Perovskite LaSrCoFeO6 (LSCF) oxide was investigated as a heterogeneous visible-light catalyst. The material was found to demonstrate highly efficient catalytic performance for the epoxidation of styrene under aerobic conditions.
In the search for a highly efficient heterogeneous catalyst for the epoxidation of styrene, it is still a challenge to develop a system that simultaneously possesses superior catalytic activity and selectivity under aerobic conditions. Herein, we report the use of perovskite LaSrCoFeO6 (LSCF) as a heterogeneous and visible-light catalyst, and determine that LSCF acts as a highly efficient catalyst for the epoxidation of styrene under aerobic conditions. The formation of 1O2 species transformed from O2
.− species were proposed as reactive oxygen species for the epoxidation of styrene over the LSCF catalyst, where the directional generation of O2
.− species on the LSCF catalyst is the key step to yield highly selective epoxidation of styrene. The experimental results of styrene epoxidation show that when the molar ratio of styrene and LSCF catalyst is 150 : 1 and the reaction is under the conditions of visible light (440 nm) and 100 °C for 6 h, the conversion of styrene and selectivity of styrene oxide reached 99.9 % and 80.3 %, respectively. The reaction rate over LSCF catalyst is as high as 50 mmol ⋅ gcat
−1 ⋅ h−1. In addition, the reaction kinetics of the epoxidation of styrene over LSCF catalyst was systematically studied.Zum Volltext