| 초록 |
Ag/Al2O3 shows very high catalytic performance on the H2-assisted selective catalytic reduction of NO by hydrocarbons (H2-HC-SCR), which is one of the promising technologies for removal of NO in diesel engine exhausts. A mechanistic study using in-situ UV-Vis, EXAFS, in-situ FT/IR, and DFT clarified that the higher rate of NO reduction by HC-SCR is accompanied by the formation of Ag cluster, which promotes (1) formation of Ag-hydride, (2) activation of O2 by Ag-hydride to form H2O2-like species, (3) hydrocarbon partial oxidation by the H2O2-like species to form oxygenated hydrocarbons, then (4) reduction of surface NOx (nitrates) species by oxygenated hydrocarbons. Knowing the essential role of Ag cluster on HC-SCR, it was found that Ag/Al2O3 can be applied to oxidant-free dehydrogenation of alcohols. We also developed other reactions using Ag cluster, i.e., direct C-C crosscoupling of alcohols, direct amide synthesis from alcohols and amines, N-benzylation of anilines with alcohols, and selective hydrogenation of nitroaromatics. |
