nMoOx·HZSM-5催化正丁烷裂解增产丙烯性能研究

采用等体积浸渍法制备了nMoO_x·HZSM-5系列单相复合体，用XRD、NH₃-TPD、Py-FTIR、BET、SEM等技术对其物相结构、表面酸性、比表面积进行了表征。在连续固定床微反装置中对nMoO_x·HZSM-5单相复合体进行了催化正丁烷裂解性能的评价。结果表明，部分活性组分Mo以MoO_x原子簇的形式定位于HZSM-5分子筛的Z形和直形孔道交叉孔处，与分子筛的骨架氧配位形成nMoO_x·HZSM-5单相复合体，引起分子筛的骨架收缩，相应的晶胞参数及晶胞体积减小，比表面积下降；随Mo用量的增大，nMoO_x·HZSM-5单相复合体的酸量呈先增加后减小趋势；在反应温度625℃，体积空速5600 h^-1条件下，Mo用量为0.75%制备的nMoO_x·HZSM-5-0.75%单相复合体催化正丁烷裂解反应的转化率为73.83%，略低于HZSM-5分子筛，但丙烯收率却达到了13.13%，较HZSM-5分子筛提高2个百分点以上，表现出较好的增产丙烯效果。

Study on n-butane catalytic cracking for promoting propylene production over nMoOx·HZSM-5

A series of nMoO_x·HZSM-5 single-phase complexes were prepared by incipient wetness impregnation, and characterized by XRD, NH₃-TPD, Py-FTIR, BET and SEM techniques. The n-butane catalytic cracking performance over nMoO_x·HZSM-5 was investigated by using a continuous flowing micro reactor. The results indicate that active component Mo is located in the cross of Z form channel and straight channel of HZSM-5 in the form of MoO_x clusters to generate a nMoO_x·HZSM-5 single-phase complex, causing the contraction of HZSM-5 lattice cell and the reduction in the lattice parameters and cell volume of HZSM-5 as well as the decrease in specific surface area of HZSM-5. The acidity of nMoO_x·HZSM-5 shows an increases firstly and then a decrease with the increasing dosage of active component Mo. The n-butane catalytic cracking conversion over nMoO_x·HZSM-5-0.75% is 73.83% at reaction temperature of 625℃ and gas space velocity of 5600 h^-1, slightly lower than that over HZSM-5. However, the propylene yield over nMoO_x·HZSM-5-0.75% reaches 13.13%, 2 percent points higher than that over HZSM-5,exhibiting a better performance on the promotion of propylene yield.