Nat. Protoc. 10, 916–926 (2015); published online 21 May 2015; corrected after print 16 September 2015

In the version of this article initially published, Box 1 had the incorrect title; the correct title is 'Catalyst recycling experiments with nitrobenzene: 30 h.' The error has been corrected (for both the Box itself and the corresponding entry in the Timing section) in the HTML and PDF versions of the article.