中国石油大学的杨朝和与挪威科技大学陈德团队在研究中取得进展。他们的研究通过逆转钛低聚物的形成，实现了含钛分子筛的高效绿色合成。 相关论文于近日发表在《德国应用化学》杂志上。

课题组研究人员报道了一个简单、通用且无添加剂的含钛分子筛（MFI、MEL和BEA）的合成路线。这种方法通过紫外照射原位生成羟基自由基，逆转了钛低聚物的生成，使含钛物种和含硅物种的水解速度互相匹配。使用这种工艺生产的分子筛在催化丙烯与H₂和O₂的环氧化反应中表现出优异的催化活性。与传统的水热合成法相比，这种方法为纯含钛分子筛的高效、环境友好、操作简便的合成提供了新思路。

据介绍，含钛分子筛的绿色高效合成一直受限于需要使用大量对环境有害的添加剂和复杂的合成工艺。这些添加剂和复杂的工艺对于避免合成中发生钛单体低聚化生成锐钛矿TiO₂来说又是必不可少的，这是因为硅前体和钛前体的水解速率不一致。

附：英文原文

Title: Reversing Titanium Oligomers Formation towards High‐Efficiency and Green Synthesis of Titanium‐containing Molecular Sieves

Author: Dong Lin, Quande Zhang, Zhengxing Qin, Qing Li, Xiang Feng, Zhaoning Song, Zhenping Cai, Yibin Liu, Xiaobo Chen, De Chen, Svetlana Mintova, Chaohe Yang

Issue&Volume:

Abstract: Green and efficient synthesis of titanium‐containing molecular sieves is limited by large amount of environmentally unfriendly additives and complicated synthesis procedures necessarily required to avoid the oligomerization of Ti monomers to anatase TiO  2  , due to a mismatch between hydrolysis rates of Si and Ti precursors. Here, we report a simple and generic additive‐free route for the synthesis of Ti‐containing molecular sieves (MFI, MEL, and BEA). This approach successfully reverses the Ti oligomers formation to match hydrolysis rates of Ti and Si species with the assistance of hydroxyl free radicals generated  in‐situ  from ultraviolet irradiation. Moreover, fantastic catalytic performance for propene epoxidation with H  2  and O  2  is observed. Compared with the conventional hydrothermal method, this approach opens up new opportunities for high‐efficiency, environmentally‐benign, and easy‐operating production of pure titanium‐containing molecular sieves.

DOI: 10.1002/anie.202011821

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202011821