at Google ScholarTitle data
Gordon, Christopher P. ; Engler, Hauke ; Tragl, Amadeus Samuel ; Plodinec, Milivoj ; Lunkenbein, Thomas ; Berkessel, Albrecht ; Teles, Joaquim Henrique ; Parvulescu, Andrei-Nicolae ; Copéret, Christophe:
Efficient epoxidation over dinuclear sites in titanium silicalite-1.
In: Nature.
Vol. 586
(2020)
.
- pp. 708-713.
ISSN 1476-4687
DOI: https://doi.org/10.1038/s41586-020-2826-3
Abstract in another language
Titanium silicalite-1 (TS-1) is a zeolitic material with MFI framework structure, in which 1 to 2 per cent of the silicon atoms are substituted for titanium atoms. It is widely used in industry owing to its ability to catalytically epoxidize olefins with hydrogen peroxide (H2O2), leaving only water as a byproduct(1,2); around one million tonnes of propylene oxide are produced each year using this process(3). The catalytic properties of TS-1 are generally attributed to the presence of isolated Ti(iv) sites within the zeolite framework1. However, despite almost 40 years of experimental and computational investigation(4-10), the structure of these active Ti(iv) sites is unconfirmed, owing to the challenges of fully characterizing TS-1. Here, using a combination of spectroscopy and microscopy, we characterize in detail a series of highly active and selective TS-1 propylene epoxidation catalysts with well dispersed titanium atoms. We find that, on contact with (H2O2)-O-17, all samples exhibit a characteristic solid-state O-17 nuclear magnetic resonance signature that is indicative of the formation of bridging peroxo species on dinuclear titanium sites. Further, density functional theory calculations indicate that cooperativity between two titanium atoms enables propylene epoxidation via a low-energy reaction pathway with a key oxygen-transfer transition state similar to that of olefin epoxidation by peracids. We therefore propose that dinuclear titanium sites, rather than isolated titanium atoms in the framework, explain the high efficiency of TS-1 in propylene epoxidation with H2O2. This revised view of the active-site structure may enable further optimization of TS-1 and the industrial epoxidation process.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Additional notes: | WOS:000623956700002 |
| Institutions of the University: | Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry Faculties Faculties > Faculty of Biology, Chemistry and Earth Sciences Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Operando-Analytics of Electrochemical Energy Storage > Chair Operando-Analytics of Electrochemical Energy Storage - Univ.-Prof. Dr. Thomas Lunkenbein |
| Result of work at the UBT: | No |
| DDC Subjects: | 500 Science > 540 Chemistry |
| Date Deposited: | 13 Jun 2025 06:53 |
| Last Modified: | 04 Jul 2025 11:32 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/93695 |