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

A Fourier transform infrared absorption spectroscopy (FTIR) study showed that NH(3) was formed by the successive reaction of hydrogen atoms with nitrogen atoms in an N(2) matrix at 10 K. Reactions appeared to proceed via the Langmuir-Hinshelwood mechanism because NH(3) formation was not observed at 20 K. At this temperature, H atoms did not adsorb significantly onto the N(2) matrix; i.e., the surface residence times were short. Furthermore, NH(3) yields via the successive hydrogenation of N atoms were significant, even after H atom deposition onto the N(2) matrix containing trapped N atoms onto which had been deposited a superficial pure solid N(2) adlayer. This result clearly indicates that H atoms diffuse in pure solid N(2) matrices at 10 K.