Plasmon Catalysis on Bimetallic SurfaceSelective Hydrogenation of Alkynes to Alkanes or Alkenes

Utilization of plasmonics as a driving tool for chemical transformation triggering enables to achieve unprecedented results regarding photochemical conversion efficiency and chemical selectivity regulation. In this study, the bimetallic surface plasmon-polariton-supported grating is proposed as an effective background for plasmon-induced hydrogenation of alkynyl groups of absolute chemoselectivity. The periodical bimetallic structure consists of spatially modulated gold layers, covered with the nanometer-thick platinum layer. The alkyne bonds are covalently attached to the surface of the catalytic system through covalent grafting of the bimetallic surface with 4-ethynylbenzenediazonium tosylate, with triple bonds separated from the platinum layer by the benzene rings. The proposed bimetallic structure enables selective hydrogenation of alkyne bonds to alkenyl or alkyl moieties using cyclohexene as a hydrogen source. The selectivity of hydrogenation can be controlled by changing the structure parameters, for example, the thickness of the upper platinum layer.