Ag Active Sites, Surface Intermediates and Hydrogen Function at Decane-SCR-NOx over Ag/Alumina

The state of silver and surface intermediates were simultaneously analyzed at real decane-SCR-NOx reaction conditions as well as at the individual reaction steps and those reactions under addition of hydrogen or H 2 O 2 with an attempt to elucidate the active Ag site and hydrogen function. The enhanced activity by the addition of hydrogen to the NOx SCR mix cannot be attributed exclusively to the formation of Ag clusters. The active sites are suggested to be Ag + ions and hydrogen itself takes part in the SCR-NOxreaction. It dissociates, forms Ag-hydride, and radical-type reactions are supposed to enhance SCR-NOx.