The interactions of Li3FeN2 with H2 and NH3

Li3FeN2 was synthesized by calcinating equivalent Li3N and Fe under N2 atmosphere and 700 °C. The interactions of Li3FeN2 with H2 and NH3 were studied by using XRD, Mössbauer spectroscopy, temperature-programmed reaction and isothermal (de)hydrogenation. Our results show that the hydrogenation of Li3FeN2 gives rise to Fe metal rather than FeN following the reaction of Li3FeN2 + 2.5H2 = 2LiNH2 + LiH + Fe. Whereas heating the mixture of 2LiNH2/LiH/Fe results in a two-step dehydrogenation that partially regenerates Li3FeN2. Furthermore, Li3FeN2 can react easily with ammonia at room temperature, forming LiNH2 and an amorphous FeN-containing compound. At higher temperatures Li3FeN2 outperforms Fe2N in catalyzing ammonia decomposition.