Photo-Driven Aerobic Methane Nitration

Xuefeng He; Lina Zhang; Jiawei Chen; Huichong Liu; Yuming Su; Han Li; Yonghua Cao; Pavlo O Dral; Cheng Wang

doi:10.1021/acs.inorgchem.3c01210

Photo-Driven Aerobic Methane Nitration

Inorg Chem. 2023 Jul 3;62(26):10343-10350. doi: 10.1021/acs.inorgchem.3c01210. Epub 2023 Jun 21.

Authors

Xuefeng He¹, Lina Zhang¹, Jiawei Chen¹, Huichong Liu¹, Yuming Su¹, Han Li¹, Yonghua Cao¹, Pavlo O Dral^{1

2

3}, Cheng Wang^{1

2}

Affiliations

¹ State Key Laboratory of Physical Chemistry of Solid Surfaces, iChem, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
² Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, P. R. China.
³ Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen University, Xiamen 361005, P. R. China.

PMID: 37341569
DOI: 10.1021/acs.inorgchem.3c01210

Abstract

Conversion of methane to liquid oxygenates is challenging but of great value. Here, we report the oxidation of methane (CH₄) to methanol (CH₃OH) assisted by nitrogen dioxide (NO₂) as a photo-mediator and using molecular oxygen (O₂) as the terminal oxidant. Similar photoreactions are widely studied in atmospheric chemistry but were not previously used in preparative methane conversion. We used visible light to excite NO₂ generated by heating aluminum nitrate Al(NO₃)₃ and drove its reaction with methane and O₂ to produce methyl nitrate (CH₃ONO₂), which is then hydrolyzed to CH₃OH. Nitric acid (HNO₃) and nitrate (NO₃^-) were produced and recycled back to Al(NO₃)₃, completing a chemical loop. HCl can catalyze this photochemical process via relay hydrogen atom-transfer reactions, with up to 17% methane conversion and 78% CH₃ONO₂ selectivity. This simple photochemical system provides new opportunities in selective methane transformation.