Bridging the pressure and material gap in the catalytic ammonia oxidation : structural and catalytic properties of different platinum catalysts

To understand the "pressure and material gap" in the platinum-catalyzed ammonia oxidation over Pt, the reaction was studied over a wide range of pressures (10-3–105 Pa) and temperatures (293–1073 K) with different Pt catalysts: stepped Pt(533) single crystal, knitted Pt gauze, and Pt foil. Experiments were supplemented by theory applying DFT calculations. It was concluded that the primary reaction step of NH3 oxidation, stripping of hydrogen from the NH3 molecule, is favored by the presence of surface O and OH species. The latter species are more active for dehydrogenation of NH2 and NH fragments. NO and N2 are the only nitrogen-containing products detected under UHV conditions (p