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A small British clean-tech company has developed a low-cost liquid catalyst that replaces 80% of the platinum inside an automotive fuel cell. Runcorn-based Acal Energy plans to license the technology to tier-one suppliers and OEMs.
The firm said it was in latter-stage discussions with several carmakers to take the technology further. “All the major auto companies are taking this development very seriously,” said chief executive Greg McCray.
The FlowCath technology addresses the inherent limitations of conventional proton exchange membrane fuel cells by applying a poly-oxometallate chemistry-based innovation which replaces the fixed platinum catalysts on the cathode. “This design approach will finally remove the barriers which have prevented traditional hydrogen fuel cells from being truly viable for automotive use,” said McCray.
Hydrogen is catalysed on the anode in the conventional fashion. However, unlike conventional technology, the electron and proton are absorbed into a solution containing redox catalyst systems, which flow continuously from the stack to an external regeneration vessel. In the regenerator, the catholyte comes into contact with air. The electron, proton and oxygen from air react to form water, which exits the regenerator as vapour. The catholyte then flows back to the cell.
So far Acal has carried out more than 8,000 hours of testing on its FlowCath liquid fuel cell – the equivalent of 250,000 road miles – without any degradation. The cell was trialled using a heavy-duty automotive industry standard test consisting of a repeated 40-minute journey.
Traditional proton exchange membrane fuel cells rely on platinum as the catalyst, which over time leads to the cell performance degrading by approximately 28mV per 1,000 hours. “As a result, our design is cheaper, simpler, smaller and more durable than any other hydrogen fuel cell currently on the market,” said McCray. He added that several companies were interested in progressing the technology for use in hydrogen-powered cars. The FlowCath fuell cell would be licensed to such firms, with Acal retaining ownership and distribution of the “secret sauce” chemical compound.
“Taking this sort of technology from lab to street takes money,” said McCray. “We have raised £15 million from investors that include Honda and the Technology Strategy Board and we are involved in second-round funding to raise another £15 million.”