烟气中Fe_(2)O_(3)对商用V-Mo/Ti脱硝催化剂的性能影响研究

Investigation of Fe_(2)O_(3) on the Catalytic Performance of Commercial V-Mo/Ti De-NO_(x) Catalyst in Flue Gas

为明确燃煤烟气飞灰中Fe_(2)O_(3)对商用脱硝催化剂的影响,采用浸渍法制备了不同Fe_(2)O_(3)负载量的V-Mo-Fe/Ti脱硝催化剂。通过XRF、XRD、N_(2)-吸附脱附、NH 3-TPD、H_(2)-TPR、XPS等表征手段对催化剂的物理化学性能进行分析。随后,使用固定床微型反应评价装置对催化剂进行了脱硝性能检测。结果表明,Fe_(2)O_(3)的负载对催化剂的晶型和孔结构影响不大,却能提升催化剂的酸性和还原性能。然而,Fe_(2)O_(3)同时会对催化剂活性位产生覆盖作用,导致催化剂化学吸附氧含量以及脱硝活性的降低。此外,Fe_(2)O_(3)会增加硫酸氢铵在催化剂上的沉积,影响催化剂的运行稳定性。

V-Mo-Fe/Ti de-NO_(x)catalysts with different amounts of Fe_(2)O_(3)were prepared by impregnation method to investigate the influence of Fe_(2)O_(3)in fly ashes from coal-fired power stations on the catalytic performance of commercial de-NO_(x)catalyst.The catalysts were characterized by XRF,XRD,N_(2)adsorption-desorption,NH 3-TPD,H_(2)-TPR,XPS,etc.Furthermore,the denitrification performances of the different catalysts were compared through a fixed-bed micro-reactor.It was found that the doping of Fe_(2)O_(3)had little impact on the structure and pore property of V-Mo/Ti catalyst but increased its acidity and reducibility.However,Fe_(2)O_(3)covered the active sites of the catalyst,which led to the decrease of the amount of chemisorbed oxygen and de-NO_(x)activity of the catalyst.Besides,Fe_(2)O_(3)facilitated the deposition of ammonium bisulfate on the catalyst during the SCR reaction.As a result,the stability of the catalyst declined.