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The power to control dispersion, composition and microstructure properties dependably at high volume
 Fuel cell and MEA developers demand electrocatalysts designed and optimized for their precise operating conditions, service life and cost targets. Given challenging commercialization targets, there is no room to compromise on performance. Reproducibility and tight quality control is key – developers need to know that the same electrocatalysts they buy in gram quantities for R&D will be available for their high volume applications.
The common method to produce the carbon-supported platinum or platinum-alloy electrocatalysts currently used in polymer electrolyte membrane (PEM) fuel cells is by precipitating or impregnating platinum and alloying elements using chemical reduction techniques in an aqueous slurry of carbon black support. The complexity of the multistep process makes it very difficult to consistently reproduce the electrocatalyst. In addition, development cycles are long and the performance of the electrocatalyst is frequently not satisfactory for commercial applications.
Cabot has applied its thorough understanding of electrocatalyst materials design, development and production to develop a highly reproducible, low cost, high volume electrocatalyst powder manufacturing process based on spray conversion technology, a unique manufacturing and development platform.
 Using this platform, Cabot can achieve unparalleled control over dispersion, composition and microstructure leading to unrivaled electrochemical performance. In the spray conversion process, feedstock comprising a liquid containing dissolved non-volatile precursors and suspended solids are atomized to form droplets and the droplets are heated to form powders. Through control over the temperature and time history during the processing of the droplets, the characteristics of the final particles such as microstructure, morphology, crystallinity, catalyst dispersion and porosity can be precisely controlled.
From a manufacturing point of view spray-based processes are naturally continuous and can be operated in either continuous mode or semicontinuous mode with specified batch volumes to optimize raw material traceability. The key parameters such as residence times and temperature distributions are well understood and modeled. This ensures the scalability of this manufacturing approach and reproducibility of the materials characteristics.
Many unique compositions and microstructures unattainable by conventional techniques can be synthesized by Cabot’s spray conversion technology with few limitation on types of supports and metal precursors. Most of the typical electrocatalyst compositions derived by conventional precipitation/ impregnation routes can also be produced. |
