Publications

Metal nitride materials for solar-thermal ammonia production [Slides]

Ambrosini, Andrea A.; Bush, Hagan E.; Gao, Xiang G.; Berquist, Zachary B.; Anbar, Nathaniel A.; Stechel, Ellen B.; Miller, James A.

Solar Thermal Ammonia Production has the potential to synthesize ammonia in a green, renewable process that can greatly reduce the carbon footprint left by the conventional Haber-Bosch reaction. Co₃Mo₃N has been identified as a potential candidate for ammonia production. It is synthesized via oxide precursor synthesis followed by nitridation under 10% H₂/N₂. The synthesis method can be extended to other candidate nitrides. The Co₃Mo₃N → Co₆Mo₆N reduction is demonstrated on TGA with rapid kinetics. The formation of NH₃ is qualitatively observed, but not quantitatively determined. The material retains crystal structure, but no secondary phases are observed in XRD. Partial re-nitridation back to CMN331 of ~35% of max nitridation is observed. Reaction parameters in TGA differ from experimental conditions in the literature. Experiments at Georgia Tech better mimic re-nitridation conditions with more sensitive, quantitative analytical techniques (GC-MS). The ASU NH₃ synthesis/re-nitridation reactor is under development and will permit experiments (reduction/re-nitridation) under precisely controlled T, pH₂.