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

Aiming at identifying the effects of the support types, properties and the metal-support interaction of the supported catalysts on C2H4 selectivity and its formation activity for C2H2 semi-hydrogenation, the corresponding mechanism over the supported Pd and Cu catalysts with different supports are fully studied based on DFT calculations. This work indicates that the support types and properties change the selectivity of C2H4 and its formation activity, for the supported Pd catalysts, the oxygen-vacancy anatase and rutile TiO2 supports present much better selectivity of C2H4 and its formation activity than the pure Pd catalyst does; especially, the anatase exhibits better catalytic performance than the rutile, in which the oxygen-vacancy show the crucial function. For the supported Cu catalysts, gamma-Al2O3 is unable to enhance C2H4 selectivity compared to the pure Cu catalyst, whereas MgO support improves C2H4 selectivity but reduces its formation activity. Further, the metal-support interaction of the supported Pd catalysts are much stronger than that of the supported Cu catalyst, which results in better activity and selectivity of C2H4 over the supported Pd catalysts. This study can give out a valuable clue for the preparation of the supported Pd or Cu catalysts with better performance in C2H2 semi-hydrogenation.