The Research Of Ammonia Decomposition Via Plasma-catalysis

Ammonia is an attractive non-carbonaceous hydrogen resource for fuel cell car, noble metal Ru supported catalyst has proved to be effective in catalyzing the decomposition of ammonia for hydrogen generation so far, however they are too expensive to be used commercially. It is feasible for ammonia decomposition over non-noble metal catalyst ,but require high temperature more than 600°C, which is adverse for application. So it is attractive to effectively decompose ammonia over non-noble metal catalyst at lower temperature .It is generally accepted that, under the action of dielectric barrier discharge, gas molecules are partially ionized. Electrons thus generated soon get power from the HV electric field and become energetic electrons (temperature: 1-10 e V ). The partially ionized gas that contains energetic electrons is called non-equilibrium plasma (NEP). By means of inelastic collision, the energy of the energetic electrons is transferred to heavy particles (including molecule, atom and ions). As a result, the heavy particles are converted into chemically active species via excitation, fragmentation and ionization process. Such active species are so active that they can result in chemical reaction at room temperature.In this paper, the research of H₂ produced from ammonia via plasma-catalysis is studied. The preparation of Ni, Fe, Cu catalyst and the effect of plasma-catalysis are reported. The purpose is to find an effective non-noble metal catalyst for ammonia decomposition via plasma-catalysis.Results show that:(1) The catalytic performance of the combined method of the dielectric barrier discharge (DBD) non-equilibrium plasma and the non-noble metal supported catalyst for the decomposition of ammonia is reported for the first time. Results show that, the novel plasma-catalysis method can significantly enhance the catalytic activity of non-noble metal supported catalyst and the energy efficiency of discharge triggered reactions. Under the conditions of 1 atm, 450 °C and ammonia feeding velocity 850 h^-11 (volume), a >99% ammonia conversion and a 664 L (STD) / kw. h energy efficiency have been achieved by the combined actions of a NiO/Al₂O₃ catalyst and the DBD non-equilibrium plasma.(2) Under the same conditions the ammonia conversion is only 5.9% for NiO/Al₂O₃ catalyst, and 17.8% for the DBD non-equilibrium plasma., but the conversion of ammonia is beyond 99% via plasma-catalysis. The strong synergetic effect of the non-equilibrium plasma and the non-noble metal supported catalyst in the decomposition of ammonia is attributed to...