V2O5/AC催化剂吸附NH3及其选择性还原脱硝活性

在不同活性焦(Activated Coke, AC)载体上以等体积浸渍法负载V2O5，制备出一系列V2O5/AC催化剂. 通过NH3暂态响应实验和NH3穿透时间实验考察了在200℃下V2O5/AC的表面积、灰分、表面官能团和V2O5对NH3的吸附量及NO的选择性催化还原活性的影响. 结果表明，对于载体未经硝酸处理的催化剂，NH3的吸附位主要是V2O5(参与脱硝反应的NH3的吸附量与催化剂上V2O5负载量的比值为1:5)，活性焦及其中的灰分对NH3的吸附量很小；硝酸处理在活性焦表面引入的含氧和含氮酸性官能团对参与脱硝反应的NH3的吸附量是V2O5上吸附量的1.3倍，这些官能团不影响V2O5对NH3的吸附；活性焦上吸附的NH3的脱硝活性很低，但可迁移至V2O5上参与脱硝.

Adsorption and Selective Catalytic Reduction Reactivity of NH3 to NOx over V2O5/AC Catalyst

A series of V2O5/AC catalysts were prepared by loading 2%(w) V2O5 on different activated cokes (AC) with pore volume impregnation method. NH3 response experiments and NH3 adsorption experiments were carried out to study the effects of surface texture, ash content, surface functional groups and V2O5 on NH3 adsorption and selective catalytic reduction (SCR) of NO at 200℃. The results show that NH3 adsorbed on V2O5 is very active for the SCR (the ratio of adsorbed NH3 to V2O5 loading is 1:5), the support AC and its ash component have low activities toward NH3 adsorption, the HNO3 treatment of AC results in the increase of oxygen and nitrogen contents in the AC and in NH3 adsorption on the AC (the amount of NH3 adsorbed in oxygen-containing and nitrogen-containing functional groups is 1.3 times of that adsorbed in V2O5), most of NH3 on the AC is not active for the SCR of NO, but part of it participates in the SCR reaction through migration to the V2O5 sites.