Conversion of Dinitrogen to Ammonia by FeN₃-Embedded Graphene

Abstract

Nitrogen fixation is one of the most important issues but a long-standing challenge in chemistry. Here, we propose FeN3-embedded graphene as the catalyst for nitrogen fixation from first-principles calculations. Results show that in view of the chemical coordination, the FeN3 center is highly spin-polarized with a localized magnetic moment substantially to promote N2 adsorption and activate its inert N-N triple bond. The synergy between the graphene and FeN3 equips the system with novel features for the catalytic conversion of the activated N2 into NH3 via a six-proton and six-electron process, following three possible reaction pathways at room temperature. Our findings provide a rational paradigm for catalytic nitrogen fixation that would be conducive to ammonia production.

Transition Metal‐dinitrogen Complex Embedded Graphene for Nitrogen Reduction Reaction

“…The whole catalytic process needs six protons and six electrons, which follows the three possible pathways: distal, alternating and enzyme mechanisms. [2,6,[25][26][27][28][29] The manner of nitrogen molecule absorbed on the catalytic active site is the influence factor of NRR pathway. Both the distal and alternating mechanisms are following the "end-on" pattern of nitrogen molecule absorption, while the enzyme mechanism is along with the "side on" pattern.…”

“…Since the transition metal-dinitrogen (TMN 4 ) complex have been synthesized and regarded as the effective catalysts for converting nitrogen to ammonia, a number of TM-based electrocatalysts have been synthesized and reported. [28,[32][33][34] William A. Goddard III group used quantum mechanics to predict reaction mechanisms and kinetics for ammonia synthesis on Fe(111) surface. [32] Luo and co-worker found that the FeN 3 center was highly spin-polarized with a localized magnetic moment substantially to promote N 2 adsorption and activate its inert NÀ N triple bond.…”

General synthesis and definitive structural identification of MN4C4 single-atom catalysts with tunable electrocatalytic activities

“…In particular, Fe-based M-N-Cs have been extensively studied as electrocatalysts towards the oxygen reduction reaction (ORR) with demonstrated activity and stability approaching those of commercial Pt/C catalysts 20,21 . In addition, as suggested by numerous theoretical studies, M-N-Cs are promising candidates for catalysing a wide range of electrochemical processes, such as hydrogen reduction/oxidation 22 , CO 2 /CO reduction 23 and N 2 reduction 24 . A significant advantage of SACs is that the well-defined single atomic site could allow precise understanding of the catalytic reaction pathway, and rational design of targeted catalysts with tailored activity (in a manner similar to homogeneous catalyst design).…”

“…A significant advantage of SACs is that the well-defined single atomic site could allow precise understanding of the catalytic reaction pathway, and rational design of targeted catalysts with tailored activity (in a manner similar to homogeneous catalyst design). However, this perceived advantage has been investigated theoretically 23,24 , but has not yet been demonstrated experimentally in M-N-Cs, largely because existing M-N-Cs were generally obtained through pyrolysis of metal-, nitrogen-and carbon-containing molecular or polymeric precursors and the as-synthesized materials Articles Nature Catalysis are typically highly heterogeneous, concurrently containing single atomic metals along with crystalline particles, and crystalline and amorphous carbon [25][26][27][28] . Such structural and compositional heterogeneity poses a key obstacle to unambiguously identifying the exact atomistic structure of the active sites and to further establishing a definitive correlation with the catalytic properties that can guide the subsequent design of future generations of SACs.…”

Exploring an effective oxygen reduction reaction catalyst via 4e− process based on waved-graphene

“…For pure WG, it can proceed smoothly with the onset potential 0.6 V. However, for the N-doped-WG, it must overcome 1. [45], N 2 [46,47], NO [48], CO [49][50], etc. We also hope the results can provide necessary mechanism information for future experiments on WG for ORR.…”