New catalyst for methanol fuel cells
01 March 2006
Chinese and Canadian chemists have created what they say is a cheap and efficient catalyst for oxidising methanol that could accelerate the widespread adoption of direct methanol fuel cells (DMFCs).
Methanol has a number of advantages over hydrogen for powering fuel cells, including ease of storage and transport and a higher energy density. But current DMFCs, which work by oxidising methanol at a catalyst-coated anode to produce CO2 and electrons, are less efficient and limited in the amount of power they generate. And methanol oxidation catalysts, most of which are based on platinum, can be difficult and expensive to produce.
Chemists led by Viola Birss at the University of Calgary have designed a relatively simple production process, using acetone as the solvent and ethylene glycol as the reducing agent, to create a methanol oxidation catalyst consisting of platinum, ruthenium and iridium (PtRuIr). The catalyst comprises PtRuIr nanoparticles (about 1nm in diameter) dispersed on the surface of carbon nanotubes.
The researchers report that this catalyst was highly efficient at oxidising methanol and could generate an electric current over four times larger than that generated by a commercially-available catalyst. Further investigation showed that this high level of efficiency was due to the small size of the PtRuIr nanoparticles and their broad dispersal over the carbon nanotubes.
The work marks only an incremental step forward in this growing field, agreed researchers contacted by Chemistry World.
S Liao et al, J. Am. Chem. Soc. (DOI: 10.1021/ja0578653)