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本文以质谱仪为检测器的热脱附动力学方法测定了高温水蒸汽处理及磷、镁、硼浸渍改性HZSM-5沸石上甲醉的扩散活化能(E_d)及与沸石有效孔径有关的指数前因子(D_o)。结果表明,改性会使沸石的有效孔径缩小,其孔径大小的次序为:HZSM-5>HZSM-5-400>HZSM-5-600>PZSM-5(2％)>PZSM-5(4%)>MgYZSM-5(3％)>BZSM-5(3％)>BZSM-5(5％)。与用 NH_3-TPD及IR所测得的改性沸石表面酸性质相比,沸石的有效孔径的因素对甲醇转化反应中低碳烯烃选择性的影响小于沸石表面B酸量和酸强度的因素。
In this paper, the thermal desorption kinetics of mass spectrometer was used to determine the activation energy (E_d) and the effective pore size of zeolite modified by high temperature steam treatment and phosphorus, magnesium and boron impregnated HZSM-5 zeolites Exponential factor (D_o). The results showed that the modified zeolite could reduce the effective pore size of zeolite. The order of pore size was HZSM-5> HZSM-5-400> HZSM-5-600> PZSM-5 (2% )> MgYZSM-5 (3%)> BZSM-5 (3%)> BZSM-5 (5%). The effect of the zeolite effective pore size on the selectivity to light olefins in the methanol conversion reaction is less than that of zeolite B acid content and acid strength, as compared to the surface acid properties of modified zeolites measured with NH_3-TPD and IR.