Gas phase hydrotreatment of chlorophenols over Pd catalysts as an alternative route to cyclohexanone

作者：Gomez Quero Santiago; Cardenas Lizana Fernando; Keane Mark A^*

来源：Reaction Kinetics, Mechanisms and Catalysis, 2016, 119(1): 35-48.

DOI：10.1007/s11144-016-1046-1

• Cyclohexanone
• Chlorophenol(s)
• Pd catalysts
• Coupled hydrodechlorination/hydrogenation

We have established viability of cyclohexanone (C6ONE) production via coupled gas phase (1 atm, 423 K) continuous hydrodechlorination/hydrogenation of mono- and di-chlorophenols over bulk Pd and Pd/Al2O3. The catalysts have been characterised by temperature programmed reduction (TPR), H-2 chemisorption, powder XRD and TEM analyses. Hydrodechlorination is not a thermodynamically limiting step where under catalytic control we achieve significantly greater C6ONE yields relative to those from standard phenol hydrogenation. We account for this response in terms of a direct chlorophenol -> C6ONE conversion facilitated by electron delocalisation in the intermediate generated via electrophilic hydrogen cleavage of C-Cl bond(s). The C6ONE selectivity/conversion profiles coincided for bulk and supported Pd and we demonstrate structure sensitivity for the production of C6ONE from 2,4-dichlorophenol with higher specific rates over larger Pd particles (2 -> 250 nm).

• 出版日期2016-10