Binuclear　iron　clusters　were　constructed　successfully　in　cavities　of　HY　Zeolite　by　surface　organometallic　chemistry　(SOMC)　of　ferrocene.　UV-visible　diffuse　reflection　(UV-vis　DRS),　X-ray　absorption　fine　structure　(XAFS),　electron　paramagnetic　resonance　(EPR),　and　infrared　(IR)　spectroscopies　were　used　to　characterize　the　structure　of　the　formed　binuclear　iron　clusters.　The　results　show　that　the　majority　is　presented　as　binuclear　p-hydroxo-bridged　iron　clusters　consisting　of　a　[Fe-III(mu-OH)-Fe-III]　core,　which　is　anchored　on　the　zeolite　framework　by　the　bonding　of　Fe　atom　and　bridging　0　sites　that　lie　in　a　plane　of　a　12-membered　ring　connecting　the　supercages.　These　binuclear　iron　clusters　show　better　catalytic　reactivity　towards　phenol　hydroxylation　than　large　iron　oxide　clusters.　Iron　oxide　as　active　component　was　found　to　represent　a　nuclearity-related　catalytic　behavior　for　phenol　hydroxylation.　The　decrease　in　nuclearity　of　iron　oxides　from　nanoparticles　to　binuclear　iron　clusters　leads　to　the　increase　in　conversion　and　to　the　drastic　decrease　in　induction　time.　(C)　2009　Elsevier　Inc.　All　rights　reserved.