Theoretical Investigation of Single and Double Transition Metals Anchored on Graphyne Monolayer for Nitrogen Reduction Reaction

Abstract

In contrast to the energy-extensive Haber–Bosch process, green production of ammonia (NH3) at ambient conditions remains as one of the main goals of the 21st century. In this work, we systematically studied single and double transition metal atoms (Fe, Co, Mo, Ru) anchored on graphyne (GY) for nitrogen (N2) reduction by means of density functional theory (DFT). We demonstrated that Ru dimer anchored on two-dimensional (2D) GY exhibits superior catalytic activity for nitrogen reduction via an enzymatic pathway with the maximum free energy change (ΔG) of 0.43 eV. Our findings propose highly reactive catalytic materials for efficient N2 reduction while highlighting the importance of double-atom catalysts for nitrogen reduction reaction (NRR).

Molybdenum Atom-Mediated Salphen-Based Covalent Organic Framework as a Promising Electrocatalyst for the Nitrogen Reduction Reaction: A First-Principles Study

“…Therefore, we can say that due to the less energy input requirement via the distal pathway, NRR on Mo-salphenCOF preferably proceeds through the distal mechanism. The limiting potential found in the case of Mo-salphenCOF (−0.33 V vs RHE) along the preferred distal pathway is substantially less negative or comparable to many previously reported effective electrocatalysts for NRR, such as single W atom-doped g-C 3 N 4 (−0.35 V vs RHE), 24 Wsupported CN (−0.34 vs RHE), 70 Mo-based two-dimensional metal−organic framework (−0.34 V vs RHE), 23 single Modoped two-dimensional porphyrin sheet (−0.58 V vs RHE), 9 Ru dimer-supported graphyne monolayer (−0.43 V vs RHE), 71 Mo-doped g-GaN monolayer (−0.33 V vs RHE), 3 Mo-based phthalocyanine COF (−0.28 V vs RHE), 1 Modoped phthalocyanine monolayer (−0.70V vs RHE), 67 Co dimer-anchored graphdiyne monolayer (−0.43 V vs RHE), 72 Mo-supported defective BN (−0.35 V vs RHE), 59 and Fe/Mnanchored nitrogen-doped graphene (−0.37 V vs RHE). 69 To verify that there are no large kinetic barriers for the NRR on Mo-salphenCOF along the most favored distal pathway, we studied the kinetics for conversion of *NH 2 to *NH 3 , which is known to be the most thermodynamically uphill process and thus more probable to show the highest barrier.…”

Multiatom Catalysts for Energy‐Related Electrocatalysis

“…MACs have been predicted to show higher catalytic activity and selectivity toward NRR due to the synergetic effects between adjacent metal atoms, higher metal loading, and versatile active sites, which can feasibly tune the adsorption of N 2 molecule and intermediates. Theoretical investigations based on DFT computations have screened out promising MACs composed of either heteronuclear atoms or homonuclear atoms supported on various substrates, such as graphene and graphene oxide, [ 87–89 ] MoS 2 , [ 90 ] graphdiyne, [ 17,91 ] carbon nitrides (C 3 N 4 , [ 51,92 ] C 2 N, [ 93,94 ] etc.) and others.…”

g‐C3N4‐Supported Metal‐Pair Catalysts toward Efficient Electrocatalytic Nitrogen Reduction: A Computational Evaluation

“…In like manner, metal-pair catalysts (MPCs), or called double-atom catalysts, which are metal pairs anchored on substrate materials, can offer a larger space for heterogeneous catalyst optimization. For example, recently, Ru 2 N 6 @graphene, [31] Mo 2 @C 2 N, [32] Mn 2 @C 2 N, [33] Fe 2 @g-C 2 N, [34] Co 2 @graphdiyne, [35] and Ru 2 @graphyne [36] have been reported to display more excellent eNRR performance than their single-atom counterparts by tuning more flexibly the adsorption properties of the targeted intermediates. The MPCs are even superior to the triple-atom counterparts because the later could be unable to effectively capture and activate N 2 due to the relative higher coordination of metal atoms.…”