Mild Oxidation of Methane to Oxygenates with O2 and CO on Fluorine Modified TS-1 Supported Rh Single-Atom Catalyst in a Flow Reactor

• Published in: Catalysis letters 2024, Vol.154 (1), p.259-269
• Main Authors: Wang, Honglin, Xin, Wenyu, Zheng, Xiangdong, Wang, Quan, Pei, Ruqin, Dong, Xianjiang
• Format: Article
• Language: English
• Subjects: acidity; Adsorbed water; Adsorption; Ammonia; Bond energy; Carbon monoxide; Catalysis; catalysts; Catalytic activity; Catalytic converters; Chemistry; Chemistry and Materials Science; Continuous flow; energy; Fixed beds; Fluorine; hydrophilicity; Hydrophobicity; Industrial Chemistry/Chemical Engineering; liquids; Low pressure; Methane; Organometallic Chemistry; Oxidation; Physical Chemistry; pyridines; Rhodium; Single atom catalysts
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-023-04298-y

Direct catalytic conversion of methane to liquid oxygenates under mild conditions remains a challenge due to high bond energy of symmetric CH 4 . Isolated Rh atoms were supported on hydrophobic fluorine modified TS-1 (FTS-1). Single-atom Rh on FTS-1 catalyst was characterized with Ac-HAADF/STEM and CO adsorption FTIR. The aerobic selective conversion of methane to oxygenates was carried out in a fixed bed continuous flow reactor upon co-feeding CO and H 2 O at 423 K under relative low pressure (42.3 kPa CH 4 , 21.1 kPa CO, 10.6 kPa O 2 , 0.476 MPa H 2 O). Hydrophobic Rh/FTS-1 catalyst exhibits higher activity (151.9 mol products /(mol metal h)) than the activity (36.4 mol products /(mol metal h)) over hydrophilic Rh-ZSM-5 (Si/Al = 15) under such reaction conditions. Hydrophobicity of different catalysts were compared by water adsorption test. The catalytic activity of F modified TS-1 supported single-atom Rh (Rh/FTS-1) is higher than that of unmodified Rh/TS-1 which is due to its higher Lewis acidity as shown by pyridine adsorption FTIR and NH 3 -TPD. Graphical Abstract