The Preparation Of Supported Catalysts Based On Hollow-shell Mesoporous Silicon And Their Catalytic Performance

The use of mesoporous silicon as a carrier to investigate the preparation of supported organometallic catalysts and to study their application in various catalytic reactions has attracted the attention of many researchers.These studies not only facilitate the recycling and recycling of expensive metals,but also obtain highly efficient and highly selective supported catalysts,which have great potential application value.However,conventional mesoporous silicon nanoparticles have the defects of slow transmission speed and reduced catalytic reaction efficiency.Therefore,mesoporous silicon having a shell structure is used as a carrier to construct a supported catalyst,and a large hollow shell can be utilized.It is beneficial to improve the catalytic efficiency of the catalytic reaction,especially in the application of the series reaction.This thesis is aimed at the problem of slow transmission speed of conventional mesoporous silicon nanoparticles.Two kinds of supported catalysts were constructed by using mesoporous silicon with empty shell structure as carrier.The main research contents of this thesis are divided into the following two parts.1)Preparation of mesoporous silica-alumina catalyst with empty shell structure and its application in Michael addition/cyclization and Diels-Alder reaction: copolycondensation method,through orthosilicate and aluminum isopropoxide The condensation obtained a mesoporous silica-alumina catalyst with Lewis acidity and protonic acidity;the Michael addition/ring of the o-aminochalcone compound under mild reaction conditions was optimized by catalytic reaction conditions.High catalytic efficiency in the reaction;this type of catalyst can also be used in the intermolecular Diels-Alder catalytic reaction,showing excellent catalytic performance;the catalyst can be efficiently recycled and reused,and it still shows good performance after repeated use for seven times.Reactivity.2)Preparation of heat-sensitive chiral ruthenium catalyst with empty shell structure and application of asymmetric series reaction in Michael addition/reduction: Mesoporous silicon material with empty shell structure was synthesized by copolycondensation method,and surface functionalization was carried out.The acrylamide temperature-sensitive polymer was successfully prepared with a hollow shell structure of heat-sensitive chiral ruthenium catalyst after loading metal ruthenium.The catalyst has good activity and stereoselectivity in the series reaction of chiral amino alcohol in one step.The yield is up to 90% and the ee value is 96%;the catalyst has certain temperature control characteristics,and the temperature change can be used to control the reaction conversion;the catalyst can be recycled and reused,and the three-dimensional cycle still has a good three-dimensional Selective and catalytic activity.