Years of Cleaner Air : The Evolution of the

The 40th anniversary of the manufacture of the world’s fi rst commercial batch of autocatalysts for passenger cars at Johnson Matthey Plc’s site in Royston, UK, was marked in May 2014. Despite the enormous progress made in reducing the emission of pollutants from vehicles since the 1970s, there has also been considerable recent discussion about the levels of nitrogen oxides (NOx), especially nitrogen dioxide (NO2), and particulate matter (PM) in today’s urban environment. This article describes the evolution of catalyst technologies over the last forty years and the next generation of products which will enable further advances in air quality.