Synthesis of lathanum or La-B doped KIT-6 mesoporous materials and their application in the catalytic oxidation of styrene

Abstract

La-doped and La-B-doped KIT-6 mesoporous materials were prepared by direct hydrothermal synthesis with pH-adjusting method and characterized by X-ray diffractometer (XRD), nitrogen sorption, FT-IR, UV-Vis, X-ray photoelectron spectroscopy (XPS) and ICP-AES. The catalytic performance for the oxidation of styrene by hydrogen peroxide, tert-butyl hydroperoxide or oxygen was investigated. The results showed that the introduction of heteroatoms did not destroy the mesostructure of KIT-6 with cubic Ia3 d space group. La or B cations were incorporated into the framework of KIT-6 and the coexistence of B could hinder the dispersion or incorporation of La into the framework. La 3+ species in the framework of La-KIT-6 promoted the catalytic performance of La-KIT-6 catalyst for the oxidation of styrene. H 2O 2 is the better oxidant for the oxidation of styrene than tert-butyl hydroperoxide and oxygen, in which the styrene conversion of 20.6% and the selectivity to benzaldehyde of 74.6% were achieved over La-KIT-6-0.02.