Size and Shape Control of Metal Nanoparticles for Reaction Selectivity in Catalysis
Size and Shape Control of Metal Nanoparticles for Reaction Selectivity in Catalysis
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DOI：
10.1002/cctc.201200229
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发表时间：
2012-10-01
期刊：
影响因子：
4.5
通讯作者：
Somorjai, Gabor A.
中科院分区：
文献类型：
--
作者：
An, Kwangjin;Somorjai, Gabor A.
通过胶体化学制备的具有良好定义表面的纳米颗粒，使其能够作为模型异相催化剂进行研究。胶体合成方法提供了多种工具来控制纳米颗粒的大小和形状。传统的成核和生长机制已经被用来理解如何均匀地合成纳米粒子，以及如何控制前所未有的形状。现在，金属颗粒的大小可以通过使用树状聚合物来控制成簇。通过使用种子和外来原子，特定的合成环境，如种子生长和晶体过度生长，可以诱导产生各种形状的单金属或双金属、核/壳或支链纳米结构。对于绿色化学，21世纪催化的目标是100？%的选择性，只生产一种所需的产品在高周转率。近年来对纳米颗粒催化剂的研究清楚地表明，在许多催化反应中，纳米颗粒催化剂的选择性取决于尺寸和形状。通过结合原位表面表征技术，可以在反应环境下对纳米颗粒进行实时监测，从而确定影响催化活性和选择性的几个分子因素。
A nanoparticle with well-defined surfaces, prepared through colloidal chemistry, enables it to be studied as a model heterogeneous catalyst. The colloidal synthetic approach provides versatile tools to control the size and shape of nanoparticles. Traditional nucleation and growth mechanisms have been utilized to understand how nanoparticles can be uniformly synthesized and unprecedented shapes can be controlled. Now, the size of metal particles can be controlled to cluster regimes by using dendrimers. By using seeds and foreign atoms, specific synthetic environments such as seeded growth and crystal overgrowth can be induced to generate various shaped mono- or bi-metallic, core/shell, or branched nanostructures. For green chemistry, catalysis in 21st century is aiming for 100?% selectivity to produce only one desired product at high turnover rates. Recent studies on nanoparticle catalysts clearly demonstrate size and shape dependent selectivity in many catalytic reactions. By combining in situ surface characterization techniques, real-time monitoring of nanoparticles can be performed under reaction environments, thus identifying several molecular factors affecting catalytic activity and selectivity.