In situ DRIFTS studies on MnOx nanowires supported by activated semi-coke for low temperature selective catalytic reduction of NOx with NH3

摘要

To mitigate the threat of NO, on the environment, MnO, nanowires were fabricated on activated semi coke (MnO, NW/ASC) for the first time. The prepared MnO, NW/ASC was used for the low temperature selective catalytic reduction (SCR) of NO, with NH3, which achieved an efficiency of over 90% with a low loading content of 1.64 wt% at 150-210 degrees C. This high performance could be ascribed to synergistic effect between MnO, and ASC. Specifically, the large specific surface area and reducible property of ASC facilitated the dispersion of MnO, and the formation of Mn3+, respectively. Meanwhile, MnO, nanowires provided more redox sites and lattice oxygen species due to the coexistence of Mn3+ and Mn4+, which accelerated the catalytic cycle. The in situ DRIFTS studies revealed that ASC was conducive to the adsorption of NO and NH3. Most importantly, the existence of Mn3+ favored the formation of amide species and the subsequent reduction reaction. Furthermore, the Langmuir-Hinshelwood (L-H) route between coordinated NH3 and bidentate nitrate was predominating in the SCR process and responsible for the high catalytic activity at low temperature. (C) 2016 Published by Elsevier B.V.