The phenol hydroxylation catalyzed over copper-containing pentatomic hydrotalcite (Cu-PHTL) is investigated during the catalyst cycle lifetime. The results show the fresh catalyst exhibits very high initial activity for the reaction. However, the rapid deactivation of catalyst is observed after the fifth operation. The cause of catalyst deactivation is discussed according to the characterizations of ICP-AES, XRD, FT-IR, TEM and XPS, which is mainly attributed to carbon deposit on the surface of the catalyst. Moreover, the deactivated catalyst is easily reactivated by burning deposited carbon in air and then washing with acetone, and the reactivated catalyst shows catalytic activity as almost high as the fresh sample. However, a small difference in catalytic activities between reactivated and fresh catalysts is possibly owing to the slight Cu leaching. (c) 2006 Elsevier B.V. All rights reserved.