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The addition of yttrium chloride(YCl_3) to an activated carbon-supported Au catalyst(Au/AC) can markedly promote the catalytic performance of acetylene hydrochlorination to the vinyl chloride monomer(VCM), The structure and physicochemical features of the YCl_3-modified catalysts(Y-Au/AC)were measured by X-ray diffraction, X-ray photoelectron spectroscopy, temperature-programmed reduction, C_2 H_2-temperature programmed desorption, and scanning transmission electron microscopy.The presence of YCl_3 was found suppressing the reduction of highly oxidized Au~(δ+)(δ=1,3) to metallic Au~0 dependently and thus retard the agglomeration of Au nanoparticles during the reaction. In addition,the additive of YCl_3 to the Au/AC catalyst greatly inhibits the coke deposition on the catalyst surface. The optimized catalyst with an atomic ratio of Y/Au = 5(1 wt% Au loading weight) yields an 87.8% acetylene conversion and almost 100% selectivity for VCM under the reaction of GHSV(C_2 H_2) = 800 h~(-1) at 180 ℃.The durability test indicates that the 5 Y-1 Au/AC catalyst maintains high catalytic activity for more than2300 h at 30 h~(-1) GHSV(C_2 H_2) and 180 ℃, indicating great promise as a non-mercury catalyst for PVC manufacture.
The addition of yttrium chloride (YCl_3) to an activated carbon-supported Au catalyst (Au / AC) can markedly promote the catalytic performance of acetylene hydrochlorination to the vinyl chloride monomer (VCM), The structure and physicochemical features of the YCl_3-modified catalysts (Y-Au / AC) were measured by X-ray diffraction, X-ray photoelectron spectroscopy, temperature-programmed reduction, C 2 H 2 -temperature programmed desorption, and scanning transmission electron microscopy.The presence of YCl 3 was found to suppress the reduction of highly oxidized Au ~ (δ +) (δ = 1,3) to metallic Au ~ 0 dependently and thus retard the agglomeration of Au nanoparticles during the reaction. In addition, the additive of YCl_3 to the Au / AC catalyst greatly inhibits the coke deposition The optimized catalyst with an atomic ratio of Y / Au = 5 (1 wt% Au loading weight) yields an 87.8% acetylene conversion and almost 100% selectivity for VCM under the reaction of GHSV (C_2 H_2) = 800 h ~ (-1) at 180 ° C, indicating that the 5 Y-1 Au / AC catalyst maintains high catalytic activity for more than 2300 h at 30 h -1 GHSV (C 2 H 2) and 180 ° C, indicating great promise as a non- mercury catalyst for PVC manufacture.