常温醇环境中离子交换原位还原制备Pd-核壳型玻璃微珠催化剂

项目名称： 常温醇环境中离子交换原位还原制备Pd-核壳型玻璃微珠催化剂

项目编号： No.21276140

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 化学工业

项目作者： 王玉军

作者单位： 清华大学

项目金额： 80万元

中文摘要： 该项目旨在发展一种在室温下制备钯核壳型催化剂的新方法，可以实现纳米钯颗粒在具有核壳结构的玻璃微珠上的单分散负载。该方法的创新性在于：通过离子交换将Pd负载在玻璃微珠上，与一般的浸渍法相比，有助于得到更小的Pd纳米颗粒；由于玻璃微珠具有碱性，可在常温下催化Pd离子和醇羟基的反应，使得Pd离子原位还原得到单质Pd，避免了使用高温氢气还原；通过改变溶剂环境（由水改变为乙醇）抑制了Pd离子解离，大大提高了Pd的负载量；核壳型结构可以减小扩散阻力，提高加氢反应选择性。初步的研究结果表明：在乙醇环境中得到的纳米钯颗粒拥有面心立方体结构且其平均粒径为3.75nm，玻璃微球上钯离子负载量可达55.0mg/g，与在水溶液中负载量相比提高了26倍。该项目拟研究核壳型结构、Pd初始浓度、醇种类等因素对Pd负载量和粒径的影响规律，探究离子交换原位还原的耦合机理，并以蒽醌加氢为实验体系，研究该新型催化剂的加氢性能。

中文关键词： 玻璃微球；核壳结构；原位负载；催化加氢；

英文摘要： This project aims to develop a novel in-situ method to prepare mono-dispersed palladium nanoparticles supported on porous glass beads with an egg-shell structure at room temperature. The innovation of this method mainly contains four points: firstly, palladium ions are loaded on the surface of the porous glass beads through the ion exchange process,it is easier to obtain nanoparticles with smaller size and narrow size distribution compared with the impregnation method; secondly, using porous glass beads as the solid base catalyst, the reduction of palladium ions is realized at room temperature instead of reducing by hydrogen gas at high temperature (573 K); thirdly, the change in solvent (from water to ethanol) weakens the competing effect of hydrogen ions, resulting in an larger loading amount of palladium nanoparticles; fourthly, the egg-shell structure would greatly enhanced mass transfer and selectivity. Preliminary results showed that in enthanol,the mono-dispersed Pd nanoparticles around 3.75 nm in diameter with a face-centered cubic structure have been successfully prepared. The adsorption capacity for palladium reached 55.0 mg/g in ethanol which was 26 times larger than that in water. This project will investigate the effects of the egg-shell structure, concentration of Pd2+ ions, type of solvent on the

英文关键词： glass bead；core-shell structure；in-situ loading；catalytic hydrogenation；