甲醇制丙烯反应中磷改性对HZSM-5催化剂的影响

Effect of P-Modification of HZSM-5 Catalyst on the Methanol to Propylene Process

通过等体积浸渍法制备P改性HZSM-5催化剂，考察了不同程度的P改性对HZSM-5催化剂表征及催化性能的影响。实验结果表明，P改性后的催化剂的强酸位明显减弱，弱酸位有所增强。在P质量分数为0％～0．500％的范围内进行改性时，随着P质量分数的增加，P-HZSM-5催化剂的比表面积、微孔体积逐渐变小，平均孔径增大。但催化剂骨架结构保持不变，结晶度几乎不发生改变。相对于 P改性之前，催化剂的稳定性有了显著的提高，丙烯的选择性明显增加。且当P的质量分数为0．250％时，丙烯选择性最高可达54．6％。

P-modified HZSM-5 catalysts were prepared by impregnation and used in the reaction of methanol to propylene as the catalyst .The effect of different phosphorous precursor amount on their catalyst characterization and catalytic performance is investigated .The results show that the amount of strong acid sites of phosphorus modified catalysts decreased ,while that of weak acid sites increased .The increase of Ploading with the range of 0% and 0 .5% leads to the decrease of specific surface area and micropore volume ,the increase of average pore size as well .However ,there is no change in the framework and crystallinity .Compared with HZSM-5 ,the stability of P/HZSM-5 catalyst has been significantly improved ,and the selectivity to propylene was significantly increased .And when the mass fraction of Pis 0 .25% ,Propylene selectivity could be up to 54 . 6% .