Synthesis of Complex Transition Metal Nitrides and their Ammonia Synthesis Activity

Abstract

n this study, some nanocrystalline quaternary interstitial nitrides adopting the filled beta-Mn and the η-6 carbide type structures have been synthesised using a modified Pechini method. This method, which involves dissolving metal salts with citric acid followed by the evaporation and ammonolysis of the resulting oxide precursors, has resulted in the nanoparticle materials. It has been shown to be a useful tool for producing homogeneous quaternary nitrides in a fast and simple way. The structural properties of the samples were examined by powder X-ray diffraction and the data was further analysed and quantitatively refined using Rietveld refinement methods. Other characterisation techniques such as SEM, TEM, TGA and elemental analysis of carbon, hydrogen and nitrogen content were also undertaken. The surface areas of the materials were measured by the Brunauer- Emmett- Teller (BET) method, using nitrogen adsorption isotherms