Pt/γ‐Al₂O₃ Catalyst for Liquid‐Phase Hydrogen‐Transfer Hydrodechlorination of 4‐Chlorophenol in Alkaline Isopropanol

Abstract

The mild catalytic hydrogen‐transfer hydrodechlorination (HDC) of 4‐chlorophenol (4‐CP) was studied in heterogeneous batch mode. The applied catalyst was prepared by impregnation of γ‐Al2O3 with preformed Pt nanoparticles (1.0 % w/w). Analytical data of both the Pt nanoparticles and the final catalyst are presented. 96.8 % conversion of 4‐chlorophenol was obtained in isopropanol after 24 h at 82 °C and atmospheric pressure in the presence of potassium tert‐butoxide (tBuOK). Phenol was the only reaction product formed and hydrogenation of the aromatic ring did not occur. The Pt/γ‐Al2O3 catalyst was also evaluated under varying reaction conditions (temperature, base, time) and it shows during 5 hydrodechlorination/regeneration cycles only slight deactivation (24 h at 82 °C, X=87.3 % after the fifth cycle).