Direct methanol fuel cell

Their main advantage is low temperature operation and the ease of transport of methanol, an energy-dense yet reasonably stable liquid at all environmental conditions.

DMFCs themselves are more efficient at high temperatures and pressures, but these conditions end up causing so many losses in the complete system that the advantage is lost;[5] therefore, atmospheric-pressure configurations are currently preferred.

Methanol cross-over and/or its effects can be alleviated by (a) developing alternative membranes (e.g.[6][7]), (b) improving the electro-oxidation process in the catalyst layer and improving the structure of the catalyst and gas diffusion layers (e.g.[8] ), and (c) optimizing the design of the flow field and the membrane electrode assembly (MEA) which can be achieved by studying the current density distributions (e.g.[9] ).

Other issues include the management of carbon dioxide created at the anode, the sluggish dynamic behavior, and the ability to maintain the solution water.

[11] Freezing of the liquid methanol-water mixture in the stack at low ambient temperature can be problematic for the membrane of DMFC (in contrast to indirect methanol fuel cell).

However, the International Civil Aviation Organization's (ICAO) Dangerous Goods Panel (DGP) voted in November 2005 to allow passengers to carry and use micro fuel cells and methanol fuel cartridges when aboard airplanes to power laptop computers and other consumer electronic devices.

On September 24, 2007, the US Department of Transportation issued a proposal to allow airline passengers to carry fuel cell cartridges on board.

The half-reactions are: Methanol and water are adsorbed on a catalyst usually made of platinum and ruthenium particles, and lose protons until carbon dioxide is formed.

In the case of platinum-ruthenium catalysts, the oxophilic nature of ruthenium is believed to promote the formation of hydroxyl radicals on its surface, which can then react with carbon monoxide adsorbed on the platinum atoms.

A direct methanol fuel cell is usually part of a larger system including all the ancillary units that permit its operation.