Active carbon supported S-promoted Bi catalysts for acetylene hydrochlorination reaction

In the present work, the sulfur doped bismuth-based catalysts were prepared by incipient wetness impregnation method and used for the hydrochlorination of acetylene to vinyl chloride monomer (VCM) in a fixed-bed reactor. The effect of introduction of S was characterized by N-2 adsorption-desorption, powder X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, temperature programmed reduction and X-ray photoelectron spectroscopy. The characterization results indicated that the doping of S resulted in the increase of Brunauer-Emmett-Teller (BET) surface areas and decrease of active species particle size for the Bi-based catalysts, which led to more accessible active sites, and consequently boosted the catalytic hydrochlorination activity. The effect of H2SO4 concentration on the activity of this type catalyst was examined, and the results showed that there is an optimal loading of H2SO4 (S/Bi = 0.5 mol/mol), at which the conversion of C2H2 was enhanced to 81% under the reaction condition and coke deposition is a main reason for the deactivation of catalyst. (C) 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.