Fe-MnO_x-CeO_2/ZrO_2低温催化还原NO性能研究

Low-Temperature Catalytic Reduction of NO over Fe-MnO_x-CeO_2/ZrO_2 Catalyst

以纳米ZrO2为载体,用浸渍法制备出Fe-MnOx-CeO2/ZrO2催化剂,考察了活性组分配比和助剂负载量对催化剂低温NH3选择性催化还原NO活性的影响,并对催化剂进行了XRD、SEM、EDS和BET表征;探讨了温度、H2O和SO2对Fe-MnOx-CeO2/ZrO2催化剂低温下NH3选择性催化还原NO的影响,结果表明,无SO2和H2O条件下,8%Fe-10%MnOx-CeO2/ZrO2催化剂具有良好的催化活性和稳定性.120℃时,催化剂的脱硝效率为85.23%,当温度升至180℃时,脱硝效率可达到92.0%.SO2和H2O共存条件下,催化剂易失活,采用傅立叶变换红外光谱对各反应阶段的催化剂进行了表征,对其失活机制进行深入研究,结果表明,催化剂失活的主要原因是催化剂表面硫酸铵盐的沉积和催化剂本身活性成分的硫酸盐化.

Fe-MnOx-CeO2/ZrO2 catalysts were prepared through impregnation method with nanometer ZrO2 as a carrier and used in selective catalytic reduction of NO with NH3 at low temperature.Effects of active component ratio and loading of promoter on the catalyst activity were investigated.The catalysts were characterized by means of XRD,SEM,EDS and BET.The effects of temperature,SO2 and H2O on NO conversion were studied and the results showed that in the absence of SO2 and H2O,the catalyst of 8%Fe-10%MnOx-CeO2/ZrO2 had good activity and stability as well as the NOx removal efficiency reached 85.23% at 120℃ and 92.0% at 180℃.The presence of SO2 and H2O results in the catalyst deactivated.Properties of the catalyst on different reaction stages were characterized by FT-IR to study the inactivation mechanism of the catalyst.The results showed that the catalyst deactivation was due to the deposition of ammonium sulfate on the catalyst and the sulphation of the catalyst.