Hydrodechlorination of 4-chlorophenol in aqueous phase with Pt-Al pillared clays using formic acid as hydrogen source

摘要

Catalysts based on pillared clays with Al and Pt were synthesized from a commercial bentonite and tested for catalytic hydrodechlorination (HDC) using 4-chlorophenol (4-CPhOH) as the target compound and formic acid as the hydrogen source. Stable Pt-Al pillared clays were obtained, showing a high activity and a strong fixation of the active phase to the support. The influence of the method of introduction of Pt in the pillared clay (ion-exchange or impregnation) and the Pt content in the catalytic activity was checked. Likewise, operating variables such as reaction temperature, catalyst concentration and formic acid to 4-CPhOH molar ratio were studied; higher values of these variables gave rise to a higher 4-CPhOH conversion to phenol. An important deactivation of the catalyst was observed, probably due to the formation of carboneous deposits since no appreciable Pt leaching was detected.