Interaction of hydrazine and ammonia with TiO2

Abstract

Adsorption and reaction of N2H4 and NH3 on powdered TiO2 have been studied by Fourier-transformed infrared spectroscopy. N2H4 decomposes on the surface to form NH3 and surface hydroxy groups at temperatures higher than ∽150°C. Based on these findings, a N2H4 reaction pathway on TiO2 is established to be N2H4→2NH2→NH+NH3 and NH+O(l)→N+OH(ads). NH3 decomposes on the surface and forms adsorbed azide N3(ads) species at temperatures higher than ∽350°C. Photooxidation of NH3 and ND3 is investigated as well and the mechanism is discussed in terms of the NH2 reaction pathway and recent reports for the reactions between NHx and NOx (x=1–2) in the gas phase.