Corrosion Resisitant Carbon Supports for Fuel Cell Electrocatalysts

The Power to Break Through Durability Barriers for Fuel Cells

Figure 1. Protocol for measuring corrosion of fuel cell carbon supports.

Carbon support durability is considered to be a major barrier for commercialization of automotive fuel cells. For automotive and PEM fuel cell developers, achieving commercial system lifetimes without undue compromise in stack cost, size and performance is absolutely essential. Achieving breakthrough success in system durability is harder than ever, yet is the key to accelerating fuel cell commercialization.

Figure 2. Demonstration of severe performance losses with standard carbon supports.

Carbon corrosion is accelerated during start/stop cycles where potentials at the cathode can reach 1.4V and at high temperature conditions resulting in performance loses related to:

Platinum sintering due to loss of active phase/support interaction.
Oxidation of carbon surface leads to layer flooding effects.
Break down in carbon/carbon interface.

Until now, the carbon support particles available to the fuel cell industry have been the same carbon particles designed for other mass market applications, such as in tires, hoses and other commodity products. Cabot Fuel Cells, working intimately with Cabot Corporation’s Technology Center, is addressing the specific challenges and needs of the fuel cell industry with carbon support particles designed ground-up as electrocatalyst supports. In addition to Cabot Fuel Cells’ world-class competencies in electrocatalysts, Cabot Corporation is the recognized global leader in carbon particle technology for the entire range of application of carbon and fine particle materials.

Figure 3. Comparison of Cabot 60% Pt/KB vs. Cabot 60% Pt/CRC.

Cabot’s new corrosion resistant electrocatalyst incorporates a new high surface area carbon material designed for fuel cell applications that delivers superior resistance towards oxidation while also delivering state-of-the-art levels of absolute performance and precious metal utilization.

Figure 4. Comparison of performance and corrosion durability of Cabot Modified Carbon Black and Corrosion Resistant Carbon catalysts.

With a goal of less then 30 mV loss at 1 A/cm2 after 100 hours, standard support materials are far from meeting the performance specification.

Cabot’s novel corrosion resistant fuel catalyst, however, are quite different.

Cabot CRC materials demonstrate identical initial performance as standard supported fuel cell catalysts, however, after 100 hours of corrosion testing there is no loss in performance.