Fuel Cell Demonstrator characteristics

Figure 7-15. K/7 characteristic of micro fuel cell demonstrator, three cells 0.18 cm serial interconnected, 25°C, 50% RH...

Figure 7-16. Vll characteristic of micro fuel cell demonstrator with segmented MEA in comparison with an unsegmented MEA...

DaimlerChrysler developed a methanol processor for the NeCar 3 experimental vehicle. This was demonstrated in September 1997 as the world s first methanol-fuelled fuel cell car. It was used in conjunction with a Ballard 50-kW fuel cell stack. Characteristics of... 

Li, Q., R. He, J. O. Jensen and N. J. Bjerrum. PBI-based polymer membranes for high temperature fuel cells - preparation, characteristics and fuel cell demonstration. Fuel Cells 4(3) 147-159, 2004. 

The focus of the utility demonstrations and FCE s fuel cell development program is the commercialization of 300 kilowatt, 1.5 megawatt, and 3 megawatt MCFC plants. Characteristics of the FCE 3 megawatt internal reforming commercial MCFC plant are as follows (17) ... 

Operators of the Tokyo demonstration plant have concluded that phosphoric acid fuel cell technology is ready for commercialization. The project demonstrated that (I) fuel cells can be sited in urban areas which are regulated by strict environmental constraints (2) performance and operational characteristics were very close to design goals and (3) utility personnel can efficiently operate and maintain fuel cell plant equipment with minimal additional training. As a consequence of the demonstration plant success, a new 11 -MW power plant will be developed and marketed. A comparison of the new 1 C 23 Unit with the 4,5 MW demonstration plant is given in Table 4. 

TABLE 4. COMPARISON OF CHARACTERISTICS-DEMONSTRATION AND COMMERCIAL FUEL CELL POWER PLANTS... 

Electronic interaction and synergistic effects between catalysts and the support material have been investigated in the context of fuel-cell electrocatalysts. Electron spin resonance (ESR) has been used to demonstrate the electron donation by Pt to carbon [11] support. This has been further supported by XPS studies [12], which show that the metal acts as an electron donor to the support, their interaction depending on their respective Eermi levels. Bogotsky and Snudkin [13] have shown that the characteristics of the electrical double layer formed between the microdeposit (Pt) and the support depends to a certain extent on the difference in the work function of Pt (5.4 eV) and carbon support (pyrolytic support 4.7 eV), thereby resulting in an increase of the electron density of Pt. However, the rise in the electron density can be significant only when the particle size of the microdeposit is comparable to the thickness of the double layer. 

In a fiirther series of experiments, phosphotungstic acid (PWA) was impregnated onto silica particles and the resulting material was loaded in the recast Nafion. As is well known, heteropolyacids (HPAs) have demonstrated suitable characteristics to be used as proton conductive materials in fuel cells [4-6]. Due to dissolution phenomena in water, however, previous experiments using solid heteropolyacid did not result in stable fuel cell performance [5]. To overcome this problem, resulting in a short lifetime of the fuel cell, experiments of blocking the HPA in a host material were carried out [7-9]. Thus, in this work the phosphotungstic acid-modified membrane was compared, in terms of performance, with the bare silica-recast Nafion membrane in direct methanol fuel cell at 145°C. 

The potential ability of fuel cells (FCs) to become an alternative to the conventional energy sources has been well demonstrated. However, high cost, durability, high system complexity and lack of fuel inlrastmcture are drawbaks that still keep in standby their large-scale commercialization [1, 2]. Table 1 summarizes some technical characteristics of the main... 

The main preparation methods for H2 technical electrodes for low temperature fuel cells have been examined. It has been demonstrated that the electrochemical behavior of the electrodes depends on their fabrication, thus affecting the fuel cell operation. The preparation of the catalyst of the active layer also influences its physical properties and electrochemical performance. Different electrochemical approaches to study HOR on model, as a first approximation, and technical electrodes, are exhaustively analyzed and their kinetic parameters are discussed to evaluate their performance and system modelling. The existence of a gap between the knowledge obtained from studies on model electrodes and technical electrodes is emphasized. To optimize the performance of practical fuel cell electrodes, the preparation of high surface area catalysts with the same characteristics as those shown at the atomic level then seems necessary. In this sense, mechanistic studies are fimdamental to... 

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