Multiple Reaction Pathways for Oxygen Evolution as a Key Factor for the Catalytic Activity of Nickel–Iron (Oxy)Hydroxides

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 15, 2025

We present a comprehensive theoretical study, using state-of-the-art density functional theory simulations, of the structural and electrochemical properties amorphous pristine iron-doped nickel–(oxy)hydroxide catalyst films for water oxidation in alkaline solutions, referred to as NiCat Fe:NiCat. Our simulations accurately capture changes locally ordered units, reported by X-ray absorption spectroscopy, when are activated exposure positive potential. emphasize critical role proton-coupled electron transfer reversible Ni(II) Ni(III/IV) during this activation. After establishing models Fe:NiCat consistent with experimental data, we used them explore atomistic mechanism oxygen evolution reaction (OER), which is triggered once applied potential exceeds overpotential required production. quantitatively compared seven OER pathways applicable both adsorbate (AEM) lattice-oxygen-mediated (LOM) families, elucidating how iron significantly enhances catalytic activity NiCat. findings suggest that simple metal–oxygen–metal motifs, common on surface crystalline metal (oxy)hydroxide films, can promote AEM LOM mechanisms under typical conditions. Furthermore, propose elusive lies distinct behavior Ni(IV)–O Fe(IV)–O bonds key intermediates preceding formation O–O bond, Fe ions lowering needed form these across investigated pathways.

Language: Английский

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Exchange Coupling Determines Metal-Dependent Efficiency for Iron- and Cobalt-Catalyzed Photochemical CO₂ Reduction

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(14), P. 8484 - 8493

Published: July 1, 2022

Catalysts promoting multielectron charge delocalization offer selectivity for the CO2 reduction reaction (CO2RR) over competing hydrogen evolution reaction. Here, we show metal–ligand exchange coupling as an example of that can determine efficiency photocatalytic CO2RR. A comparative evaluation iron and cobalt complexes supported by redox-active ligand tpyPY2Me establishes two-electron [Co(tpyPY2Me)]2+ ([Co]2+) occurs at potentials 770 mV more negative than [Fe(tpyPY2Me)]2+ ([Fe]2+) analogue maximizing in latter compound. The positive shift potential promoted drives [Fe]2+ to be among most active selective molecular catalysts photochemical CO2RR reported date, maintaining up 99% CO product with total turnover numbers (TONs) initial frequencies exceeding 30,000 900 min–1, respectively. In contrast, [Co]2+ shows much lower activity, reaching only ca. 600 TON 83% under similar conditions accompanied rapid catalyst decomposition. spin density plots reduced [Co]0 complex implicate a paramagnetic open-shell doublet ground state compared diamagnetic singlet [Fe]0, rationalizing observed from [M]2+ species lowered relative its congener. This work emphasizes contributions effective provides starting point broader incorporation this strategy design.

Language: Английский

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Sodium–gallium alloy layer for fast and reversible sodium deposition

SusMat, Journal Year: 2022, Volume and Issue: 2(6), P. 699 - 707

Published: Nov. 7, 2022

Abstract Sodium metal has been regarded as the potential alternative for batteries owing to its advantages of high theoretical capacity and abundant reserves. Nevertheless, propagation Na dendrites can boost interfacial instability metal, retarding practical implementation. Thus, Na–Ga alloy layer is designed fabricated by in situ rolling Ga on surface metal. This possesses good sodiophilicity, which effectively protect favor uniform + deposition, obtaining inhibition growth. Consequently, symmetric cells assembled alloy‐layer protected electrodes (NGAL‐Na||NGAL‐Na) have a long lifetime (468 h) even under plating/stripping 6 mAh cm −2 carbonate electrolyte. The full battery NGAL‐Na||Na 3 V 2 (PO 4 ) able sustain an excellent rate capability 100 g −1 after 500 cycles at 10 C ambient temperature. work provides new route prevent anodes from severe dendrite growth, paves way toward safer stable‐performing metal‐based rechargeable batteries.

Language: Английский

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Alternative Energy Carriers: Unique Interfaces for Electrochemical Hydrogenic Transformations

Advanced Energy Materials, Journal Year: 2023, Volume and Issue: 13(14)

Published: March 1, 2023

Abstract The shift toward renewable energy generation sources, characterized by their non‐carbon emitting but variable nature, has spurred significant innovation in storage technologies. Advancements foundational understanding from investments basic science and clever engineering solutions, coupled with increasing industrial adoption, have resulted a notable reduction the cost of storing electricity sources. These developments paved way for exploration new innovative forms that deviate traditional In this perspective, it is posited progress made research over recent years opened door to development carriers technologies are yet be realized. To illustrate concept, examples alternative provided within context unique electrochemical interfaces hydrogenic transformations. properties these systems can leveraged ways not imagined, creating possibilities storage. A perspective on challenges each interface as well general outlook advancement carrier provided.

Language: Английский

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Selectively converting CO2 to HCOOH on Cu-alloys integrated in hematite-driven artificial photosynthetic cells

Journal of Energy Chemistry, Journal Year: 2023, Volume and Issue: 79, P. 601 - 610

Published: Jan. 20, 2023

Language: Английский

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