High Throughput Screening of Transition Metal Binuclear Site for N2 Fixation

TL;DR

This study uses high throughput screening to identify a Fe-Fe dual atom catalyst on graphite carbon nitride with exceptional N2 reduction performance, achieving near-perfect efficiency and the lowest limiting potential reported.

Contribution

It introduces a novel Fe-Fe dual atom site catalyst design for NRR with superior activity and selectivity, supported by first-principles screening and detailed electronic structure analysis.

Findings

Fe2/gCN achieves 100% Faradic efficiency for NH3.

Limiting potential as low as -0.13 V, lowest among theoretical results.

Identifies electronic descriptors correlating structure with activity.

Abstract

Great enthusiasm in single atom catalysts (SACs) for the N2 reduction reaction (NRR) has been aroused by the discovery of Metal (M)-Nx as a promising catalytic center. However,the performance of available SACs,including poor activity and selectivity,is far away from the industrial requirement because of the inappropriate adsorption behaviors of the catalytic centers. Through the first principles high throughput screening, we find that the rational construction of Fe-Fe dual atom centered site distributed on graphite carbon nitride (Fe2/gCN) compromises the ability to adsorb N2H and NH2, achieving the best NRR performance among 23 different transition metal (TM) centers. Our results show that Fe2/gCN can achieve a Faradic efficiency of 100% for NH3 production. Impressively, the limiting potential of Fe2/gCN is estimated as low as -0.13 V, which is hitherto the lowest value among the reported theoretical results. Multiple level descriptors (excess electrons on the adsorbed N2 and integrated crystal orbital Hamilton population) shed light on the origin of NRR activity from the view of energy, electronic structure, and basic characteristics. As a ubiquitous issue during electrocatalytic NRR, ammonia contamination originating from the substrate decomposition can be surmounted. Our predictions offer a new platform for electrocatalytic synthesis of NH3, contributing to further elucidate the structure-performance correlations.