分子筛载体对Pt-Sn-Na三组分丙烷脱氢催化剂性能的影响

Effect of Zeolite Support on Catalytic Performance of Pt-Sn-Na Catalyst for Propane Dehydrogenation

采用等体积分步浸渍法,分别以不同n(SiO_2):n(Al_2O_3)的ZSM-5和β分子筛以及以一定比例机械混合的ZSM-5和β分子筛为载体,制备负载型Pt-Sn-Na三组分丙烷脱氢催化剂,在固定床微型反应装置上对制备的催化剂进行了丙烷脱氢性能评价,并采用NH_3-TPD方法对催化剂进行了表征。实验结果表明,以n(SiO_2):n(Al_2O_3)=100的ZSM-5分子筛和n(SiO_2):n(Al_2O_3)=80的β分子筛进行机械混合得到的混合分子筛为载体,制备的Pt-Sn-Na/ZSM-5-β催化剂的丙烷脱氢性能较好,在n(H_2):n(C_3H_8)=1:1、C_3H_8的重时空速2 h^(-1)、反应压力0.1 MPa、反应温度600℃的条件下,丙烷转化率约为28.0%,丙烯选择性大于等于98.6%。

Several platinum-tin-sodium catalysts different supports, namely ZSM-5 zeolite, β zeolite for propane dehydrogenation were prepared on and ZSM-5-β with different mass ratio prepared by mechanical mixing, and characterized by means of NH3-TPD. The effects of the zeolite type and n（SiO2） ： n（Al2O3） on the performances of the Pt-Sn-Na catalysts were studied in a fixed bed microreactor. The experimental results showed that the catalyst on the ZSM-5-β support, in which n（SiO2） ： n（Al2O3）s of ZSM-5 and β were 100 and 80 respectively, was excellent in the propane dehydrogenation process. Under the reaction conditions of n（H2） ： n（C3H8） 1 ： 1, C3H8 WHSV 2 h1, 0.1 MPa and 600℃, the propane conversion and selectivity to propylene are about 28.0% and 98.6%, respectively.