用硅修饰不同酸性的 HZSM-5、PZSM-5和 BiZSM-5沸石催化剂,发现随硅添加量增加,基质的总酸量减少,B 酸和 L 酸中心同时被覆盖,甲苯的乙基化活性下降,对位选择性升高。当加硅至7.2%时,它们各自提高10%、11%和43%。论述了影响选择性的因素,得出在孔内具有中等酸强度的酸中心是提高对位选择性和稳定性的重要条件之一。 Modification of zeolites with different acidic HZSM-5, PZSM-5 and BiZSM-5 zeolites showed that with the increase of the amount of silicon added, the total acidity of the matrix decreased, the B acid and L acid centers were covered simultaneously, and the ethylation activity of toluene Decline, the selective increase. When silicon was added to 7.2%, they each increased by 10%, 11% and 43%. The factors influencing the selectivity are discussed. It is concluded that the acid sites with moderate acid strength in the pores are one of the important conditions to improve the para-selectivity and stability.