Preparation of Adamantane over Complex Catalysts PW/USY

In a 100 mL stirred batch stainless-steel autoclave,the catalytic performances of 12-tungstophosphoric acid(PW)immobilized on ultrastable Y zeolite(USY)used for preparing adamantane(ADH)by isomerization of endo-tetrahydrodicyclotadiene(endo-TCD)were investigated.The physical chemical properties of catalysts PW/USY were characterized by X-ray diffraction(XRD),temperature programmed desorption of ammonia(NH3-TPD)and FT-IR.It was found that,both the acidity and pore structure of the zeolite are the key factors influencing the catalytic behavior,and the catalyst PW/USY with 10%(wt)PW loading(10%PW/USY)has the largest acid amount.The influences of reaction conditions on the catalytic isomerization of endo-TCD were evaluated with 10%PW/USY catalyst.The conversion of endo-TCD up to 99.5% and the yield of adamantane up to 28.3% can be achieved when the reaction conditions are as follows:calcination temperature of 10%PW/USY catalyst is 450℃,reaction temperature is 260℃,n(cyclohexane)/n(endo-TCD)=5,w(catalyst)/w(endo-TCD)=0.2,initial pressure is 0.8MPa and reaction time is 6 h.