A cell that simultaneously uses microwave radiation to heat a reaction and infrared spectroscopy to monitor its progress has been developed by UK scientists.

Gordon McDougall and colleagues at the University of Edinburgh made the cell, which can be mounted in an infrared spectrometer and is designed to let an infrared beam pass through the reaction that is being followed.

The device contains two parallel plates that apply microwave radiation to any microwave absorbing material between them, in this case the contents of a ceramic sample holder. A platinum catalyst is housed inside the sample holder and reactant gases are channelled over the catalyst.

The team used the cell to heat the catalyst and carbon monoxide with microwaves. They could monitor the reaction by recording changes in the infrared spectrum at the same time. These showed that the carbon monoxide was adsorbing onto the catalyst and being oxidised to carbon dioxide. This was confirmed by recording the mass spectrum of the exhaust gases as they left the cell.

McDougall explained that he has been working in the area of in situ infrared methods for studying catalysis for years, but that he is 'more interested in developing the method than routinely applying it'.

Rachel Warfield