Efficient Photo-Assisted Thermal Selective Oxidation of Toluene Using N-Doped TiO2

Cheng Chen; Mingge Wu; Chunyan Ma; Maoyong Song; Guibin Jiang

doi:10.1021/acsomega.3c01887

Efficient Photo-Assisted Thermal Selective Oxidation of Toluene Using N-Doped TiO₂

ACS Omega. 2023 May 30;8(23):21026-21031. doi: 10.1021/acsomega.3c01887. eCollection 2023 Jun 13.

Authors

Cheng Chen^{1

2}, Mingge Wu³, Chunyan Ma¹, Maoyong Song^{1

2

4}, Guibin Jiang^{2

4}

Affiliations

¹ Key Laboratory of Environmental Nanotechnology and Health Effects, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.
³ Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
⁴ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.

Abstract

Selective oxidation of toluene is a key reaction to produce high value-added products but remains a big challenge. In this study, we introduce a nitrogen-doped TiO₂ (N-TiO₂) catalyst to create more Ti³⁺ and oxygen vacancy (O_V), which act as active sites for selective oxidation of toluene via activating O₂ to superoxide radical (•O₂^-). Interestingly, the resulting N-TiO₂-2 exhibited an outstanding photo-assisted thermal performance with a product yield of 209.6 mmol·g_cat^-1 and a toluene conversion of 10960.0 μmol·g_cat^-1·h^-1, which are 1.6 and 1.8 times greater than those obtained under thermal catalysis. We showed that the enhanced performance under photo-assisted thermal catalysis was attributed to more active species generation by making full use of photogenerated carriers. Our work suggests a viewpoint to apply a noble-metal-free TiO₂ system in the selective oxidation of toluene under solvent-free conditions.