Y分子筛负载V基催化剂的丙烷氧化脱氢性能

Oxidative dehydrogenation of propane over vanadium based catalysts supported on Y molecular sieve

以Y分子筛为载体,采用浸渍法制备不同V含量的V/Y系列催化剂,并考察其丙烷氧化脱氢制丙烯的催化性能。通过BET、XRD、H_2-TPR和NH_3-TPD等技术对催化剂的物化性能进行表征。结果表明,Y分子筛具有大比表面积和窄孔径分布的特点,使负载的V能够形成高分散和孤立态V—O物种,负载的V物种堵塞了Y分子筛的小孔孔道,同时Y分子筛的弱酸性位有助于丙烷的吸附,对晶格氧活化丙烷起到了协同作用,负载V质量分数6%时,催化效果最好。

Using Y molecular sieve as the support,vanadium supported Y molecular sieve catalysts （V/Y） with different vanadium contents were prepared by the impregnation method, and their catalytic perform- ance in the oxidative dehydrogenation of propane to propene was investigated. The catalysts were charac- terized by BET, XRD, H2-TPR and NH3-TPD. The results showed that Y molecular sieve possessed large specific surface area and narrow pore size distribution, which enabled vanadium to form highly dispersed and isolated state V--O species;the loading vanadium species blocked the small pore channels of Y molecular sieve ; at the same time, the weak acid sites of Y molecular sieve was helpful to propane adsorp- tion, and had synergistic effect on propane activation by lattice oxygen. V/Y catalyst with 6wt% vanadium exhibited better catalytic performance.