Abstract:

Supported gold catalysts were prepared by incipient wetness impregnation method using chloroauric acid as precursor and active carbon with different pore structure as supports. The catalytic performance was investigated for acetylene hydrochlorination. It was found that the catalytic activity was remarkably influenced by the pore structure of support. Catalyst on a support with a proper micropore size exhibited a superior activity and selectivity for vinyl chloride，and that on a support with a smaller micropore size exhibited a lower activity，which is probably due to the diffusion hindrance. While，the catalyst on a support with full mesopores showed a medium activity and low selectivity for vinyl chloride，dichloroethane was observed in the product. The optimum reaction temperature of the three catalysts was lower than 160℃，but the catalyst stability was inferior. The conversion of acetylene decreased dramatically with running time and was less than 10% in 400 min for all the three catalysts. TPR results showed that the Au³⁺ in the catalyst has close relation to the catalytic activity. Inductively coupled plasma atomic emission spectrometry（ICP-AES）was used to measure the gold content in the catalyst. Nitrogen adsorption-desorption method was used to investigate the specific surface area（BET area）and pore structure of the catalyst. Transmitted electronic microscopy（TEM）was used to observe the morphology of the catalyst samples.