Trinuclear　Fe　(III)　acetato　complex　intercalated　montmorillonite　Fenton　catalysts　with　large　surface　areas　were　prepared　by　a　facile　ion　exchange　process.　The　obtained　samples　were　characterized　by　FT-IR,　TGA-DSC,　N-2-sorption　and　XPS　in　detail.　To　understand　the　microstructure　of　the　active　iron　species　in　the　montmorillonite,　the　Fe　K-edge　X-ray　absorption　spectra　(XAFS)　technique　was　also　employed.　The　results　showed　that　the　trinuclear　iron　cluster　was　successfully　intercalated　into　the　layers　of　montmorillonite　and　the　structure　of　the　active　iron　species　was　an　amorphous　FeO(OH)-like　structure　after　500　degrees　C　post-treatment.　When　the　prepared　catalysts　were　used　for　the　photo-Fenton　reaction　at　room　temperature,　excellent　activities　were　observed　for　degradation　of　phenol.　Moreover,　their　activities　were　much　higher　than　those　of　the　traditional　iron　hydroxyl　compound　intercalated　montmoillonite　Fenton　catalyst.　The　stable　intercalated　structure　and　the　low　leaching　Fe　concentration　induced　that　the　obtained　catalyst　can　be　operated　for　a　long　time.　Meanwhile,　the　consumption　of　H2O2　and　the　change　of　pH　in　solution　were　also　investigated　in　detail.　(C)　2011　Elsevier　B.V.　All　rights　reserved.