Water pollution derived from organic pollutants is one of the global environmental problems. The Fenton reaction using Fe 2 + as a homogeneous catalyst has been known as one of clean methods for oxidative degradation of organic pollutants. Here, a layered double hydroxide (Fe 2 + Al 3 + -LDH) containing Fe 2 + and Al 3 + in the structure was used to develop a "heterogeneous" Fenton catalyst capable of mineralizing organic pollutants. We found that sulfate ion (SO 4 2À ) immobilized on the Fe 2 + Al 3 + -LDH significantly facilitated oxidative degradation (mineralization) of phenol as a model compound of water pollutants to carbon dioxide (CO 2 ) in a heterogeneous Fenton process. The phenol conversion and mineralization efficiency to CO 2 reached > 99% and ca. 50%, respectively, even with a reaction time of only 60 min.