Metal organic framework-derived manganese-cobalt oxide with high SO2 resistance for low-temperature NH3-SCR
摘要
Manganese-cobalt oxide catalyst (MnxCo3-xO4-H) with honeycomb structure was prepared from MnCo-BTC (BTC = 1,3,5-benzenetricarboxylic acid). Its honeycomb structure was inherited from MnCo-BTC with nanoneedle structure and MnxCo3-xO4-H had a bigger surface area (57.63 m2/g) than that (10.06 m2/g) of MnxCo3-xO4-C prepared by coprecipitation. The MnxCo3-xO4-H and MnxCo3-xO4–C catalysts were tested for low-temperature selective catalytic reduction of NOx with NH3 (NH3-SCR) and compared with MnxCo3-xO4–C catalyst. As a result, MnxCo3-xO4–H derived from MnCo-BTC exhibited the superior deNOx activity, which showed 99% NOx conversion at the existence of 100 ppm SO2 and 200 °C. To characterize the MnxCo3-xO4–H and MnxCo3-xO4–C catalysts, X-ray diffraction (XRD), scanning electron microscopy (SEM) and temperature-programmed desorption experiments of SO2 (SO2-TPD) were employed. The SO2-TPD results showed that MnxCo3-xO4–H had the weaker SO2 adsorption than MnxCo3-xO4–C catalyst, resulting in high SO2 resistance. Finally, based on the in situ DRIFT experiments, it was demonstrated that SO2 adsorption on MnxCo3-xO4–H catalyst was suppressed and the effect of SO2 on the adsorption of the reactant gases was lower than MnxCo3-xO4–C catalyst, thus resulting good SO2 resistance. This work expanded the possible applications of metal organic framework i– the SCR field.
Graphical abstractIt was demonstrated that SO2 adsorption on MnxCo3-xO4–H catalyst (a) was suppressed and the effect of SO2 on the adsorption of the reactant gases was lower than MnxCo3-xO4–C catalyst, thus resulting good SO2 resistance.