FTIR study of ammonia formation via the successive hydrogenation of N atoms trapped in a solid N2 matrix at low temperatures

Abstract

A Fourier transform infrared absorption spectroscopy (FTIR) study showed that NH₃ was formed by the successive reaction of hydrogen atoms with nitrogen atoms in an N₂ matrix at 10 K. Reactions appeared to proceed via the Langmuir–Hinshelwood mechanism because NH₃ formation was not observed at 20 K. At this temperature, H atoms did not adsorb significantly onto the N₂ matrix; i.e., the surface residence times were short. Furthermore, NH₃ yields via the successive hydrogenation of N atoms were significant, even after H atom deposition onto the N₂ matrix containing trapped N atoms onto which had been deposited a superficial pure solid N₂ adlayer. This result clearly indicates that H atoms diffuse in pure solid N₂ matrices at 10 K.