Synthesis of a self‐assembled Mn 3 O 4 nanostructure aerogel for the adsorption and oxidative carbonylation of phenol to diphenyl carbonate

Abstract

Mn3O4 nanostructure aerogels have been successfully synthesised through an epoxide-driven sol–gel method with thioacetamide as precursors, followed by lyophilising (freeze drying). The prepared nanostructures were characterised by power X-ray diffraction pattern, scanning electron microscopy, energy dispersive X-ray analysis, surface area measurement (Brunauer–Emmett–Teller) and high-resolution transmission electron microscopy. The cauliflower-like and spheroidic morphologies Mn3O4 nanostructure aerogels can be successfully synthesised under different experimental conditions. The growth mechanism for different nanostructures is proposed. The cauliflower-like Mn3O4 aerogel exhibited higher adsorption capacity for methylene blue and phenol than the spheroidic Mn3O4 aerogel. In addition, the cauliflower-like Mn3O4 aerogel is a novel co-catalyst which is more effective for oxidative carbonylation of phenol to diphenyl carbonate. It may be attributed to the largest surface area and the nanostructure of the cauliflower-like Mn3O4 self-assembled by small nanoparticles. This work points out the way to develop a novel and more active self-assembled nanostructure aerogel co-catalyst for oxidative carbonylation of phenol to diphenyl carbonate.