Battery

Progress is made on methanol fuel cell catalysts

Methanol fuel cells are gaining traction as a viable alternative to batteries, based on their quick recharge rates and promise of instant power while away from the plug. Both Sony and MTI Micro have promised to bring methanol fuel cells to market, with MTI Micro stating that it will be selling fuel cells by next year. However the cells remain pricey and are not optimally efficient, limiting their power output, lifetime, and potential.

University of the Basque Country (UPV/EHU) research chemist, José E. Barranco hopes to make methanol fuel cells more viable. For his PhD research he has developed improved catalysts that can be put to use in the cells. Catalysts accelerate the rate of chemical reaction, allowing cells to have potentially higher outputs. Barranco, who currently works at Polytechnic University School in the Basque city of Donostia-San Sebastián, developed new amorphous metallic catalysts that should help the burgeoning methanol fuel cell industry.

While methanol fuel cells are a hot topic certainly, more research effort and money has gone into perfecting hydrogen fuel cells. Barranco argues that methanol fuel cells are advantageous to hydrogen ones in a variety of ways as methanol has superior energy density, is more cheaply produced, and does not need to be pressurized.

During the fuel cell’s operation power is generated by electro-oxidation reactions. These reactions occur at special membranes that expose gases to each other, but prevent them from completely mixing. Catalysts are placed in these membranes to speed these reactions. Platinum is a typically used catalyst as it provides a good boost. However it is extremely expensive. Additionally, carbon monoxide from reactions bonds to platinum, impeding the catalyst’s function.

Barranco’s research focused on minimizing the platinum used. He devised a catalyst with 1 percent platinum, composed of nickel, niobium, antimony or ruthenium and other metals. The new catalyst was cheaper and also catalyzed a new reaction — the conversion of carbon monoxide to carbon dioxide, helping safeguard the catalyst from deterioration. Barranco points out that while this means the cell will emit the greenhouse gas, a car engine powered on a methanol fuel cell would release less carbon dioxide than a typical petrol engine.

Further progress was made by Barranco when amorphous platinum was used for the small platinum content. The new amorphous material was 80 to 100 times better at speeding the reaction than crystalline platinum, due its disordered structure. Further, it resisted corrosion better than traditional platinum. Amorphous platinum can be produced by sudden cooling of heated crystalline platinum.

Finally, Barranco designed a unique delivery form for the catalyst, making it into a very fine powder, placed in a can, which could essentially be spray painted on. In tests, it was revealed that this approach yield 9 to 13 times the operational capacity of larger particle catalysts typically used.

The end result is that fuel cell efficiency is improved 50 percent. Barranco is currently working with other researchers to further improve the overall methanol fuel design.

While some people scoff at such developments as they regularly occur and take years to reach the market, it is such iterative improvements that delivered the modern PC and the modern combustion engine. With Barranco and others delivering terrific advancements in fuel cell technology, these advances will eventually culminate in the form a valuable commercial product.

dailytech.com