Chemistry and lightning quick reactions are under discussion this week as Emma Schofield explains what a catalyst is, how catalytic converters work and how catalysts can help to clean up the atmosphere, and Fraser Armstrong discusses fuel cells, using hydrogen as a fuel and how enzymes naturally found in bacteria are making hydrogen a more realistic energy source for the future. In Kitchen Science, both guests are used as guinea pigs as Dave Ansell demonstrates the wonder of enzymes with nothing but a slice of bread... Like this podcast? Please help us by supporting the Naked Scientists