Stable Ir/SiO2 catalyst for selective hydrogenation of crotonaldehyde

► Selective hydrogenation of crotonaldehyde was conducted over Ir/SiO2 catalysts. ► The catalysts did not deactivate during the reaction and reached steady state in 9 h. ► The Ir/SiO2 catalysts contained Ir0 and Irδ+ species. ► Chemical nature of Ir species and surface acidity were important for the reaction.