摘要
Exo-tetrahydrodicyclopentadiene （exo-TCD） is an important high-energy fuel. Silicotungstic acid （SiW） immobilized on H-type β zeolite （Hβ） at room temperature were used to prepare the Hβ zeolite catalysts with different SiW contents. Catalytic performances of the catalysts were investigated during the preparation of exo-TCD via isomerization of endo-tetrahydrodicyclopentadiene （endo-TCD）. The properties of catalysts were characterized by XRD, temperature pro- grammed desorption of ammonia （NHa-TPD）, FT-IR, and N2-adsorption techniques. SiW was highly dispersed on the surface of Hβ zeolite, and the 10% SiW/Hβ zeolite catalyst had the highest amount of weak acidity among all SiW/Hβ zeolite catalysts. The influence of different factors on isomerization reaction was investigated. At a reaction temperature of 240 ℃, a n（cyclohexane） / n（endo-TCD） ratio of 10, a m（catalyst）/m（endo-TCD） ratio of 0.3, an initial pressure of 1.0 MPa, and a reaction time of 1.5 h in the presence of 10% SiW/Hβ catalyst calcined at 400 ℃, the conversion of endo-TCD reached up to 92.0%, with the yield of exo-TCD equating to 51.0%.
Exo-tetrahydrodicyclopentadiene (exo-TCD) is an important high-energy fuel.Silicotungstic acid (SiW) immobilized on H-type β zeolite (Hβ) at room temperature were used to prepare the Hβ zeolite catalysts with different SiW contents.Catalytic performances of the catalysts were investigated during the preparation of exo-TCD via isomerization of endo-tetrahydrodicyclopentadiene (endo-TCD).The properties of catalysts were characterized by XRD,temperature pro-grammed desorption of ammonia (NH 3-TPD),FT-IR,and N 2-adsorption techniques.SiW was highly dispersed on the surface of Hβ zeolite,and the 10% SiW/Hβ zeolite catalyst had the highest amount of weak acidity among all SiW/Hβ zeolite catalysts.The influence of different factors on isomerization reaction was investigated.At a reaction temperature of 240 ℃,a n(cyclohexane) /n(endo-TCD) ratio of 10,a m(catalyst) /m(endo-TCD) ratio of 0.3,an initial pressure of 1.0 MPa,and a reaction time of 1.5 h in the presence of 10% SiW/Hβ catalyst calcined at 400 ℃,the conversion of endo-TCD reached up to 92.0%,with the yield of exo-TCD equating to 51.0%.
