Atomistic origin of mechanochemical NH3 synthesis on Fe catalysts

• DOI: 10.1016/j.ijhydene.2022.10.193
• Publication Date: 2022-11-17T06:55:48Z
• Authors: Hong Woo Lee; Ga-Un Jeong; Min-Cheol Kim; Donghun Kim; Sooyeon Kim; Sang Soo Han
• Keywords: ReaxFF; Force Field; Ammonia production

A tremendous amount of ammonia (NH3) has been produced by the Haber-Bosch method during last 100 years. However, it is imperative to develop a new alternative produce NH3 in more environmentally friendly way due high energy cost and large greenhouse gas emissions method. Although mechanochemical process regarded as an emerging technique, understanding at atomic level limited. Here, we computationally model ball-milling molecular dynamics simulations with reactive force field (ReaxFF) developed this work. We find that strain applied Fe surfaces significantly enhances N2 dissociation well NHx (x = 1–3) formation on Fe(110), whereas effect negligible Fe(111). From von Mises stress analyses, (mechanical) energies transfer catalysts N atoms adsorbed then activate formation. Moreover, mechanical boosts mechanism for NH formation, rate-determining step, via direct interaction between dissociated atom surface H2 molecule, which supported density functional theory calculations. This study shows readily operated promising synthesis.