C2H2 semi-hydrogenation over the supported Pd and Cu catalysts: The effects of the support types, properties and metal-support interaction on C2H4 selectivity and activity

•The support type and property affect the catalytic performance of C2H2 semi-hydrogenation.•Anatase and rutile TiO2 supported Pd catalysts present better catalytic performance.•The oxygen-vacancy of the anatase and rutile TiO2 show the crucial function.•The supported Cu catalyst cannot effectively improve the catalytic performance.•Supported Pd catalysts have stronger metal-support interaction than the supported Cu catalyst.