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Selective and Efficient Olefin Epoxidation by Robust Magnetic Mo Nanocatalysts

Selective and Efficient Olefin Epoxidation by Robust Magnetic Mo Nanocatalysts

Authors :
Cristina I. Fernandes
Carla D. Nunes
Pedro D. Vaz
Source :
Catalysts, Vol 11, Iss 380, p 380 (2021), Catalysts, Volume 11, Issue 3
Publication Year :
2021
Publisher :
MDPI AG, 2021.

Abstract

Iron oxide magnetic nanoparticles were synthesized with different sizes (11 and 30 nm). Subsequently they were shelled with a silica layer allowing grafting of an organic phosphine ligand that coordinated to the [MoI2(CO)3] organometallic core. The silica layer was prepared by the Stöber method using either mechanical (both 11 and 30 nm nanoparticles) or ultrasound (30 nm only) stirring. The latter nanoparticles once coated with silica were obtained with less aggregation, which was beneficial for the final material holding the organometallic moiety. The Mo loadings were found to be 0.20, 0.18, and 0.34 mmolMo·g−1 for MNP30-Si-phos-Mo,MNP11-Si-phos-Mo, and MNP30-Sius-phos-Mo, respectively, with the ligand-to-metal ratio reaching 4.6, 4.8, and 3.2, by the same order, confirming coordination of the Mo moieties to two phos ligands. Structural characterization obtained from powder X-ray diffraction (XRD), scanning electron microscopy (SEM)/ transmission electron microscopy (TEM) analysis, and Fourier-transform infrared (FTIR) spectroscopy data confirmed the successful synthesis of all nanomaterials. Olefin epoxidation of several substrates catalyzed by these organometallic nano-hybrid materials using tert-butyl hydroperoxide (tbhp) as oxidant, achieved very good results. Extensive testing of the catalysts showed that they are highly active, selective, recyclable, and efficient concerning oxidant consumption.

Details

ISSN :
20734344
Volume :
11
Database :
OpenAIRE
Journal :
Catalysts
Accession number :
edsair.doi.dedup.....b4334a0baf25b4fdb75d183742e5b5f4
Full Text :
https://doi.org/10.3390/catal11030380