Nitride-Based Noble Metal-Free Catalysts for Ammonia Synthesis

Abstract

Nitride-based materials such as BaCeO_3-xN_yH_z and LaN enable the activation of N₂ at nitride-vacancy sites with the help of spill-over hydrogen from transition metal surface. Fe, Co, and Ni nanopartilces combined with these nitrides function as efficient catalysts for ammonia synthesis through the lattice anion vacancy-mediated Mars-van Krevelen mechanism, while ammonia synthesis occurs over conventional catalysts through a Langmuir-Hinshelwood mechanism. As a result, these nitride-based catalysts surpass the activity of conventional Ru-based catalysts.