APPLICATIONS OF TECHNOLOGY:
- Hydrogen-cooled power plants
- Hydrogen boosting for internal combustion engines
- Small scale, high power applications, e.g., forklift engines
- Fuel cell vehicles
- Earth abundant material
- Tunable organic component can be optimized for performance
- Very low cost
Hydrogen gas derived from water is an ideal carbon neutral and renewable fuel; but to produce it efficiently, the water splitting electrolysis process requires an expensive catalyst such as platinum. A Berkeley Lab team led by chemists Jeffrey Long and Christopher Chang has discovered a highly effective and very low cost alternative catalyst using cobalt nested within the pocket of a carbon-based molecule. Specifically, the researchers have demonstrated that small changes in the structure of the carbon-based molecule surrounding the cobalt atom can enhance its catalytic activity.
In tests, the Berkeley Lab-designed cobalt catalyst produced hydrogen gas from purified water at rates ten to 100 times higher than other known molecular cobalt electrocatalysts operating in neutral aqueous media. The fine-tuning of its carbon-based pocket significantly improved the catalyst’s performance in comparison with its initial molecular design. As measured by its catalytic energy overpotential, where a lower number is better, the fine-tuned molecule was lower by 250-300 mV.
These results demonstrate that this active and long-lived cobalt catalyst is highly tunable, and that changes as subtle as the substitution of a single pyridine ring in the carbon-based pocket molecule produce measurable improvements. The research points toward a menu of additional structural changes that can be expected to produce a succession of even better performing, low cost water splitting catalysts.
While platinum is unsurpassed as a water splitting catalyst, Earth abundant cobalt is about 200 times less expensive. That has stimulated intensive research to find a high performing cobalt catalyst. Those efforts have focused on development of “molecular” catalysts, in which metals such as cobalt are bound in organic, carbon-based molecules that can be chemically modified to improve catalytic activity and open a developmental path toward a cobalt-based catalyst that can perform as well as platinum.
DEVELOPMENT STAGE: Proven principle.
STATUS: Issued U. S. Patent #8,575,345. Available for licensing or collaborative research.
FOR MORE INFORMATION:
Sun, Y., Bigi, J.P., Piro, N.A., Tang, M.L., Long, J.R., Chang, C.J. “Molecular Cobalt Pentapyridine Catalysts for Generating Hydrogen from Water,” Journal of the American Chemical Society 2011, Vol. 133, May 25, 2011.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
REFERENCE NUMBER: IB-3067