Novel Enolic Surface Species Formed during Partial Oxidation of CH₃CHO, C₂H₅OH, and C₃H₆ on Ag/Al₂O₃:  An in Situ DRIFTS Study

In situ DRIFTS was used to investigate the formation and reactivity of surface species on Ag/Al 2 O 3 during partial oxidation of CH 3 CHO, C 2 H 5 OH, and C 3 H 6 . The exposure of Ag/Al 2 O 3 to CH 3 CHO/C 2 H 5 OH/C 3 H 6 + O 2 in a steady state leads to the formation of two kinds of partial oxidation products: acetate and a novel enolic surface species. Peaks at 1633, 1416, and 1336 cm -1 are assigned to an adsorbed enolic species. The adsorbed enolic species is more prone to react with NO + O 2 on Ag/Al 2 O 3 than acetate is, and plays a crucial role in the formation of NCO, which is a key intermediate during selective catalytic reduction of NO.