Effect of Ag–Co interactions in the mordenite on the NOx SCR with butane and toluene

A study of the lean NOx reduction activity with butane and toluene in the presence of water over bimetallic and monometallic Ag, Co exchanged on Na-mordenite catalysts was performed. The Ag–Co interactions were analyzed through X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) techniques. It is shown that the metal silver particles formed at low temperature during the TPR experiment improve the dissociation of hydrogen thus facilitating the reduction of Co2 + species. The incorporation of 3.2 wt.% of silver to CoM catalyst, significantly improved the NOx to N2 conversion with butane, which reached 95% under wet conditions (2% H2O). However, this effect was not observed when toluene was the reducing agent.

Figure optionsDownload as PowerPoint slideHighlights
► The addition of Ag promotes NOx reduction when butane is the reductant.
► The reduction of Co species is promoted by the Ag+ ions.
► The Co2 + ions are more reactive than the Ag+ species in the SCR-NOx reaction.
► On bimetallic AgCoM with C4H10 and 2% of H2O, NOx conversion reaches 95%.
► There is a poisoning effect of coking at low temperature with C7H8.