High selective epoxidation of 2-methylpropene over a Mo-based oxametallacycle reinforced nano composite

• Published in: Nano research 2023, Vol.16 (1), p.209-218
• Main Authors: Xiong, Chao, Liu, Hao, Zhou, Jie, Xu, Dejing, Liang, Yichao, Zhou, Xiantai, Xue, Can, Ji, Hongbing
• Format: Article
• Language: English
• Subjects: Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Chemistry and Materials Science; Condensed Matter Physics; Materials Science; Nanotechnology; Research Article
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-022-4686-7

Compared with the gas-solid phase reactions, the epoxidation of light olefins in the liquid phase could realize the highly selective preparation of epoxides at a lower temperature. Nevertheless, the C-C bond of light olefins is more difficult to activate, and it is still a challenge to realize the dual activation of the oxidant and light olefins in one reaction system. In this contribution, an oxametallacycle reinforced nanocomposite (Mo(O 2 ) 2 @RT) is prepared via an oxidative pretreatment strategy, and its epoxidation performance to 2-methylpropene in liquid-phase with tert -butyl hydroperoxide (TBHP) as an oxidant is evaluated. A set of advanced characterizations including field emission scanning electron microscopy, X-ray photoelectron spectroscopy, in-situ Fourier transform infrared spectroscopy (FT-IR), electron spin-resonance spectroscopy, and high-resolution mass spectrometer are implemented to confirm the physicochemical properties and the catalytic behaviors of Mo(O 2 ) 2 @RT. This catalyst has a fast kinetic response and exhibits excellent catalytic activity in 2-methylpropene epoxidation to produce 2-methylpropylene oxide (MPO; select.: 99.7%; yield: 92%), along with good reusability and scalability. Moreover, the main epoxidation mechanism is deduced that TBHP is activated by Mo(O 2 ) 2 @RT to generate the highly active tert -butyl peroxide radical, which realizes the epoxidation of 2-methylpropene to yield MPO.