氨合成铁催化剂上氮吸附态的研究——Ⅰ.氨合成铁催化剂表面上吸附氮的激光Raman光谱和红外光谱

Abstract

[英文摘要]Chemisorption of N2 in the presence of H2 at 400℃ on (a) doubly-promoted commercial iron catalyst A110-3 and (b) Fe-Al (Raney iron), as well as on (c) Fe/MgO, has been investigated with a combination of laser Raman (Spex RamaIog-6) and IR (Hilger H887, and Pcrkin-Elmer 577) spectroscopy for the first time. The Raman bands observed at (a) 1936 cm-1, (b) 1930 cm-1, and (c) 1994 cm-1, respectively, may be assigned to N≡N stretching of chemisorbed N2, corresponding Raman bards not being observed with pure H2 on the above three catalysts.A μ7(η2,ω2,ω')"flatlying mode"of N2 coordination previously proposed by us on 7-Fe cluster of α-Fe(111)surface has been discussed together with other modes of N2 coordination.