 |
|
|
|
|
 |
|
|||
 |
 |
 |
|
|
 |
|
|||
 |
|
|||
 |
 |
|
||
 |
|
|||
 |
|
|||
 |
|
|||
 |
 |
|
||
 |
|
|||
 |
|
|||
 |
 |
|
||
 |
|
|||
ezstat l arraystat l single cell fuel cell l array fuel cell l heated vacuum table
The NuVant Screening Philosophy
The Arraystat screening system is based on the philosophy that the only reliable way to screen a fuel cell component is in an actual fuel cell environment. NuVant’s patented technology uses an array membrane electrode assembly. The counter electrode is a large area, standard fuel cell electrode while the array side consists of a library of 25 discs. Each disk consists of a gas diffusion layer (GDL) disc that is catalyzed by the end user's method. The catalyzed GDLs are positioned on the polymer electrolyte membrane by an array gasket and then hot pressed onto the membrane with the counter electrode on the opposite face. Alternatively, the membrane can be catalyzed and clean diffusion layers can be interfaced. The array MEA is then housed in a patented array fuel cell through which fuel and oxidant are delivered. An advanced high power array potentiostat (Arraystat) is used to obtain 25 polarization curves in parallel, or any number of electrodes can be separately studied with other electrodes at open circuit.
Statistically better data are obtained with an array fuel cell than with many individual test stands, because the common counter electrode eliminates an important source of random error. If hydrogen is delivered to the counter electrode, that electrode can serve as a dynamic hydrogen reference electrode. Alternatively, the array can be run in the standard hydrogen/air or methanol/air modes. For low stoic ratio screening, NuVant has developed a row switching mechanism that ensures uniform stoic ratios down a column of discs as polarization curves are obtained row by row.
Using conventional equipment, the simultaneous acquisition of 25 polarization curves would require 25 test stations with 50 mass flow controllers and over a hundred temperature control units. In addition, substantial human resources would be required. The Arraystat requires only one pair of mass flow controllers and a single operator to run the equivalent of 25 single cell test stations. NuVant can fabricate larger arrays upon request.
NuVant provides training in the preparation of high performance MEAs as well as in the use of the Arraystat instrumentation.
Literature references
1. E. S. Smotkin; J. Jiang; A. Nayar; R. Liu, “High-throughput screening of fuel cell electrocatalysts” Applied Surface Science, 252; 2573-2579, (2006)
2. R. Liu; E. S. Smotkin, "Array membrane electrode assemblies for high throughput screening of direct methanol fuel cells anode catalysts", Journal of Electroanalytical Chemistry 525 (2002) 49-55
3. E. S. Smotkin, "High throughput screening device for combinatorial chemistry" US Patent 6692856, Feb. 17, 2004
4. R. R. Diaz-Morales; R. Liu; E. Fachini; G. Chen; C. U. Segre; A. Martinez; C. C. Cabrera; E. S. Smotkin; J. Electrochem. Soc, 151, A1314 (2004)
5. E. S. Smotkin & R. R. Diaz-Morales, "New Electrocatalysts by Combinatorial Methods" Ann. Rev. Mater. Res, 2003, 33: 557-79
HOME l ABOUT US l PRODUCTS l ALLIANCE l TEAM l DIRECTORS l INVESTOR l CONTACT US
Copyright © 2007 NuVant Systems Inc. - Design by: Navarro's Specialty