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Widen the Range of Fuel Cell Operation Across All Conditions and Allow Low Relative Humidity Operation Without Compromising Performance
Automotive fuel cell developers must consider performance across a full range of operating conditions, from low to high relative humidity. Typically, electrocatalysts that perform well at one end of the range perform poorly at the other. This is a serious drawback for stack designers.
Over the past several years Cabot has integrated the use of modified carbon blacks into the manufacturing of high performance next generation fuel cell electrocatalysts. By controlling the type and level of modification Cabot has designed materials for a wide range of operating conditions. Of interest to the automotive industry, Cabot has designed a line of electrocatalyst materials capable of maintaining high performance at very low relative humidity operating conditions.
What is Cabot’s Proprietary Modified Carbon Black Technology?
 Proprietary Technology Allows Cabot to Attach Organic Groups to the Surface of Carbon Black Particles
Modified Carbon Black Technology
Cabot has developed a proprietary technology whereby organic groups can be attached to the surface of carbon black particles. When compared to other traditional methods, such as oxidation and surfactant adsorption techniques, the Cabot process allows for the attachment of a wider range of surface functional groups and enhances the stability of the attachments.
 The types of functional groups that can be attached using Cabot’s chemistry include ionic (sulfonates and carboxylates), polar (glycols, alcohols, esters, ketones), hydrophobic (hydrocarbons, fluorocarbons), and polymeric (acrylates, styrenes, polyethers) groups. By enabling these attachments, Cabot has expanded the range of what is possible with carbon  blacks and can manipulate:
- *The physicochemical properties of the carbon black.
- *The dispersibility of the carbon black particles.
- *The interaction between carbon black particles and different additives, such as Nafion® for fuel cell systems.
Cabot’s unique ability to combine morphology control and now surface modification allows for rational design of carbon black materials.
 Low Relative Humidity Fuel Cell Catalysts
The introduction of hydrophilic groups to the surface of the carbon black (catalyst) particles allows for operation at much lower relative humidities then conventional carbon supported catalyst systems without sacrificing performance. Through the design of the hydrophilic character not only can low RH performance be attained but high performance can be reached at all operating conditions.
Nafion® is a registered trademark of Dupont. |
