Catalytic decomposition of NO2 over a copper-decorated metal–organic framework by non-thermal plasma

• Published in: Cell reports physical science 2021-02, Vol.2 (2), p.100349, Article 100349
• Main Authors: Xu, Shaojun, Han, Xue, Ma, Yujie, Duong, Thien D., Lin, Longfei, Gibson, Emma K., Sheveleva, Alena, Chansai, Sarayute, Walton, Alex, Ngo, Duc-The, Frogley, Mark D., Tang, Chiu C., Tuna, Floriana, McInnes, Eric J.L., Catlow, C. Richard A., Hardacre, Christopher, Yang, Sihai, Schröder, Martin
• Format: Article
• Language: English
• Subjects: catalysis; copper; DRIFTs; EPR; low-temperature NOx reduction; metal-organic framework; MFM-300(Al); NO2; non-thermal plasma; XAFS
• ISSN: 2666-3864; 2666-3864
• DOI: 10.1016/j.xcrp.2021.100349

Efficient catalytic conversion of NO2 to non-harmful species remains an important target for research. State-of-the-art deNOx processes are based upon ammonia (NH3)-assisted selective catalytic reduction (NH3-SCR) over Cu-exchanged zeolites at elevated temperatures. Here, we describe a highly efficient non-thermal plasma (NTP) deNOx process catalyzed by a Cu-embedded metal-organic framework, Cu/MFM-300(Al), at room temperature. Under NTP activation at 25°C, Cu/MFM-300(Al) enables direct decomposition of NO2 into N2, NO, N2O, and O2 without the use of NH3 or other reducing agents. NO2 conversion of 96% with a N2 selectivity of 82% at a turnover frequency of 2.9 h−1 is achieved, comparable to leading NH3-SCR catalysts that use NH3 operating at 250°C–550°C. The mechanism for the rate-determining step (NO→N2) is elucidated by in operando diffuse reflectance infrared Fourier transform spectroscopy, and electron paramagnetic resonance spectroscopy confirms the formation of Cu2+⋯NO nitrosylic adducts on Cu/MFM-300(Al), which facilitates NO dissociation and results in the notable N2 selectivity. [Display omitted] MOF-based catalyst with plasma-activation to directly convert NO2Cu/MFM-300(Al) shows a high NO2 conversion, N2 selectivity, and long-term stabilityCu2+⋯NO nitrosylic adducts formed facilitate NO dissociation and N2 selectivity Nitrogen oxide causes significant effects on the environment and human health. Xu et al. report, to the best of their knowledge, the first example of nonthermal plasma-activated direct decomposition of NO2 over stable and efficient metal-organic framework-based catalysts at room temperature and without the use of NH3 or other reducing agents.