Downloadable PDF from Johnson Matthey showing the timeline of catalytic converter technology.
You can download here
http://ect.jmcatalysts.com/pdfs-library/Johnson%20Matthey%2040%20Years%20of%20Cleaner%20Air%202014.pdf (opens in new window)
or directly below (8.5Mb)
Johnson Matthey 40 Years of Cleaner Air 2014.pdf