Catalytic Performance of PW/Meso-H-Mordenite Zeolite in Preparation of Adamantane

Desilicated mesoporous H-mordenite(0.20)(HM(0.20))was prepared through treatment of H-mordenite including template tetraethylammonium hydroxide(TEAOH)with NaOH aqueous solution.12-Tungstophosphoric acid(PW)was immobilized on the desilicated mesoporous HM(0.20)by excessive immersion method at room temperature to form the PW/HM(0.20) catalysts with different PW loadings.The physical chemical properties of these catalysts were characterized by X-ray diffraction(XRD),N2 adsorption-desorption and ammonia program temperature desorption(NH3-TPD)techniques,and their catalytic performances were investigated in the preparation of adamantane(ADH)by isomerization of endo-tetrahydrodicyclotadiene(endo-TCD) in a 100mL stainless steel batch reactor equipped with a stirrer.The results showed that mesopores could be introduced into the structure of H-mordenite by treating with NaOH aqueous solution.The loaded PW could still be highly dispersed on the surface of the HM(0.20)zeolite when the PW loading was as high as 30%.The 20%PW/HM(0.20)catalyst showed a higher catalytic activity in ADH preparation rather than other employed catalysts because of its highest acid amount.The conversion of endo-TCD 98.9% and the yield of ADH 32.3% were obtained under the reaction conditions of reaction temperature 260℃,w(Catalyst)/w(endo-TCD)0.5,reaction time 6h.The catalytic activity of used catalyst could be recovered and the yield of ADH reached 27.4% after 5times reuse.