K2WO4/Al2O3 catalysts for methanethiol synthesis from methanol and H2S: effect of catalyst preparation procedure

摘要

A series of the K2WO4/gamma-Al2O3 catalysts was prepared with different introducing strategy of the K2WO4 to alumina and characterized by means of N-2 adsorption-desorption, XRD, XPS, CO2/NH3-TPD, H-2-TPR. It was found that the different introduction strategy of K2WO4 did not change the valence state of surface species of the catalysts but markedly influenced the structures, dispersion of tungsten and potassium species and acid-basic properties. The catalysts prepared by the sol-gel precipitation method exhibit larger surface area, better dispersion of the W species and more favorable acid-basic properties, thus possess higher activity for the reaction, particularly, at the lower reaction temperature of 320 degrees C, the methanethiol yield was about 8.3% higher than that over the catalyst prepared by traditional impregnation method. As a model catalyst, the catalysts prepared by sol-gel precipitation method show a higher and more stable reactivity with small dosage of water and CS2, and worth in industrial application.