合成不同尺寸鉑奈米粒子以及在催化反應的應用

Size-Controlled Synthesis of Platinum Nanoparticles and Applications to Catalysis

曾凱群(Kai-Chiun Tseng)

指導教授 ： 吉凱明

國立中正大學/理學院/化學暨生物化學系/碩士(2012年)

摘要

奈米材料由於具有大量的表層原子，所以催化活性表現上會相當的優異。本篇論文是探討鉑奈米粒子的催化活性，首先合成出具有大小均一、分散性極佳的鉑奈米粒子，針對這些鉑奈米粒子進行氫化反應的研究。
在此之前本實驗室成功地利用Pt(acac)2和Pt(hfac)2熱裂解還原方法合成約 5~15 nm的鉑奈米粒子。本實驗利用Pt(hfac)2做為前驅物並調整各種反應條件，合成更多樣的鉑奈米粒子。調控溶劑、界面活性劑種類、界面活性劑與前驅物不同比例、前驅物濃度，成功的製備出 2、5、10、25 nm 四種大小均一、分散性佳的鉑奈米粒子。
再利用所合成出的鉑奈米粒子來去探討環己烯的氫化反應，找出最好的TOF值。最後結果與預期一致，奈米粒子尺寸越小，有越好的催化表現。在催化反應中，鉑奈米粒子經過第一回合後，產生聚集現象，造成催化活性變弱。

關鍵字

奈米材料

並列摘要

Nano-materials have a mass of atoms on the surface, so they have excellent catalytic activities. This study was going to explore the catalytic activity of platinum nanoparticles. Platinum nanoparticles with a uniform size and excellent dispersion were synthesized and then were examined their catalytic activity for hydrogenation of alkene.
Successful synthesis of platinum nanoparticles of about 5 ~ 15 nm by pyrolysis of Pt(acac)2 and Pt(hfac)2 has been achieved in our laboratory prior to this study. Herein, we used Pt(hfac)2 as a precursor and adjusted a variety of reaction conditions to synthesize platinum nanoparticles with different sizes and morphologies. Regulation of solvent, surfactant, ratio of the precursor/surfactant and precursor concentration successfully afforded four types of size-uniform, well-dispersed platinum nanoparticles with the size of 2, 5, 10, 25 nm.
We used these Pt nanoparticles to study the hydrogenation reaction of cyclohexene, and to find the best TOF values. The final results were in line with expectations – the smaller the nanoparticle size, the better the catalytic performance. Aggregation of the platinum nanoparticles was observed after the first round of hydrogenation and it resulted in the weakening of the catalytic activity.

並列關鍵字

Nano-material

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