WOx/C Heterogeneous Catalyst with Oxygen Vacancies and Deficient Brönsted Acid for Epoxidation of 1-Hexene

WO x has good performance in olefin epoxidation, however, the presence of a large amount of Brönsted acid on WO x affects the selectivity of epoxy products. In this paper, broken carbon spheres ( b-C spheres) treated with nitric acid were used as support to anchor WO x in dynamic solvothermal process. Based on GC–MS and GC-IR detection, the obtained WO x /C greatly increased selectivity of 1,2-epoxyhexane from 16.0% ( pure WO x ) to 92.1% in epoxidation of 1-hexene. The improvement of WO x performance is attributed to the reduction of Brönsted acid sites and electron cloud density after loading, which may all result from interaction between WO x and oxygen-containing functional groups of b-C spheres. Above changes not only effectively inhibit the hydrolysis of 1,2-epoxyhexane, but also are conducive to nucleophilic reaction of H 2 O 2 to WO x, which is beneficial to the activation of H 2 O 2 . Finally, an epoxidation mechanism with oxygen vacancies as the main route under WO x /C catalysis is reasonably proposed. Graphical Abstract