Methanol Assisted Lean NOx Reduction Over Ag–Al2O3—Influence of Hydrogen and Silver Loading

Abstract

The influence of hydrogen and silver loading on lean NOx reduction with methanol over Ag–Al2O3 are investigated by flow-reactor experiments, H2-TPR, TEM and XPS. Reduction of silver at low temperatures over Ag–Al2O3 with high silver loading, suggests involvement of silver species/particles that are large (which is supported by the TEM analysis) and/or loosely bound to the support. The silver species reduced by hydrogen cannot be directly associated with the activity for NOx reduction under methanol-SCR conditions. Furthermore, the activity for NOx reduction increases slightly at low temperatures when hydrogen is added to the feed. However, also without co-fed hydrogen, a high low-temperature activity is achieved for methanol assisted lean NOx reduction over Ag–Al2O3.