A series of Cu-ZSM-5 catalysts with different Cu loadings were prepared by an incipient wetness impregnation method. These catalysts were used for studies of selective catalytic reduction (SCR) of NO by NH3. The results showed that Cu-ZSM-5 with 5% Cu loading showed the best catalytic activity, the conversion of NO was more than 80% over the temperature range 198-470 ℃, and the highest NO conversion was 96.5%. The SCR activity was only influenced slightly by the addition of H2O or SO2. Visible diffraction of the CuO phase was observed when the Cu content was above 5%. The results of steady-state kinetics studies indicated that the SCR reaction over Cu-ZSM-5 with 5% Cu loading was zero-order with respect to NH3, first-order with respect to NO, and nearly half-order with respect to O2. The apparent activation energy for the reaction was found to be 47.7 kJ-mol"1.%采用浸渍法制备了一系列不同Cu载量的Cu-ZSM-5整体式催化剂.考察了该系列催化剂的NH3选择性催化还原(SCR) NO的反应特性.结果表明,当Cu质量分数为5％时,Cu-ZSM-5催化剂的SCR活性最高,此时催化剂上NO最高转化率高达96.5％,并且催化剂的活性窗口较宽,催化剂在198-470℃之间NO转化率大于80％.H2O和SO2的添加仅轻微影响Cu-ZSM-5催化剂的SCR活性.当Cu载量大于5％时,Cu-ZSM-5催化剂中出现明显的CuO物相.稳态动力学结果表明,在5％ Cu载量的Cu-ZSM-5上的SCR反应中,NO的反应级数接近一级,NH3的反应级数接近零级,O2的反应级数接近1/2级.该反应的表观活化能为47.7 kJ· mol-1
展开▼
