Crystal-plane effects of anatase TiO2 on the selective hydrogenation of crotonaldehyde over Ir/TiO2 catalysts

•Catalytic performance of Ir/TiO2 catalysts depended on the crystal plane of TiO2.•Ir/TiO2-{101} catalyst gave 4-fold higher activity than that of Ir/TiO2-{001} catalyst.•The defects sites of TiOx support were responsible for the formation of crotyl alcohol.•Ir-TiOx interfacial sites may account for the formation of 1-butanol.