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Electrocatalytic Nitrogen Reduction on a Molybdenum Complex Bearing a PNP Pincer Ligand.

ABSTRACT: Electrocatalytic nitrogen reduction (N₂R) mediated by well-defined molecular catalysts is poorly developed by comparison with other reductive electrocatalytic transformations. Herein, we explore the viability of electrocatalytic N₂R mediated by a molecular Mo-PNP complex. A careful choice of acid, electrode material, and electrolyte mitigates electrode-mediated HER under direct electrolysis and affords up to 11.7 equiv of NH₃ (Faradaic efficiency < 43%) at -1.89 V versus Fc⁺/Fc. The addition of a proton-coupled electron transfer (PCET) mediator has no effect. The data presented are rationalized by an initial electron transfer (ET) that sets the applied bias needed and further reveal an important impact of [Mo] concentration, thereby pointing to potential bimolecular steps (e.g., N₂ splitting) as previously proposed during chemically driven N₂R catalysis. Finally, facile reductive protonation of [Mo(N)Br(^HPNP)] with pyridinium acids is demonstrated.

SUBMITTER: Ibrahim AF

PROVIDER: S-EPMC10939127 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature

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Electrocatalytic Nitrogen Reduction on a Molybdenum Complex Bearing a PNP Pincer Ligand.

Ibrahim Ammar F AF Garrido-Barros Pablo P Peters Jonas C JC

ACS catalysis 20221212 1

Electrocatalytic nitrogen reduction (N2R) mediated by well-defined molecular catalysts is poorly developed by comparison with other reductive electrocatalytic transformations. Herein, we explore the viability of electrocatalytic N2R mediated by a molecular Mo-PNP complex. A careful choice of acid, electrode material, and electrolyte mitigates electrode-mediated HER under direct electrolysis and affords up to 11.7 equiv of NH3 (Faradaic efficiency < 43%) at -1.89 ...[more]

PMID: 38487038

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