Experimental Study on Low Temperature Denitration Performance of Fe-Doped MnO/AC Catalyst

Traditional NH3-SCR requires high operation temperature (300 to 400 ºC), which limits the catalysts specific operation temperature. Low temperature denitration catalysts have relatively high denitration activity between 50 to 240 ºC, which could broaden their application. A series of bimetallic catalysts (Fe:Mn) were impregnated on coconut shell activated carbon (AC) as support, and low temperature denitration experiments were carried out in a fixed bed reactor with simulated flue gas. The catalysts were characterized by XRD, BET, SEM, and H2-TPR tests. The effects of Mn loading, Fe:Mn molar ratio, and temperature on denitration efficiency were evaluated. The results indicated that the elevated temperature (50 to 240 ºC) resulted in a higher denitration efficiency for Mn/AC with the maximum lower than 75%. Fe doping on Mn/AC promoted the dispersion of Mn as active component, thereby increasing the denitration activity. 6Fe10Mn/AC exhibited the best reactivity, and the denitration efficiency was over 90% between 160 to 240 ºC. However, the overloading of Fe covered part of the active sites of MnO, causing reactivity deterioration. A 20 h continuous operation indicated that the activated carbon AC exhibited excellent reactivity stability, showing good application prospects.