Detection of key transient Cu intermediates in SSZ-13 during NH3-SCR deNOx by modulation excitation IR spectroscopy
Open Access
- 18 November 2019
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Chemical Science
- Vol. 11 (2) , 447-455
Abstract
The small pore zeolite Cu-SSZ-13 is an efficient material for the standard selective catalytic reduction of nitrogen oxides (NOx) by ammonia (NH3). In this work, Cu-SSZ-13 has been studied at 250 °C under high conversion using a modulation excitation approach and analysed with phase sensitive detection (PSD). While the complementary X-ray absorption near edge structure (XANES) spectroscopy measurements showed that the experiments were performed under cyclic Cu+/Cu2+ redox, Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) experiments provide spectroscopic evidence for previously postulated intermediates Cu–N(O)–NH2 and Cu–NO3 in the NH3-SCR deNOx mechanism and for the role of [Cu2+(OH−)]+. These results therefore help in building towards a more comprehensive understanding of the reaction mechanism which to date has only been postulated in silico.Keywords
Funding Information
- Engineering and Physical Sciences Research Council (EP/K014706/1, EP/K014668/1, EP/K014854/1, EP/K014714/1, EP/I019693/1)
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