还原剂对Ag/Al2O3催化剂上NO还原的影响

在富氧条件下,研究了CH4、C3H8、C 3H6、C8H18、CH 3OH、C2H5OH,以及C3H6与CH3OH、C3H6与C2H5OH组合作还原剂时,在Ag/Al2O3催化剂上NO的还原活性.结果表明,不同碳氢化合物还原NO的活性温度存在较大的差异.SO2的存在会导致CH3OH还原NO的活性提高,而其他碳氢化合物还原NO的活性降低.随着还原剂浓度提高,NOx转化率增大,不过,过高的还原剂浓度对NO还原不利.组合使用CH3OH与C3H6或C2H5OH与C3H6作为还原剂,能显著拓宽活性温度范围.

Effects of reducing agents on NO reduction over Ag/Al2O3 catalyst

Selective catalytic reduction activity for NO conversion over Ag/Al 2O 3 has been investigated with CH 4, C 3H 8, C 3H 6, C 8H 18 , CH 3OH and C 2H 5OH, combinations of C 3H 6 and CH 3OH, or C 3H 6 and C 2H 5OH as reductants in the presence of excess oxygen. These reductants showed different active temperatures for NO reduction. The presence of SO 2 resulted in a significant increase of the activity for NO reduction by methanol and a decrease of the activity for NO reduction by the other reductants. NO reduction can be suppressed by too high HC concentration though it was improved with increasing reductant concentration under relatively low HC concentration. When combinations of propene and ethanol or methanol are used as reducing agents, NO reduction takes place over a wider temperature range, compared with a single hydrocarbon as reducing agent.