Cu1‐Fe Dual Sites for Superior Neutral Ammonia Electrosynthesis from Nitrate

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(31)

Published: May 21, 2024

Abstract The electrochemical nitrate reduction reaction (NO 3 RR) is able to convert − ) into reusable ammonia (NH ), offering a green treatment and resource utilization strategy of wastewater synthesis. conversion NO NH undergoes water dissociation generate active hydrogen atoms nitrogen‐containing intermediates hydrogenation tandemly. two relay processes compete for the same sites, especially under pH‐neutral condition, resulting in suboptimal efficiency selectivity electrosynthesis from . Herein, we constructed Cu 1 ‐Fe dual‐site catalyst by anchoring single on amorphous iron oxide shell nanoscale zero‐valent (nZVI) RR, achieving an impressive removal 94.8 % 99.2 neutral pH concentration 50 mg L −1 −N conditions, greatly surpassing performance nZVI counterpart. This superior can be attributed synergistic effect enhanced adsorption Fe sites strengthened activation single‐atom decreasing energy barrier rate‐determining step *NO‐to‐*NOH. work develops novel fabricating catalysts enhance , presents environmentally sustainable approach treatment.

Language: Английский

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Enhancing Compatibility of Two‐Step Tandem Catalytic Nitrate Reduction to Ammonia Over P‐Cu/Co(OH)₂

Advanced Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 11, 2024

Abstract Electrochemical nitrate reduction reaction (NO 3 RR) is a promising approach to realize ammonia generation and wastewater treatment. However, the transformation from NO − NH involves multiple proton‐coupled electron transfer processes by‐products 2 , H etc.), making high selectivity challenge. Herein, two‐phase nanoflower P‐Cu/Co(OH) electrocatalyst consisting of P‐Cu clusters P‐Co(OH) nanosheets designed match two‐step tandem process ) more compatible, avoiding excessive accumulation optimizing whole reaction. Focusing on initial 2e process, inhibited * desorption Cu sites in gives rise appropriate released electrolyte. Subsequently, exhibits superior capacity for trapping transforming desorbed during latter 6e due thermodynamic advantage contributions active hydrogen. In 1 m KOH + 0.1 leads yield rate 42.63 mg h cm Faradaic efficiency 97.04% at −0.4 V versus reversible hydrogen electrode. Such well‐matched achieves remarkable synthesis performance perspective catalytic reaction, offering novel guideline design RR electrocatalysts.

Language: Английский

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Atomically Dispersed Co–P Moieties via Direct Thermal Exfoliation for Alkaline Hydrogen Electrosynthesis

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

Published: Jan. 25, 2025

The development of highly active and stable cathodes in alkaline solutions is crucial for promoting the commercialization anion exchange membrane (AEM) electrolyzers, yet it remains a significant challenge. Herein, we synthesized atomically dispersed CoP4 moieties (CoP4–SSC) immobilized on ultrathin carbon nanosheets via phosphidation exfoliation strategy at medium temperature. thermodynamic formation process Co–P was elucidated using X-ray absorption spectroscopy (XAS) theoretical calculations. Remarkably, resulting CoP4–SSC electrocatalyst exhibited outstanding activity hydrogen evolution, with low overpotential 52 mV 10 mA cm–2 turnover frequency up to 23.83 s–1. Moreover, AEM electrolyzer fabricated achieved current density 1 A under an applied voltage only 1.94 V, showing negligible degradation after 500 h continuous electrocatalysis. series operando characterizations functional theory calculations revealed that formed nanointerface [P-*H···H2O*-Co], which facilitates water dissociation during Volmer–Heyrovsky pathway.

Language: Английский

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Interfacial Water Regulation for Nitrate Electroreduction to Ammonia at Ultralow Overpotentials

Advanced Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 8, 2025

Abstract Nitrate electroreduction is promising for achieving effluent waste‐water treatment and ammonia production with respect to the global nitrogen balance. However, due impeded hydrogenation process, high overpotentials need be surmounted during nitrate electroreduction, causing intensive energy consumption. Herein, a hydroxide regulation strategy developed optimize interfacial H 2 O behavior accelerating conversion of at ultralow overpotentials. The well‐designed Ru─Ni(OH) electrocatalyst shows remarkable efficiency 44.6% +0.1 V versus RHE nearly 100% Faradaic NH 3 synthesis 0 RHE. In situ characterizations theoretical calculations indicate that Ni(OH) can regulate structure promoted dissociation process contribute spontaneous hydrogen spillover boosting NO − Ru sites. Furthermore, assembled rechargeable Zn‐NO /ethanol battery system exhibits an outstanding long‐term cycling stability charge–discharge tests high‐value‐added ammonium acetate, showing great potential simultaneously removal, conversion, chemical synthesis. This work not only provide guidance in extensive reactions but also inspire design novel hybrid flow multiple functions.

Language: Английский

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Subnanometric Nickel Phosphide Heteroclusters with Highly Active Ni^δ+–P^δ− Pairs for Nitrate Reduction toward Ammonia

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

Published: March 26, 2025

The development of efficient electrocatalysts for the neutral nitrate reduction reaction (NO3–RR) toward ammonia (NH3) is essential to address environmental issues caused by NO3– but remains considerably challenging owing sluggish kinetics NO3–RR in media. Herein, we report subnanometric heteroclusters with strongly coupled nickel–phosphorus (Ni–P) dual-active sites as boost NO3–RR. Experimental and theoretical results reveal that feature Ni–P promotes electron transfer from Ni P, generating Niδ+–Pδ− active pairs, which Niδ+ species are highly Pδ− tunes interfacial water hydrogen bonding network promote dissociation step accelerate proton during Consequently, NO3–RR, exhibit a large NH3 yield rate 0.61 mmol h–1 cm–2 at −0.8 V versus reversible electrode, 2.8- 3.3-fold larger than those on nanoparticles clusters, respectively, generated exists NH4+ electrolytes. This study offers an approach boosting electrocatalytic reactions multiple intermediates designing sites.

Language: Английский

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Unveiling Ionized Interfacial Water‐Induced Localized H* Enrichment for Electrocatalytic Nitrate Reduction

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 64(1)

Published: Sept. 4, 2024

Electrocatalytic nitrate reduction reaction (NO

Language: Английский

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Periodic Adjacent Pd‐Fe Pair Sites for Enhanced Nitrate Electroreduction to Ammonia via Accelerating Proton Relay

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: 14(33)

Published: May 29, 2024

Abstract Recently, bimetallic nanoparticles (NPs) are promising for driving nitrate (NO 3 − ) reduction reaction RR) to produce ammonia (NH due their multiple active sites and electron redistribution via strong metal–metal interaction. However, the quantitatively determining atomic configuration of revealing respective roles in NO RR process still challenged. Herein, atomically ordered PdFe L1 2 intermetallic NPs into mesoporous carbon nanofibers (O‐PdFe ‐mCNFs) is reported as an efficient catalyst NH synthesis. Compared face‐centered cubic one, O‐PdFe ‐mCNFs demonstrate a high removal 98.3% within 270 min with large yield rate 1014.2 µmol h −1 cm −2 . The detailed situ theoretical analysis reveals that performance attributed synergetic effect from periodic adjacent Pd‐Fe pair at (110) facet accelerating proton relay, where Fe show preferable stabilization nitrogen−oxygen (*NO) intermediates while Pd serve reservoir *NO hydrogenation. Moreover, d ‐ orbital hybridization tunes ‐band center alloy effectively modulates adsorption energy *NO. This electrocatalyst design offers new avenue developing highly multifunctional catalysts.

Language: Английский

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Atomic Cobalt Metal Centers with Asymmetric N/B‐Coordination for Promoting Oxygen Reduction Reaction

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: 34(48)

Published: July 5, 2024

Abstract Cobalt single atom catalysts (SACs) have exhibited promising performance in both the oxygen reduction reaction (ORR) and evolution (OER), positioning them as potential dual‐functional for Zn‐air battery. However, long‐standing challenge lies achieving satisfactory dual‐functionality stability of these SACs. In this study, to optimize 4e ‒ ORR performance, boron (B) atoms are employed with low electronegativity regulate structure Co–N–C catalytic center. This resulted formation an asymmetrically coordinated Co metal center catalyst (Co‐N 3 B). Compared Co‐N 4 , B lower free energy stronger adsorption toward * O species, effectively suppressing 2e pathway at cobalt site preventing corrosion induced by hydrogen peroxide (H 2 ) reactions, thereby enhancing stability. situ attenuated total reflectance surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) further validated excellent interaction between active centers intermediates. Furthermore, self‐made rechargeable zinc‐air battery demonstrated remarkable discharge peak power density (≈253 mW cm ‒2 ), (≈819 mAh g ‒1 cyclic exceeding 110 h. study provides new insights into constructing atomic‐level precision offers strong references practical applications storage convension electrocatalysts.

Language: Английский

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Boosting nitrate electroreduction to ammonia on atomic Ru-Co pair sites in hollow spinels

Applied Catalysis B Environment and Energy, Journal Year: 2024, Volume and Issue: 358, P. 124387 - 124387

Published: July 9, 2024

Language: Английский

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Core–Shell Co‐Co_xP Nanoparticle‐Embedded N‐Doped Carbon Nanowhiskers Hollow Sphere for Efficient Oxygen Evolution Electrocatalysis

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: July 26, 2024

Abstract The development of efficient oxygen evolution reaction (OER) electrocatalysts is critical to overcome the efficiency bottleneck in hydrogen generation via water electrolysis. Hollow nanostructured materials have emerged as a hot topic for electrocatalysis research because their advantages, including abundant active sites, large contact area between catalyst and electrolyte, short transmission path. As highly stable OER electrocatalysts, cobalt‐based attracted more attention. In this work, cobalt metal/cobalt phosphides/nitrogen‐doped carbon composites (Co‐Co x P/NC) with hierarchical hollow structure are designed by using ZIF‐67 microspheres precursors. By coating ZIF‐8 on surface further carbonizing, nanowhiskers successfully formed spheres under catalytic effect Co nanoparticles at high temperature. subsequent phosphating process, solid nanocrystalline particles transformed into core–shell CoP 2 P account Kirkendall effect. Through optimization microstructure material synergistic transition metal, metal phosphide, nitrogen doping, overpotential optimal only 287 mV 10 mA cm −2 current density 1 m KOH.

Language: Английский

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