Facile synthesis of flake‐like MnO 2 /CNFs catalysts and their activity in low‐temperature NO reduction with NH 3

Abstract

A series of MnO2/carbon nanofibres (CNFs) catalysts were prepared by a facile co-precipitation method for low-temperature selective catalytic reduction (SCR) of NO with NH3. These catalysts were characterised by the techniques of specific surface area measurements (BET), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and H2 temperature-programmed reduction (H2-TPR). The XRD, FESEM and TEM results showed that the CNFs were surrounded by MnO2 nanoflakes. Compared with the MnO x /CNFs catalyst prepared by the wet impregnation method, the MnO2/CNFs catalysts exhibited better low-temperature SCR activity at low temperature. The XPS results indicated that a higher concentration of Mn4+ and more surface oxygen species exited on the surface for 8% MnO2/CNFs catalyst. The H2-TPR profiles displayed that the 8% MnO2/CNFs catalyst presented stronger low-temperature reducibility than the MnO x /CNFs catalyst. Based on the abovementioned favourable properties, the 8% MnO2/CNFs catalyst has an excellent performance in the low-temperature SCR of NO with NH3.