Main content area

Liquid phase hydrodechlorination of chlorophenols at lower temperature on a novel Pd catalyst

Jin, Zhonghao, Yu, Chao, Wang, Xingyi, Wan, Ying, Li, Dao, Lu, Guanzhong
Journal of hazardous materials 2011 v.186 no.2-3 pp. 1726-1732
2,4-dichlorophenol, 2-chlorophenol, X-ray diffraction, catalysts, hydrogen, nanoparticles, solvents, temperature, transmission electron microscopy, triethylamine
Pd catalyst supported on mesoporous silica–carbon nano-composite (Pd/MSCN) was prepared by the method of wet impregnation, and its activity for hydrodechlorination (HDC) of 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol was evaluated at 258–313K under ordinary hydrogen pressure by using triethylamine (Et₃N) as a base additive. XRD analysis indicates that Pd/MSCN catalyst possesses the ordered mesostructure. Meanwhile, the results from TEM and H₂ chemisorption analysis indicate the high dispersion of Pd on MSCN with Pd nanoparticles whose average size is 3.2nm. For the first time, the high activity of nano-size Pd on MSCN for HDC of chlorophenols was observed at 258K. In addition, it was found that the inhibition effect of Et₃N on HDC existed obviously, and can be efficiently reduced by stepwise addition of Et₃N. The correlations of the dielectric constants of base and the polarity of solvent to the activity of Pd/MSCN for HDC of chlorophenols were obtained.