Paraquat provides key to renewable energy

Paraquat is a very promising catalyst for use in fuel cells using plant carbohydrates, offering cheap, clean, renewable energy. Scientists from Brigham Young University (Utah, USA) and NASA have recently published their work in the Journal of the Electrochemical Society¹.

Fuel cells may be attractive sources of energy in future. They are like batteries, but do not store energy – they need a constant source of fuel. Currently, a major stumbling block is the need to use very expensive precious metal catalysts like platinum. Fuel cells using hydrogen as a fuel have received most attention. Their only emission is pure water. The power comes from stripping electrons from hydrogen and using them as electrical current before returning them to react with the bare protons and oxygen to form water. Companies like General Motors are in the vanguard of this technology. To see a demonstration of how their fuel cell works, click here

Hydrogen fuel may be produced from water, but this requires using much fossil energy. However, plant biomassDescription Mass of organic matter of non-fossil biological origin which can be exploited for energy purposes. Authoritative On-line References and Resources http://www1.eere.energy.gov/biomass The US Department of Energy's Office of Energy Efficiency and Renewable Energy has a Biomass Program working with industry, academia and US National Laboratories on research into biomass feedstocks and conversion technologies. The goal is cost competitive, high performance biofuels, bioproducts, and biopower. can be used as a source of renewable hydrogen. The issue here is how to produce the hydrogen in a practically useful and affordable way, but research is progressing at Virginia Tech.

An alternative is to use plant carbohydrates as a direct source of fuel. This is the goal of Professor Gerald Watt at Brigham Young University.

Professor Watt² and his team have found that the electron pulling power of paraquat, which makes it such a fast and effective herbicide, can be harnessed to make a cheap and efficient fuel cell. Paraquat, originally synthesised as a dye called methyl viologen, is added to the cell as the catalyst.

Since the paper just published was written, the team have already doubled the output of power from paraquat fuel cells and are working to improve the commercial potential of the technology. 

Notes

1. Wheeler, D R, Nichols, J, Hansen, D, Andrus, M, Choi, S & Watt, G D (2009). Viologen catalysts for a direct carbohydrate fuel cell. J. Electrochem. Soc., 156, (10), B1201-B1207
2. Professor Watt might be said to have power in his blood being related to Scottish inventor James Watt who gave his name to the unit of power!