Promotion effect of H2 on the low temperature activity of the selective reduction of NO by light hydrocarbons over Ag/Al2O3

The effect of H-2 on the selective reduction of NO by light hydrocarbons over Ag/Al2O3 catalyst under lean-exhaust conditions was investigated. The NO reduction activity at the low temperature region was markedly increased by adding H-2. The NO reduction activity at high GHSV condition and SO2 tolerance were also improved by adding H-2. Since the NO was reduced little by H-2 in the absence Of C-3 H-8, H-2 should act as a promoter of NO reduction by hydrocarbons over Ag/Al2O3 The results of reaction studies and in situ IR experiments showed that the possible reasons for promoting the effect by H-2 on the HC-SCR were mainly caused by the activation of hydrocarbons. (C) 2002 Elsevier Science B.V. All rights reserved.