Synthesis of Vinyl Chloride Monomer over Carbon-Supported Tris-(Triphenylphosphine) Ruthenium Dichloride Catalysts

A series of catalysts, including Ru/AC, Ф-P-Ru/AC, Ф-P-Ru/AC-HCl, and Ф-P-Ru/AC-HNO3, were prepared and evaluated for the hydrochlorination reaction of acetylene. The test results reveal that the Ф-P-Ru/AC-HNO3 catalyst shows superior catalytic performance with an initial acetylene conversion of 97.2% and a relative increment of 87.0% within 48 h in comparison with that of the traditional RuCl3 catalyst. The substitution of inorganic RuCl3 precursor by organic Ф-P-Ru complex species in the catalysts results in more active species and tends to confine them in the micro-pores; the modification of carbon support by nitric acid in Ф-P-Ru catalyst may produce an interaction between the functional groups on modified support and Ru species, which is favorable to anchor and then reduce the loss of active species during the reaction, further increasing the amount of dominating Ru species, and greatly improving the reactants adsorption ability on the catalysts, thus enhancing the performance of the resultant catalysts. The as-prepared Ф-P-Ru catalysts are shown to be promising mercury-free candidates for the synthesis of vinyl chloride monomer.