Precision Hydrogenation of Acetophenone to Phenylethanol over Pd ₁ -(CuO x ) ₁ Hybrid Nanoparticles Confined in KIT-6 Channels

Modifying noble metal catalysts with transition metal oxides (MOx) is an effective strategy to enhance both catalytic activity and selectivity through interfacial synergy. However, achieving precise spatial colocalization of the metal and oxide phases remains a challenge. Herein, Pd1-(CuOx)1 hybrid nanostructures confined within KIT-6 mesoporous silica were rationally synthesized via in situ oxidative transformation of PdCu bimetallic nanoparticles (NPs) under controlled thermal treatment. The resulting Pd1-(CuOx)1/KIT-6 catalysts exhibited markedly enhanced activity and chemoselectivity for the hydrogenation of acetophenone to 1-phenylethanol compared with monometallic Pd/KIT-6 and PdCu/KIT-6. The optimal catalyst with a Pd/Cu molar ratio of 1:1 achieved 93.1% acetophenone conversion and 98.2% selectivity toward 1-phenylethanol, and demonstrated broad applicability across a range of ketone substrates. Comprehensive structural characterization revealed that the Pd-CuOx interfacial sites are central to the observed performance enhancement: metallic Pd facilitates H2 dissociation, while adjacent CuOx species are proposed to facilitate carbonyl adsorption, contributing to the overall synergistic enhancement. This interface-driven synergistic mechanism provides a general, efficient, and cost-effective strategy for the selective hydrogenation of multifunctional molecules.