【摘要】 利用硅油对HZSM-5分子筛进行液相沉积S iO2改性,制备了S iO2/HZSM-5催化剂(简称催化剂);考察了S iO2沉积量及反应条件对催化剂催化C4烯烃裂解生产丙烯性能的影响;采用X射线衍射、N2等温吸附-脱附、透射电子显微镜、扫描电子显微镜、吡啶吸附-脱附红外光谱等方法对催化剂进行了表征。实验结果表明,在HZSM-5分子筛上沉积SiO2调变了催化剂的孔结构和酸性,SiO2沉积量影响催化剂的性能,当SiO2沉积量为7.0%(质量分数)时,催化剂具有适当的孔结构和酸性,催化剂的性能较好。在530℃、0.1MPa、原料重时空速2.0 h-1、催化剂中SiO2沉积量7.0%的条件下,C4烯烃转化率为42.9%,丙烯收率为28.3%。更多还原

【Abstract】 HZSM-5 molecular sieve catalyst modified with SiO₂ was prepared by impregnation of HZSM-5 molecular sieve in liquid silicon oil.Activity of catalyst for catalytic cracking of C₄ olefins to propylene was evaluated in a mini-fixed-bed reactor.The catalyst was characterized by means of XRD,N₂ isothermal adsorption-desorption,TEM,SEM and Py-FTIR.Effects of SiO₂ deposition amount and reaction conditions on catalytic activity were investigated.When SiO₂ deposition amount is 7.0%（mass fraction）,activity of SiO₂/HZSM-5 catalyst is the best.Under optimal reaction conditions:530℃,0.1MPa and weight hourly space velocity 2.0h^-1,yield of propylene and conversion of C₄ olefins can reach 28.3% and 42.9%,respectively.The SiO₂ deposition on HZSM-5 molecular sieve modifies acidity and pore structure of catalyst,so activity of catalyst is improved.更多还原