Abstract:

The Mn-doped W,V and Bi bimetallic oxide supports were prepared by co-precipitation method.PdCl₂ was used as the active component to prepare supported catalysts for synthesis of DPC by heterogeneous catalytic oxidation of phenol.The structure and properties were characterized by means of gas chromatography,X-ray diffraction,hydrogen temperature programmed reduction and X-ray photoelectron spectroscopy etc..Results showed that with the increase of tungsten-manganese doping ratio and calcination temperature,MnO grew into Mn₃O₄ grains gradually and infiltrated into the lattice of MnO_x.Finally,the catalytic activity was best and the yield of DPC was 5.20% at a doping ratio（amount-of-substance ratio） of 1:1 and calcination at 600 ℃.For vanadium manganese oxide,higher calcination temperature will destroy the integrity of the crystal form,and formation of MnO₂ at a doping ratio of 1:5 at 400 ℃ can significantly improve the property of activity,and the yield of DPC was 10.46%.The bismuth-manganese bimetallic oxide catalyst with doping ratio of 1:5 and calcination at 400 ℃ had the best catalytic effect,the one-way yield of DPC was 13.13%.

Key words: co-precipitation method, bimetallic oxide, oxidative carbonylation method, diphenyl carbonate