Field‐Emission Study of the Adsorption and Decomposition of Ammonia on Tungsten

摘要: The catalytic decomposition of ammonia on tungsten has been investigated by field electron‐emission microscopy. Physisorbed causes a large lowering work function (∼ − 2.8 eV). Ammonia chemisorbs at low temperatures the formation coordinate bond and heat adsorption activation energy for appear to be highest planes clean function. Decomposition nitrogen hydrogen occurs in interval 200°–400°K. Interaction with surface higher successive appearance three species, presently interpreted as N, NNH2, NNH3+. interaction adatoms produce additional species will proceed lower therefore requires little energy. rate‐limiting step is NNH2. proposed scheme satisfies existing kinetic data tungsten. implicati...