磷的引入对Zn-ZSM-5催化剂甲醇芳构化性能的影响

Phosphorous modified Zn-ZSM-5 catalysts for methanol aromatization

在锌改性ZSM-5分子筛的基础上引入第二组分磷,以调变分子筛的酸性和择形性能,并对催化剂的甲醇芳构化性能进行评价。采用氨程序升温脱附、N2低温吸附-脱附、X射线衍射等对催化剂进行表征。结果表明,添加磷物种后催化剂的水热稳定性明显提升,磷改善分子筛表面酸中心强度和分布,提高了催化剂的轻质芳烃选择性。P/Zn-ZSM-5分子筛催化剂在压力0. 1 MPa、反应时间240 min、空速0. 8 h-1和反应温度437℃的条件下,BTX收率为40. 29%,具有较高的芳烃收率和反应稳定性。

Acidity and shape selectivity of Zn-ZSM-5 catalysts were modified by phosphorous.Physicochemical properties of these catalysts were appropriately characterized by N 2 isothermal adsorption-desorption,NH 3 temperature-programmed desorption,powder X-ray diffraction.Results showed that P/Zn-ZSM-5 catalysts had better hydrothermal stability.Acid strength and distribution on zeolite surface were improved by P modification,so as to increase selectivity of light aromatics.Aromatics yield of 40.29%was attained under the condition of reaction pressure 0.1 MPa,space velocity 0.8 h-1,reaction temperature 437℃,and reaction time 240 min.