Co-blending modification of activated coke using pyrolusite and titanium ore for low-temperature NOx removal

Activated coke (AC) has great potential in the field of low-temperature NO removal (DeNO_x), especially the branch prepared by blending modification. In this study, the AC-based pyrolusite and/or titanium ore blended catalysts were prepared and applied for DeNO_x. The results show blending pyrolusite and titanium ore promoted the catalytic performance of AC (Px@AC, Tix@AC) clearly, and the co-blending of two of them showed a synergistic effect. The (P/Ti-1/2)15@AC performed the highest NO conversion of 66.4%, improved 16.9% and 16.0% respectively compared with P15@AC and Ti15@AC. For the (P/Ti-1/2)15@AC DeNO_x, its relative better porous structure (S_BET = 364 m²/g, V_mic = 0.156 cm³/g) makes better mass transfer and more active sites exposure, stronger surface acidity (C-O, 19.43%; C=O, 4.16%) is more favorable to the NH₃ adsorption, and Ti, Mn and Fe formed bridge structure fasted the lactic oxygen recovery and electron transfer. The DeNO_x of (P/Ti-1/2)15@AC followed both the E-R and L-H mechanism, both the gaseous and adsorbed NO reacted with the activated NH₃ due to the active sites provided by both the carbon and titanium.