Splitting Dioxygen over Distant Binuclear Fe Sites in Zeolites. Effect of the Local Arrangement and Framework Topology

0539845 - ÚFCH JH 2022 RIV US eng J - Journal Article
Tabor, Edyta - Lemishka, Mariia - Olszówka, Joanna Elżbieta - Mlekodaj, Kinga - Dědeček, Jiří - Andrikopoulos, Prokopis C. - Sklenák, Štěpán
Splitting Dioxygen over Distant Binuclear Fe Sites in Zeolites. Effect of the Local Arrangement and Framework Topology.
ACS Catalysis. Roč. 11, č. 4 (2021), s. 2340-2355. ISSN 2155-5435. E-ISSN 2155-5435
R&D Projects: GA ČR(CZ) GA17-00742S
Institutional support: RVO:61388955
Keywords : alpha oxygen * oxidation of methane * utilization of methane
OECD category: Physical chemistry
Impact factor: 13.700, year: 2021
Method of publishing: Limited access

Activation of dioxygen is of extreme importance due to its potential for transformation of methane to valuable products and applications in other selective oxidation reactions. Distant binuclear cationic Fe(II) centers in Fe-ferrierite were shown to split dioxygen at room temperature to form a pair of very active oxygen species (i.e., α-oxygens) and subsequently oxidize methane to methanol at room temperature as well. Our study reveals that the activity in splitting dioxygen represents a general property of the distant binuclear cationic Fe(II) centers stabilized in the aluminosilicate matrix. Computational models of the ferrierite, beta, A, and mordenite zeolites with various Al sitings in the rings forming the cationic sites were investigated by periodic DFT calculations including molecular dynamics simulations. The results reveal that the Fe(II) sites stabilized in various zeolite matrices can split dioxygen if the two cationic sites forming the distant binuclear Fe(II) centers (i) face each other, (ii) are parallel, and (iii) are axial, and (iv) the Fe···Fe distance lies in a narrow range from ca. 7 to ca. 8 Å (ca. 7–ca. 10 Å for the distance between the two rings (forming the corresponding cationic sites) in empty zeolites since this distance is equal to or larger than the Fe···Fe distances). Our study opens the possibility of developing Fe-zeolite-based systems for the dioxygen activation employed for direct oxidations using various zeolite matrices.
Permanent Link: http://hdl.handle.net/11104/0317547