The localized surface plasmon resonance (LSPR) excitation in plasmonic nanoparticles has been used to accelerate several catalytic transformations under visible-light irradiation. In order to fully harness the potential of plasmonic catalysis, multimetallic nanoparticles containing a plasmonic and a catalytic component, where LSPR-excited energetic charge carriers and the intrinsic catalytic active sites work synergistically, have raised increased attention. Despite several exciting studies observing rate enhancements, controlling reaction selectivity remains very challenging. Here, by employing multimetallic nanoparticles combining Au, Ag, and Pt in an Au@Ag@Pt core–shell and an Au@AgPt nanorattle architectures, we demonstrate that reaction selectivity of a sequential reaction can be controlled under visible light illumination. The control of the reaction selectivity in plasmonic catalysis was demonstrated for the hydrogenation of phenylacetylene as a model transformation. We have found that the localized interaction between the triple bond in phenylacetylene and the Pt nanoparticle surface enables selective hydrogenation of the triple bond (relative to the double bond in styrene) under visible light illumination. Atomistic calculations show that the enhanced selectivity toward the partial hydrogenation product is driven by distinct adsorption configurations and charge delocalization of the reactant and the reaction intermediate at the catalyst surface. We believe these results will contribute to the use of plasmonic catalysis to drive and control a wealth of selective molecular transformations under ecofriendly conditions and visible light illumination.

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Novel hybrid organic-inorganic catalysts constituted by iron(III) or manganese(III) 5,10,15,20tetrakis(pentafluorophenyl) porphyrin entrapped in an alumina amorphous matrix have been prepared. The hybrid materials were obtained by a non-hydrolytic sol-gel route, through the condensation of aluminium chloride with diisopropyl ether in the presence of metalloporphyrin. The presence of the metalloporphyrin entrapped in the alumina matrix is confirmed by ultraviolet-visible spectroscopy and electron spectroscopic imaging. The material was also analysed by infrared spectroscopy, selected area diffraction, scanning electron microscopy, thermogravimetric analysis and differential thermal analysis, and its surface area was determined. Comparison between the leaching of metalloporphyrin from non-hydrolytic materials and adsorbed metalloporphyrin on commercial neutral alumina confirms that in the non-hydrolytic materials the metalloporphyrin is entrapped and not just adsorbed on the alumina surface. The use of a conventional hydrolytic sol-gel process leads to the complete leaching of the metalloporphyrin from the matrix, underlining the importance of the non-hydrolytic alumina gel process in the matrix preparation. The prepared alumina matrix materials are amorphous, even after heat treatment up 270 uC. The new catalysts prepared were tested for their ability to catalyse the epoxidation of (Z)-cyclooctene using iodosylbenzene as oxygen donor, giving high yields in the epoxidation, similar to those obtained using the metalloporphyrin in solution or supported on a silica matrix.

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