Pt-SDB疏水催化剂的粒径效应

制备了三种不同粒径的Pt-聚苯乙烯-二乙烯基苯(SDB)催化剂(1.0、2.0、4.0mm),并对比研究了三种催化剂的水-氢交换反应性能。研究表明:同一工艺条件下制备的催化剂,催化反应的同位素交换效率随着粒径的增大而降低,催化剂的粒径效应明显;为了减小粒径效应,优化了催化剂的还原温度,当粒径从1.0mm增至4.0mm时,催化剂的最优还原温度从240℃升高到320℃;进一步结合程序升温还原的方法,分析了还原反应的活化能,发现随着粒径的增大,最优还原温度的升高可能是改善了还原过程中的热量与质量传递。

Exploring Size Effect of Pt-SDB Hydrophobic Catalysts

In this study, the catalysts with three kinds of particle size (1.0 mm, 2.0 mm and 4.0 mm) were fabricated to explore the size effect for hydrogen isotopes separation. It is found that the performance of the catalysts significantly decreases with the increasing size of the particles prepared using the same process. Furthermore, the optimal reduction temperature was identified for three kinds of catalysts to decrease the size effect. When the particle sizes increase from 1.0 mm to 4.0 mm, the reduction temperatures increase from 240 ℃ to 320 ℃. In addition, the TPR (temperature programmed reduction) approach was deployed to investigate the underlying mechanism for the effect of reduction temperature. The results indicate that the higher reduction temperature maybe improve the transfer of heat and mass during the reduction process.