Spontaneous N2 formation by a diruthenium complex enables electrocatalytic and aerobic oxidation of ammonia

Trenerry, Michael; Wallen, Christian M.; Brown, Tristan R.; Park, Sungho V.; Berry, John F.

doi:10.1038/s41557-021-00797-w

Cited by 58 publications

(64 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reduction of a diruthenium pyridonate complex by amine has also been reported. 51 A plausible simplified mechanism for this process is outlined in Scheme 6. First, transamination with pyrrolidine produces another V(IV) bis(amido) complex A.…”

Section: Reduction Of Vanadium(iv) Pyridonates With Alkylaminesmentioning

confidence: 99%

Vanadium pyridonates: dimerization, redox behaviour, and metal–ligand cooperativity

2022

View full text Add to dashboard Cite

show abstract

Section: Reduction Of Vanadium(iv) Pyridonates With Alkylaminesmentioning

confidence: 99%

Vanadium pyridonates: dimerization, redox behaviour, and metal–ligand cooperativity

2022

View full text Add to dashboard Cite

show abstract

“…Coupling this anodic reaction with oxygen reduction in MeCN (E°ORR = 0.233 V vs Fc +/0 ) requires a maximum overpotential of +1.18 V to generate useful energy in a direct ammonia fuel cell (DAFC). 16 Alternatively, ammonia electrolysis generates N2 and H2 (Figure 1b), the later for potential use in H2 fuel cells once scrubbed from any remaining ammonia. [17][18] Figure 1.…”

Section: Introductionmentioning

confidence: 99%

“…This dinuclear ruthenium species mediates electrocatalytic oxidation of ammonia with an onset potential at −255 mV, generating N2 and H2 via controlled potential electrolysis (CPE) at 0.0 V vs Fc 0/+ . 16 Aryloxy radicals ArO• may be used to chemically oxidize ammonia bound to a ruthenium porphyrin complex (porph)Ru(NH3). 11 Sustainability considerations motivate the use of earthabundant transition metals for ammonia oxidation.…”

Section: Introductionmentioning

confidence: 99%

“…[4][5][6][7][8] Examples of homogeneous catalysts are attracting increasing attention. [9][10][11][12][13][14][15][16] Homogeneous catalysts offer synthetic control over steric and electronic properties of the active site along with a suite of molecular tools to understand the fundamental chemistry involved through detailed structural, spectroscopic and mechanistic studies. 7 Ammonia oxidation is a six-electron process that generates nitrogen gas (N2) directly from ammonia.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electrocatalytic Ammonia Oxidation by a Low Coordinate Copper Complex

Ahmed

Boroujeni

Ghosh

et al. 2022

Preprint

View full text Add to dashboard Cite

Molecular catalysts for ammonia oxidation to dinitrogen represent enabling components to utilize ammonia as a fuel and/or source of hydrogen. Ammonia oxidation requires not only the breaking of multiple strong N-H bonds, but also controlled N-N bond formation. We report a novel β-diketiminato copper complex [iPr2NNF6]Cu-NH3 ([Cu(I)]-NH3 (2)) as a robust electrocatalyst for NH3 oxidation in acetonitrile under homogeneous conditions. Complex 2 operates at a moderate overpotential (700 mV) with a TOFmax = 940 h-1 as determined from CV data in 1.3 M NH3 MeCN solvent. Prolonged (>5 h) controlled potential electrolysis (CPE) reveals the stability and robustness of the catalyst under electrocatalytic conditions. Detailed mechanistic investigations indicate that electrochemical oxidation of [Cu(I)]-NH3 forms {[Cu(II)]-NH3}+ (4) which undergoes deprotonation by excess NH3 to form reactive copper(II)-amide [Cu(II)]-NH2 (6) unstable towards N-N bond formation to give the dinuclear hydrazine complex [Cu(I)]2(mu-N2H4). Electrochemical studies reveal that the bisammine complex [Cu(I)](NH3)2 (7) forms at high ammonia concentration as part of the {[Cu(II)](NH3)2}+/[Cu(I)](NH3)2 redox couple that is electrocatalytically inactive. DFT analysis reveals a much higher thermodynamic barrier for deprotonation of {[Cu(II)](NH3)2}+ (8) by NH3 to give the four-coordinate copper(II) amide [Cu(II)](NH2)(NH3) (9) (dG = 31.7 kcal/mol) as compared to deprotonation of the three coordinate {[Cu(II)]-NH3}+ by NH3 to provide the reactive three coordinate parent amide [Cu(II)]-NH2 (dG = 18.1 kcal/mol) susceptible to N-N coupling to form [Cu(I)]2(mu-N2H4) (dG = -11.8 kcal/mol).

show abstract

“…16,17 The rich redox characteristics of Ru 2 compounds further enable a broad range of applications as wires in nanojunctions, 18,19 spin-chains, 20 and catalytic activation of small molecules. [21][22][23] More recently, Ru 2 (ap) 4 (Ar) type compounds (Ar = aryl) were prepared, 24 and their capacity in binding small linear ligands such as CO, CN À and C 2 H À at the axial site trans-to Ar was demonstrated. 25 Interested in expanding this chemistry to investigate bridging arylenes, we report herein the formation and characterization of [Ru 2 (ap) 4 ] 2 (m-1,4-C 6 H 4 ) (1, Scheme 1) and its derivative [(NC)Ru 2 (ap) 4 ] 2 (m-1,4-C 6 H 4 ) (2, Scheme 1), the unambiguous evidence of strong intermetallic coupling across the phenylene bridge through the SEC study of [2] + , and companion DFT and TD-DFT analyses.…”

mentioning

confidence: 99%