动态金属-有机框架材料对铂和金纳米晶的早期形成机制研究

The study of the initial nucleation mechanism of Pt and Au nanocrystals is fairly meaningful to the controllable synthesis and the tunable properities of Pt and Au nanocrystals. In this project, Making fully use of metal–organic frameworks, which could act as “nano single-crystal analytical tool”, supply the host-guest chemical platform to study the initial reaction mechanism of Pt and Au nanocrystals. First, the cationic metal-organic frameworks with well hydrothermal and chemical stability, properly large channels are synthesized, namely generating the “single-crystal container”. Then, utilizing the host materials to trap the intermediates, which were formed in the early nucleation stage of Pt and Au nanocrystals, through ion exchange and single-crystal-to-single-crystal transformation. Meanwhile, the real structures containing the intermediates were obtained via X–ray single crystal diffraction from time to time, and the results could elaborate the initial reaction mechanism of Pt and Au nanocrystals in the nucleation stage. This planning will provide a novel analytical tool and strategy to the initial nucleation mechanism of Pt and Au nanocrystals.

探索铂和金纳米晶的早期成核形成机制对其纳米晶的可控合成和性能调控具有重要意义。本项目针对铂和金纳米晶的早期形成机制，采取基于多孔金属–有机框架可以作为“纳米单晶分析工具”这一主-客化学平台开展研究。首先设计合成具有良好水热稳定性和化学稳定的，并具有适当的大孔道的阳离子型金属–有机框架材料，即“单晶容器”；其次，基于该平台，通过离子交换和单晶到单晶的途径把铂和金的在纳米晶初期成核阶段形成的中间态交换到晶体的孔道内，同时，在该过程中不间断地通过单晶X–射线衍射来获得含有铂和金纳米晶在初始阶段中间体的真实结构，从而阐述铂和金纳米晶在成核阶段的早期形成机制，这就为铂和金纳米晶的早期形成机制研究提供了一种新颖的工具和策略。

本项目通过制备一系列具有高水热和化学稳定性的，并具备低对称性的阳离子型金属–有机框架晶体材料，并成功利用金属–有机框架作为“单晶容器”这一平台来捕获了铂和金纳米晶在最初成核阶段产生的中间体或介稳态，为探索铂和金纳米晶的早期成核阶段发生机制提供了一种直接的证据和新的思路。项目研究期间，在Chem. Commun, J.Mater.Chem.A, J. Mater. Chem. C, Dalton Trans等国内外期刊发表SCI收录论文9篇，其中影响因子4.0以上论文6篇，参加学术会议5次，并作会议报告3次。