The Preparation Of Graphene And Oxide Supported Gold Nanoparticles And Their Application In Hydration Reaction

The hydration reaction is very important in organic synthesis,which can produce valuable carbonyl derivatives from accessible alkynyl substrates.In recent decades,many organometallic catalysts have been developed and applied successfully for this reaction.However,these noble metal containing catalysts are expensive and difficult to be separated from the reaction system for recycle.Hence,in this account,we designed two novel supported gold nanoparticles composites as catalysts for hydration reaction.The prepared catalysts not only have excellent activity,but also can be recovered and reused easily,which meet the requirement of green chemistry.The main results obtained are as follows:?1?TheAu–SiO₂@Fe₃O₄–RGOcatalystwaspreparedbya deposite-coat-deposite method.The as-prepared sample was characterized by X-Ray Diffraction?XRD?,Transmission Electron Microscopy?TEM?,X-ray photoelectron spectroscopy?XPS?,Inductively Coupled Plasma?ICP?,etc.It was found from the experiment of the hydration of phenylacetylene that the Au–SiO₂@Fe₃O₄–RGO catalyst had excellent catalytic activity.Besides,it can be magnetic recovered easily and resused without significant decrease of activity.?2?A novel composite material?Au–TiO₂–RGO?consisting of ultra-fine gold nanoparticles?⁴.5 nm?grown on a layered titania?TiO₂?and reduced graphene?RGO?hybrid was synthesized.With the assistance of microwave,solid acid(SO₄^2–/TiO₂)was in-situ formed on the surface of TiO₂,and the resulting Au–SO₄^2–/TiO₂–RGO was determined as an enhanced catalyst for the hydration of phenylacetylene.Strong metal–support interaction?SMSI?,the versatile RGO substrate,and the in-situ formed SO₄^2–/TiO₂ account for the excellent performance.Moreover,the catalyst could also be recycled and reused for at least 5 times without obvious deactivation.