Fuel cells and catalytic waves - combustion demise... fuel cell rise
The cell bus runs on pure hydrogen (Ballard Power Systems)
Professor Kevin Kendall, Professor Andy King, Professor Gary Acres, Professor Jonathan Seville and Professor Rex Harris.
University of Birmingham.
By the end of this century, fiery combustion in vehicle engines and power stations may be banned to curb climate change caused by greenhouse gases. In such a flame-free future, we could turn to a 160-year-old idea for power that is just coming of age - the fuel cell.
Fuel cells convert the chemical energy of their fuel into electrical energy far more efficiently than the flashes and bangs of conventional combustion and produce almost no pollution. Several companies are now developing fuel cells to replace internal combustion engines and fossil-fuel power plants.
This exhibit demonstrates how fuel cells work, where they are being used and how they might be used in the future. 'We'll have a completely different view of power coming from chemical energy,' predicts Professor Kevin Kendall of the University of Birmingham, who leads the UK Fuel Cell Network linking researchers in universities and industry.
Sir William Grove first described the principles of the fuel cell in 1839. A fuel cell consists of two electrodes separated by an electrolyte - a substance that conducts electrical ions. Supplying a fuel such as hydrogen to one electrode and an oxidant such as oxygen to the other electrode allows the electrochemical equivalent of combustion to take place. The fuel and the oxidant react across the electrolyte, releasing a flow of electrons that can be tapped to provide electrical energy.
There are several different designs of fuel cell, which have different sizes and run at different temperatures so they are suitable for different applications. The proton exchange membrane (PEM) fuel cell is perhaps the most promising replacement for the internal combustion engine in vehicles. Its only waste product is water when pure hydrogen is used as a fuel. Buses powered by PEM fuel cells will hit the streets of London on trial later this year, built by DaimlerChrysler and operated by Firstbus. Honda has also developed a PEM fuel cell car for sale in California, where environmental legislation will require that 10 per cent of new cars are zero-emission vehicles - either powered by rechargeable batteries or fuel cells.
Other types of fuel cells harvest hydrogen fuel from other substances. Direct methanol fuel cells use a catalyst to extract hydrogen from methanol at room temperature. This type of fuel cell could soon replace...