Comparation of Cu-Co-Mn Mixed Oxides and Hopcalite as Support in Synthesis of Diphenyl Carbonate by Oxidative Carbonylation of Phenol

Abstract

The difference of Cu-Co-Mn mixed oxides and hopcalite as support in synthesis of diphenyl carbonate by oxidative carbonylation of phenol was studied. The catalysts were characterized by transmission electron microscopy, scanning electron microscopy, X-ray power diffraction, and X-ray photoelectron spectroscopy. The results show that the average particle diameter of the former catalyst is about 40 nm, whereas the other catalyst is about 0.5 μm. The main crystal phase in the former catalyst is Co2MnO4and Pd0.5Pd3O4, which in the latter catalyst is CuMn2O4, CoMn2O4and Pd0.5Pd3O4.The oxygen atoms lose electrons and form oxygen vacancies in.Pd0.5Pd3O4and Co2MnO4of the former catalyst, which destroys the crystal integrity and prompts the oxygen adsorption on the crystal surface. The oxygen atoms lose electrons and form oxygen vacancies in.Pd0.5Pd3O4of the latter catalyst. Finally, it was found that the difference of the yield and selectivity of the both catalysts was not remarkable.

Pd catalyst supported on CeO2 nanotubes with enhanced structural stability toward oxidative carbonylation of phenol

“…3 Hitherto, the main focus of research involving oxidative carbonylation of phenol lies in developing heterogeneous catalysts to enhance repeatability and to facilitate the separation of catalysts from products. 4 Generally, it is commonly accepted that palladium is the most active species toward the oxidative carbonylation reaction, therefore, a number of heterogeneous palladium catalysts anchored on supports including activated carbon, polystyrene, silicon dioxide, layered double hydroxides, organic-inorganic hybrid materials and mixed metal oxides have been developed. 5 Zhang et al 6 reported that the Pd/PbO-MnFe 2 O 4 catalyst, prepared via a coprecipitation method, demonstrated high catalytic activity with a turnover frequency reaching 70.56 mol DPC (mol Pd h) À1 toward the oxidative carbonylation of phenol.…”