▎ 摘　　要

Graphene oxide (GO) was synthesized using an improved Hummers method. Subsequently, catalysts of manganese oxides (at varying loadings) supported on graphene (MnOx/GR) were prepared by hydrothermal reaction for application in the selective catalytic reduction (SCR) of NOx with NH3 at low temperatures. The structural properties and catalytic performance were evaluated by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), N-2 adsorption-desorption, X-ray photoelectron spectroscopy (XPS), and H-2 temperature-programmed reduction (H-2-TPR). The characterization results indicated that abundant functional groups existed on the surface of the prepared GO that could combine with manganese during preparation of the catalysts. Manganese oxide entities, with different crystallinities (MnO, Mn3O4, or MnO2), were dispersed on the surface of graphene. The results of the catalytic studies showed that the MnO/GR catalysts prepared with different MnOx loadings all exhibited excellent low-temperature SCR activities. The catalyst with 20%(w) MnOx displayed the best activity, which was attributed to the high content of high-valent manganese and oxygen adsorbed onto the catalyst surface, as well as to the enhancement in redox abilities and the addition of active sites at low temperatures.