The Decomposition of Ammonia on Tungsten Surfaces

Abstract

<p>This thesis presents an experimental study of the decomposition of ammonia on tungsten surfaces. The investigations were made at ammonia pressures between 10⁻⁷ and 10⁻² torr, and at temperatures between 200 and 800ºK by employing thermal desorption mass spectrometry and field emission microscopy. The surface species formed during the interaction were first isolated and the rate parameters for the formation and desorption of these species were determined. The properties of the adlayer of these species were also studied. Based on the rate parameters for the formation and desorption of these species a satisfactory mechanism for the decomposition of ammonia on tungsten surfaces has been deduced.</p>