Kinetic evidence: the rate-determining step for ammonia synthesis over electride-supported Ru catalysts is no longer the nitrogen dissociation step

Abstract

Using kinetic analysis, we demonstrate that the rate-determining step for ammonia synthesis over Ru catalysts supported by electrides, such as [Ca₂₄Al₂₈O₆₄]⁴⁺(e⁻)₄ and Ca₂N:e⁻, is not the N₂ dissociation step but the subsequent surface reactions of N and H adatoms, in which case the Langmuir–Hinshelwood model should be used to describe the kinetics.