Activation of molecular oxygen over binuclear iron centers in Al-rich BEA zeolite

• Published in: Applied catalysis. B, Environmental Vol. 336; p. 122915
• Main Authors: Kornas, Agnieszka, Tabor, Edyta, Wierzbicki, Dominik K., Olszowka, Joanna E., Pilar, Radim, Dedecek, Jiri, Sliwa, Michal, Jirglova, Hana, Sklenak, Stepan, Rutkowska-Zbik, Dorota, Mlekodaj, Kinga
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.11.2023
• Subjects: Al-rich BEA; Distant binuclear iron centers; Methane oxidation; Molecular oxygen splitting; Template-free synthesis; Distant binuclear iron centers; Template-free synthesis; Methane oxidation; Al-rich BEA; Molecular oxygen splitting
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2023.122915

Here, we present the unique redox properties of distant binuclear iron centers in Al-rich *BEA zeolite in O2 splitting and CH4 oxidation. Al-rich *BEA was obtained via a template-free synthesis procedure guaranteeing low-defected structure and a high fraction of Al-pairs enabling stabilization of binuclear iron centers. By employment of a multispectroscopic in-situ approach (Mössbauer and X-ray absorption) the formation of active oxygen over binuclear iron centers in Al-rich *BEA was confirmed and subsequent CH4 oxidation was studied. Spontaneous release of the reaction products to the gas stream, representing a significant advantage of the studied system, was proved by the results of in-situ FTIR and mass spectrometry. This is the first experimental proof of the formation of fully-functioned binuclear iron centers (able to split O2, stabilize active oxygen forms, and subsequently oxidize CH4) in zeolite of *BEA topology. [Display omitted] •Al-rich *BEA with high number of Al pairs was synthesized via template-free procedure.•Distant binuclear sites able to split molecular oxygen were prepared in *BEA zeolite.•Methane can be oxidized by molecular oxygen at low temperature over Fe-*BEA zeolite.•Methane oxidation products are released spontaneously from Fe-*BEA to the gas stream.