Font Size: a A A

Ordered Load Of Gold Nanoparticles Synthesized Mesoporous Carbon-based Catalyst And Its Application

Posted on:2014-07-25Degree:MasterType:Thesis
Country:ChinaCandidate:S WangFull Text:PDF
GTID:2261330398499382Subject:Physical chemistry
Abstract/Summary:PDF Full Text Request
Gold catalyst has attracted much attention by scientists. Especially, goldnanoparticles (Au NPs) with small size have high catalytic activity to selectiveoxidation reaction. But how to get the Au NPs that have concentrated sizedistribution and high stability is still challenging. And supporting Au NPs on carbonmatrix is a difficult work. In this dissertation, we demonstration a route to synthesisAu NPs that have a concentrated size distribution and high stability supported onmesoporous carbon with high surface area, and large pore volume.The whole dissertation has five chapters. The first chapter is literature reviewswhich introduced applied overview of Au NPs, and mesoporous materials.In chapter2, a synthetic procedure is presented for preparing Au NPs that havehigh activity and high stability supported on mesoporous carbon based matrix. Usecopolymer as template, MPTMS as coupling reagent. In which, thiol have strongeffect with gold, silane afford plentiful second-level mesoporous meanwhile. Thecatalyst has ordered2D hexagonal mesoporous structure, high surface area (1826m~2/g), large pore volume (1.19cm~3/g), narrow pore size distrubutons (4nm and2nm), as well as the two level mesoporous interpenetration. Au NPs with9nm embedinto mesoporous carbon symmetrically. The catalyst has high activity for benzylalcohol oxidation in water, using oxygen as oxide, with the condition of60℃andordinary pressure. In which, benzyl alcohol can transform into benzyl acid within12hours and selectivity can be100%. The catalyst has high stability:(1) through600-900℃calcination in nitrogen, there is still ordered mesoporous structure, andthe size of Au NPs have no change;(2) catalyst has high catalytic activity as well asafter it was used5times.In chapter3, a synthetic procedure is presented for preparing Au NPs withcontrolled size from3nm to18nm supported on mesoporous carbon based matrix.Through change the ratio of thiol to gold, and pre-carbonize by concentrated sulfuricacid optionally, it can obtain Au NPs with different size. There are high catalyticactivities for benzyl alcohol oxidation in water, the reaction rate increase with the decrease of Au NPs size. Catalysts have high surface area, large pore volume, andordered mesoporous structure.In chapter4, a synthetic procedure for preparing hybrid polymer-silica matrixsupported Au NPs. To compare different mesoporous matrix, researching thecatalytic performance of gold catalyst. The catalyst has ordered mesoporousstructure, and monodispersed gold nanoparticle embed into mesoporous matrix,with about9nm diameter and symmetrical dispersion. In reduction reaction of4-nitrophenol, the catalyst has high activity.The last chapter is summary of the whole work.
Keywords/Search Tags:heterogeneous catalyst, mesoporous carbon, gold nanoparticle, benzyl alcohol, selective oxidation
PDF Full Text Request
Related items