Barium hollandite-type compounds BaxFe2xTi8-2x O16 with x=1.143 and 1.1333

A quarter of a century ago the first autocatalysts were manufactured on a commercial scale by Johnson Matthey at Royston, near Cambridge, in England. This article looks at the background to this major contribution towards cleaning urban air and briefly traces the progress of car catalyst technology since the work of the early autocatalyst pioneers.