Catalytic decomposition of NO2 over a copper-decorated metal–organic framework by non-thermal plasma
Shaojun Xu, Xue Han, Yujie Ma, Thien D. Duong, Longfei Lin, Emma K. Gibson, Alena M. Sheveleva, Sarayute Chansai, Alex S. Walton, Duc-The Ngo, Mark D. Frogley, Chiu C. Tang, Floriana Tuna, Eric J. L. McInnes, C. Richard A. Catlow, Christopher Hardacre, Sihai Yang⧫, Martin Schröder
Abstract
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.