This work reports a facile and efficient seed-mediated method for the synthesis of dendritic platinum （Pt） nanoparticles （NPs） at low temperatures of 55-60 ℃ in water, using L-ascorbic acid as a reducing agent an...This work reports a facile and efficient seed-mediated method for the synthesis of dendritic platinum （Pt） nanoparticles （NPs） at low temperatures of 55-60 ℃ in water, using L-ascorbic acid as a reducing agent and sodium citrate as a capping agent. It is found that the dendritic Pt NPs （10-150 nm） are composed of tiny Pt nanocrystals, which nucleate and grow through the introduced smaller Pt seeds with diameters of 3-5 nm. Further investigation shows that the dendritic Pt nanostructures display excellent catalytic performance in an aqueous-phase aromatic ketone hydrogenation reaction, including： （i） acetophenone conversion rate of 〉 90%, with smaller dendritic Pt NPs （10-46 nm） offering a higher conversion efficiency; （ii） high chemoselectivity toward carbonyl group （90.6%-91.5%）, e.g., the selectivity to l-phenylethanol is -90.1% with nearly 100% acetophenone conversion for 10 nm dendritic Pt NPs within 60 rain, under mild reaction conditions （20 ℃, 1.5 bar H2 pressure, and 1.5 tool% catalyst）. The high catalytic activity, selectivity and stability of the dendritic Pt nanostructures under the organic solvent-free conditions make them promising for many potential applications in green catalytic conversion of hydrophilic biomass derived compounds.展开更多
The title compound C 17 H 14 O, M r =234.30, is orthorhombic, space group Pbca with unit cell of a=16.410 (2), b=15.451(2), c=10.261(2); Z=8, D c =1.196 g/cm 3; V=2601(1) 3; λ (Mo Kα)=0.71069, μ (Mo Kα ) =0.73 cm...The title compound C 17 H 14 O, M r =234.30, is orthorhombic, space group Pbca with unit cell of a=16.410 (2), b=15.451(2), c=10.261(2); Z=8, D c =1.196 g/cm 3; V=2601(1) 3; λ (Mo Kα)=0.71069, μ (Mo Kα ) =0.73 cm -1 , F (000)=992, final R=0.048, R w =0.053 for 1121 observed reflections with I>3.00σ(I ). As the two phenyl planes and the C 4H 4CO group are non coplanar ,the molecular conjugated system was disturbed.展开更多
基金the financial support of the Australian Research Council (ARC) projectsUSyd Early Career Researcher Scheme+2 种基金Major Equipment Schemethe scholarships provided by China Scholarship Council (CSC)the Commonwealth Scientific and Industrial Research Organization (CSIRO) OCE Top-up Scholarship
文摘This work reports a facile and efficient seed-mediated method for the synthesis of dendritic platinum （Pt） nanoparticles （NPs） at low temperatures of 55-60 ℃ in water, using L-ascorbic acid as a reducing agent and sodium citrate as a capping agent. It is found that the dendritic Pt NPs （10-150 nm） are composed of tiny Pt nanocrystals, which nucleate and grow through the introduced smaller Pt seeds with diameters of 3-5 nm. Further investigation shows that the dendritic Pt nanostructures display excellent catalytic performance in an aqueous-phase aromatic ketone hydrogenation reaction, including： （i） acetophenone conversion rate of 〉 90%, with smaller dendritic Pt NPs （10-46 nm） offering a higher conversion efficiency; （ii） high chemoselectivity toward carbonyl group （90.6%-91.5%）, e.g., the selectivity to l-phenylethanol is -90.1% with nearly 100% acetophenone conversion for 10 nm dendritic Pt NPs within 60 rain, under mild reaction conditions （20 ℃, 1.5 bar H2 pressure, and 1.5 tool% catalyst）. The high catalytic activity, selectivity and stability of the dendritic Pt nanostructures under the organic solvent-free conditions make them promising for many potential applications in green catalytic conversion of hydrophilic biomass derived compounds.
文摘The title compound C 17 H 14 O, M r =234.30, is orthorhombic, space group Pbca with unit cell of a=16.410 (2), b=15.451(2), c=10.261(2); Z=8, D c =1.196 g/cm 3; V=2601(1) 3; λ (Mo Kα)=0.71069, μ (Mo Kα ) =0.73 cm -1 , F (000)=992, final R=0.048, R w =0.053 for 1121 observed reflections with I>3.00σ(I ). As the two phenyl planes and the C 4H 4CO group are non coplanar ,the molecular conjugated system was disturbed.
