【摘要】 采用氨程序升温脱附技术考察了焙烧和水热处理后HZSM-5沸石的表面酸性,研究了处理温度对nc₇^?和C₃^-转化反应的影响以及对沸石择形性的影响。实验表明:高温焙烧和水热处理可除去HZSM-5沸石表面的部份强酸中心,使nC₇^?和C₃^-转化反应的活性降低,产物中汽油收率达到最大值,但芳烃收率有所降低,二甲苯异构体中对二甲苯的选择性显若提高。更多还原

【Abstract】 The effect of calcination and hydrothermal treatment on the surface acid properties of HZSM-5 zeolite has been investigated by NH₃ TPD. the shape selectivity and activity for propylene and n-heptane over HZSM-5 zeolite have been determined by pulsed-chromatographic technique. The results revealed that the strong acid sites and catalytic, activity of HZSM-5 zeolite decreased with the raising of treatment temperature, The maximum yield of gasoline in the product was obtained and the selectivity for p-isomer in xylene isomerization was increased remarkably at the calcination temperature of 750℃ and the hydrothermal temperature of 500℃, but the yield of aromatics was decreased.更多还原