Catalytic hydrodechlorination (HDC) of 4-chlorophenol (4-CP) was studied using catalysts based on Al-pillared clays containing Rh. The Rh-Al pillared clays synthesized showed highly stable and no Rh leaching was detected. Two different hydrogen sources were used for this reaction with fairly different results. When using hydrogen gas, complete 4-CP removal was achieved even at mild operating conditions (25 degrees C, atmospheric pressure). The use of formic acid led to substantially lower conversion (65%) for equivalent reaction time, even when the reaction temperature was increased to 90 degrees C. The influence of Rh load and reaction temperature on the catalytic activity of Rh-Al pillared clays was checked. The stability of the catalyst was tested in repeated consecutive runs. A progressive increase of the catalytic activity was found up to the third reaction cycle due to the successive reduction of the metallic phase of the catalyst. After that, a decrease of activity was observed, probably due to the damage of the microporous structure. (C) 2010 Elsevier B.V. All rights reserved.