The influence of precursor source and thermal parameters upon the formation of beta-phase molybdenum nitride

Solar thermochemical production of ammonia from water, air and sunlight: Thermodynamic and economic analyses

“…On the other hand, reactants forming metal oxides which can be reduced with H 2 unfortunately tend to not fix 0.1 MPa N 2 in form of metal nitrides and show low NH 3 yields when reacting their nitrides with steam [21]. Molybdenum considered here represents a trade-off [21]: The oxide, MoO 2 , that is formed during nitride (Mo 2 N) hydrolysis at above 800 K can be reduced [27] and nitridated with moderate yields in H 2 /N 2 gas mixtures in the range of 800 to 1500 K [28,29]. Given the relative high ionicity of the nitride [30,31], significant quantities of NH 3 are liberated during the hydrolysis of Mo 2 N at atmospheric pressure.…”

“…The energy-intensive process [13], including natural gas/steam reforming for H 2 production (accounting for approximately 84% of the total energy required), consumes [28][29][30][31][32][33][34][35][36][37][38][39][40] GJ/t NH 3 in form of natural gas [12,14] (about 1-2% of the world's annual energy production [15]). Approximately 2.3 t of fossil-derived CO 2 are generated per t NH 3 synthesized [14].…”

Redox supercapacitor performance of nanocrystalline molybdenum nitrides obtained by ammonolysis of chloride- and amide-derived precursors

“…The α-phase is molybdenum metal with small amounts of dissolved nitrogen, whereas β-Mo 2 N is tetragonally distorted rocksalttype with ordered stacking faults, and requires careful control of conditions for its synthesis [4,5], and Mo 5 N 6 has been obtained by ammonolysis of molybdenum sulfide [6].…”

“…Later the same group used temperature programmed reduction of MoO 3 to produce 16 nm γ-MoN crystallites and found both a high specific capacitance (172 F g -1 ) and an increased potential window (1.1 V) [22]. Choi et al reacted MoCl 5 in chloroform with ammonia then heated the precipitate in ammonia to make γ-MoN with ~110 F g -1 capacity at 2 mV s -1 but poorer performance at faster rates and ~40% loss of capacity over 500 cycles [23]. Recently Lee et al used ammonolysis of single crystal MoO 3 nanowires to make mesoporous Mo 3 N 2 wires which exhibited higher capacities than the same material made from commercial MoO 3 and maintained a capacity over 200 F g -1 even at a charge/discharge rate of 200 mV s -1 [24].…”

“…Synthesis of molybdenum nitrides commonly involves heating a suitable precursor material in ammonia including the metal [25] and MoCl 5 [2,26,27], whereas carefully controlled ammonolysis of MoO 3 [5,28] and various other oxide-containing materials [29,30] have been used to obtain high surface area materials suitable for catalysis. Vapour phase deposition methods for films are also well developed [14,31], and high pressure has been used in a number of cases to obtain stoichiometry or more crystalline products [3,32].…”