Ag/Al2O3催化剂用于碳氢化合物选择性还原NO

比较了富氧条件下CH4、C3H8、C3H6和C2H5OH分别用作还原剂时,NO在Ag/Al2O3催化剂上的还原活性.结果表明, CH4和C3H8还原NO的活性很低,而C3H6和C2H5OH能有效地还原NO.在此基础上,研究了H2O和SO2对C3H6和C2H5OH在Ag/Al2O3催化剂上还原NO活性的影响.结果表明,H2O的存在会降低低温区的NO还原活性,而且这种影响是可逆的.将H2O 和SO2同时加入反应混合气,引起NO还原活性较大幅度降低,结合程序升温脱附实验结果,认为可能是由于存在SO2时,Ag/Al2O3催化剂吸附NO的能力降低.

Application of the Ag/Al2O3 catalyst in the selectively catalytic reduction of NO by hydrocarbons

Selectively catalytic reduction activities of NO over Ag/Al2O3 catalyst were compared under the condition of rich oxygen when, methane, propane, propene and ethanol were used as the reducing agents, respectively. The results showed that the former two hydrocarbons had relatively low NO reduction activities while propene and ethanol could effectively reduce NO. On this basis, the effect of H2O and SO2 on the NO reduction by propene and ethanol over the catalyst was investigated. The results showed that the NO reduction activity decreased below the peak temperature in the presence of H2O and the inhibition effect was reversible. The simultaneous addition of H2O and SO2 to the mixed reaction gas caused a significant decrease of activity, which was attributed to the decrease in the chemisorption of NO on the catalyst in the presence of SO2 according to temperature-programmed desorption (TPD) result.