Defective ceria created by oxy-hydrogen flame and its influences on Pt dispersion, Pt-ceria interaction and catalytic hydrogenation

•An oxy-hydrogen flame was used to create defects (i.e., Ov and Ce3+) in ceria.•Defective CeO2-x is more reduced and has greater redox capabilities than CeO2.•Defective ceria supported Pt catalyst has strong metal-support interactions.•Defective ceria supported Pt catalyst has higher Pt dispersion and chemoselectivity.•A volcano relationship exists between chemoselectivity and Pt loading in Pt/ceo2-x.