, in 1999 a Honda FCX-V1 (metal-hydride hydrogen) and FCX-V2 (methanol) were tested at a track in Japan. The Ballard powered version-1 was ready, but proved to be a little sluggish and noisy. The other car suffered from a noisy fuel cell. Both Honda fuel cell test cars were built on the chassis of the discontinued EV Plus battery electric. Honda used a different and more aerodynamic body. 

The fuel cell test facility of FCPOINT, where all this activity is performed, allows characterisation of the electrical and environmental performance of Polymer Electrolyte Fuel Cell... 

PEFC) stacks, components and entire systems, in off-grid, and grid-connected configurations, with a capacity of up to 100 kW electrical power output. The facility consists of an automated and computerised fuel cell test station, gas analysers, a multi-axial vibration system which is housed in a walk-in environmental chamber (for controlling temperatures, humidity, shocks and vibrations) and ancillary equipment. The data obtained are complementary to and validate fuel cell simulations and models with reference to operation modes, components and system characteristics 1 ... 

IdaTech LLC (formerly Northwest Power Systems), of Bend, Oregon, an Idacorp subsidiary, delivered the first of 110 planned fuel cell systems to the Bonneville Power Administration (BPA), Portland, Oregon in June 2000. The BPA program is part of a fuel cell test and development phase intended to commercialize fuel cell systems for home and small commercial applications by 2003. 

A similar study was performed by Jian-hua et al. [137], who used (NH4)2S04 as the pore former due to its high solubility in water. After fuel cell testing was performed, it was observed that the pore former improved the performance of the cell at higher current densities (>0.9 A cm" ), indicating that control of the pore distribution in the MPL and DL was critical to enhancing the efficiency of the fuel cell system. 

Fuel cell testing showed that this WTR improved the fuel cell performance significantly for operation at a temperature of 40°C (with dry gases). Unfortunately, the fuel cell was not tested at higher temperatures. Another issue is that it is unclear how the fuel cell was modified in order to be able to have this extra layer (on each side) because it is out of the active area and may be affected by the use of seals. In addition, these MPLs represent several additional manufacturing steps that have to be added for each MEA produced. 

Mao et al. [174] recently presented research in which Nafion ionomer particles were used as hyperdispersant agents in the MPL of a cathode DL. It was shown that this ionomer helps to decrease the particle size of the PTFE in the MPL. Thus, increasing the Nafion particle content gradually decreased the PTFE size and decreased the hydrophobicity in the layer. In fuel cell testing, an MPL having 1 wt% ionomer showed the best performance it improved the gas permeability and electronic conductivity. 

As briefly mentioned in Section 4.3.S.2, Atiyeh et al. [152] performed water balance measurements and calculations to determine the effect of using DLs with MPLs (on either or both cathode and anode sides). In their fuel cell test station, water collection systems were added in order to be able to collect and measure accurately the water leaving both anode and cathode sides of the fuel cell. Based on the operating conditions (e.g., pressures, temperatures, relative humidities, etc.) and the total amount of water accumulated at the outlets of the test station, water balance calculations were performed fo defermine the net water drag coefficient. Janssen and Overvelde [171] used this method to observe how different operating conditions and fuel cell maferials affected... 

Borup et al. [254,255,258] have studied the corrosion of DLs. They aged different types of hydrophobic treated DLs for around 1,000 hours in deionized water at 80°C. After these aging tests, the samples were fuel cell tested at different relative humidities. It was observed that the DLs that were aged behaved like hydrophilic DLs they showed the best performance under dry conditions and the worst under high-humidity conditions due to flooding. On the other hand, hydrophobic DL materials that were not aged showed the lowest performance during dry conditions and the best... 

Through the use of x-ray-induced photoelectron spectroscopy (XPS), Schulze et al. [259] were able to demonstrate that the PTFE particles, which are coated on the diffusion layers, decomposed after fuel cell testing for more than 1,600 hours. This resulted in a change of the hydrophobic properties of the DL. Unfortunately, the mechanism behind the decomposition of PTFE was not explained. 

Figure 28. XANES for an unsupported PtRu black catalyst (a and c) as prepared and (b and d) following fuel cell testing as a methanol oxidation catalyst and reference compounds at (a and b) the Pt L3 edge and (c and d) the Ru K edged (Reproduced with permission from ref 102. Copyright 2001 American Chemical Society.)...

Figure 6, Flow sheet of the 12,5 kW United Technologies fuel cell tested by...

The PSO-Elkraft Project established fuel cell testing facilities for the Danish-developed Solid Oxide Fuel Cells (DK-SOFC). Some lifetime factors have been identified and a new generation of cells have been developed with improved lifetime performance. 

In 1999, the Ministry of Research, in association with the Ministry of Industry, created the Fuel Cell Technological Research Network (PACo network) to contribute to French energy policy for the development of new energy sources. The purposes of the network were to foster creativity and innovation needed for the commercial development of fuel cells and to encourage public-private partnerships and facilitate interdisciplinary cooperation. In July 2000, the government launched CNRT (Centre National de Recherche Tech nolog ique) in Belfort-Montbeliard, involving the construction of a fuel cell test platform dedicated to transport applications. The fiiel cell test capacities have demonstrated power up to 200 kW. 

Fuel Cell Test Evaluation Centre (FCTec). 

Fuel Cell Test Evaluation Centre (FCTec) http //www.dodfueiceii.com/test evai/... 

Figure 1. Schematic layout of the NIST BT-2 neutron imaging facility, including the main neutron optic components as well as the location of the fuel cell test and control infrastructure.

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