Influence of phase changes, nucleation and particle growth on the activity of tungsten as a catalyst for the ammonia-decomposition reaction

The activity of tungsten as a catalyst for the NH3 decomposition reaction has been investigated using an initial NH3 pressure of 300 Torr and a catalyst temperature of 1250 K. The nitriding of the tungsten was followed by thermal desorption of the nitrogen taken up by the catalyst. In experiments where the nitride was decomposed in this manner the activity for NH3 decomposition was found to increase by a factor of two in an autoaccelerating …