Influence of gas hourly space velocity on the activity of monolithic catalysts for the simultaneous removal of soot and NOx

Cordierite-supported structured catalysts were prepared with several alumina-based suspensions containing K, Cs or Ba as alkali promoter, and Co, or Cu as active metals. The prepared catalysts were tested in a lab installation with a gas hourly space velocity (GHSV) from 1300 h−1 to the one representative of the exhaust gases of a diesel engine, i.e. GHSV = 36,690 h−1. Significant differences in the behavior of the catalysts are observed when increasing the GHSV, pointing to different predominant factors taking place in each case depending on the active metal and the alkali promoter used.