Preparation And Aromatization Activity Of Tungsten Containing Catalysts

The catalytic conversion of light hydrocarbons to desired chemical products or liquid fuel is not only a promising approach for the utilization of light hydrocarbons resource but also a great challenge to catalysis science.Tungsten oxide?WO_x?is an inorganic non-noble metal materials with lower cost.It is considered to be a promising catalyst for the excellent catalytic performance.WO_x/HZSM-5 catalyst with high aromatization activity was prepared by hydrothermal method.The prepared catalyst was characterized by X-ray diffraction?XRD?,scanning electron microscope?SEM?,Energy Dispersive Spectrometer?EDS?,Fourier transform infrared spectroscopy?FT-IR?and Thermogravimetric Analysis?TG?.The results indicated that the WO_x is uniformly distributed on the surface of HZSM-5 and WO_x/HZSM-5 had the higher catalytic activity than WO₃/HZSM-5.WO_x/HZSM-5 also showed enhanced yield and selectivity of aromatics comparing with WO₃/HZSM-5 and HZSM-5 due to the more active sites in WO_x/HZSM-5 during the reduction process.Moreover,the resistance to carbon deposition and cracking capacity have been significantly improved.The best prepared condition is:180?,the concentration of WCl₆ is 0.01g/mL.the best WO_x content is 5.0%wt,weight hourly space velocity is 3.2h^-1.Under the reaction condition of WHSV=3.2h^-1,T=550?,the conversion of n-hexane is 99.6%,selectivity of aromatics is31.2%,yielding of aromatics is 31.1%?...