以硝酸铈、硝酸镧为前驱体，采用水热法合成不同La-Ce质量比改性的ZSM-5分子筛，运用分步浸渍法负载铂和钠制备不同载体的铂基催化剂，通过XRD、BET、NH₃-TPD、TG对催化剂进行表征。并以丙烷为原料在固定床反应器中脱氢，对不同催化剂进行评价，考察不同反应条件对催化剂性能的影响。结果表明：相对于单一的ZSM-5分子筛，在水热合成分子筛中引入适当质量比的La、Ce会使催化剂的比表面积、孔体积和孔径减小，分子筛的结晶度降低，但不改变分子筛原有的晶体结构，同时La、Ce的相互协同作用能降低催化剂的酸性，提高催化剂的抗积碳性能。在催化剂用量为2.0 g、反应压力为0.1 MPa、反应温度为590℃、氢烃摩尔比为0.25、质量空速为3 h^-1时，La、Ce质量比为0.75的PtNa/La-Ce-ZSM-5催化剂显示了最佳的催化活性，丙烷转化率为36.8%，丙烯的选择性为95.9%，并且反应40 h后仍具有良好的催化稳定性。

ZSM-5 molecular sieve with different mass ratios of La to Ce is synthesized by hydrothermal method using cerium nitrate and lanthanum nitrate as precursors.Platinum-based catalysts with different supporters are prepared by stepwise impregnation method through supporting platinum and sodium on the prepared ZSM-5 molecular sieve,and are characterized by XRD,BET,NH₃-TPD and TG.Catalytic performances of catalyst are evaluated in a fixed bed reactor by using propane as raw material to carry out dehydrogenation.The effects of different reaction conditions on the performance of catalysts are investigated.The results show that the appropriate addition of lanthanum and cerium in ZSM-5 molecular sieve can lead to drops of specific surface area,pore volume and pore size of as-prepared catalysts,and can reduce the crystallinity of as-prepared molecular sieve compared with pure ZSM-5 molecular sieve but has not impact on the original crystal structure of molecular sieve.The PtNa/La-Ce-ZSM-5 catalyst with mass ratio of La to Ce at 0.75 shows the best catalytic activity when the catalyst dosage is 2.0 g,reaction pressure is 0.1 MPa,reaction temperature is 590℃,the molar ratio between hydrogen and hydrocarbon is 0.25 and the mass space velocity is 3 h^-1.Meanwhile,the conversion of propane is 36.8% and the selectivity of propylene is 95.9%.The catalyst remains good catalytic stability after 40 h of reaction.

陈利利(1992-),女,硕士研究生,研究方向为脱氢催化,1204813356@qq.com