It has been synthesised by chemists in the US. Previous attempts to make compounds involving oxygen and metals from groups 9-12 of the Periodic Table, for example gold and silver, have been unsuccessful.

The researchers, at Emory University in Atlanta, said the discovery could help to improve the efficiency of fuel cells, which often use platinum-based electrodes and sometimes rely on platinum-oxygen reactions in operation.

The work appeared in the 25 November edition of Science Express.