Intermetallic PdCu₃ supported on nanodiamond-graphene for semi-hydrogenation of Phenylacetylene

The selective hydrogenation of phenylacetylene to styrene, instead of ethylbenzene, holds significant importance in the polymer industry. However, existing heterogeneous catalysts face the challenge of achieving exceptional activity while maintaining high selectivity. Herein, we introduce a novel intermetallic PdCu3 catalyst supported on defective nanodiamond-graphene (ND@G), showcasing not only high selectivity (95%) but also remarkable activity (turnover frequency: 2940 h(-1), 6 times higher than that of the commercial Lindlar catalyst). Experimental results and DFT calculations reveal that the exceptional selectivity of the catalyst originates from the unique intermetallic structure of PdCu3 with abundant isolated Pd sites on its surface, which favors the rapid desorption of styrene. Simultaneously, the high activity is attributed to the electron transfer from ND@G to PdCu3, facilitating the reduction in the energy barrier of the rate-determining step for styrene formation.