ZrN6‐Doped Graphene for Ammonia Synthesis: A Density Functional Theory Study. Issue 8 (16th January 2023)

• Record Type: Journal Article
• Authors: Wu, Jing; Yang, Lei; Liu, Xin; Zhang, Ze; Liu, Shanping; Xiao, Beibei
• Is Part Of: Chemphyschem. Volume 24:Issue 8(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-16
• Subjects: nitrogen reduction reaction -- density functional theory -- graphene -- thermodynamics -- electrocatalysts; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.202200864
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Considering the pivotal role of ammonia in the modern chemical industry, designing effective catalysts for the N2 ‐to‐NH3 conversion stimulates great research enthusiasms. In this work, by means of density functional theory calculations, we systematically investigated the electrocatalysis of six‐coordinated transition metal atom anchored graphene for nitrogen fixation. The free energy analysis shows that the ZrN6 configuration has a good activity toward ammonia synthesis under overpotential of 0.51 V. According to the electron transfer analysis, ZrN6 site plays a bridging role in charge transfer between the functional graphene and the reactant. Furthermore, the presence of N6 coordination increases the electron accumulation on the NNHx intermediates, which weakens the intermolecular N−N bond, reducing the thermodynamic barrier of protonation process. This work provides a basic understanding of the interaction between transition metal and the adjacent coordination in tuning the reactivity. Abstract : Ammonia synthesis : ZrN6 or MoN3 C3 doped graphene effectively catalyzes ammonia synthesis under 0.51 V overpotential. However, the VN6 and NbN6 moieties suffer from the competitive hydrogen evolution reaction, despite the low overpotentials, while the ScN3 C3 site is limited by the high overpotential toward nitrogen reduction.