Revealing catalyst restructuring and composition during nitrate electroreduction through correlated operando microscopy and spectroscopy

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

Published: Jan. 24, 2025

Abstract Electrocatalysts alter their structure and composition during reaction, which can in turn create new active/selective phases. Identifying these changes is crucial for determining how morphology controls catalytic properties but the mechanisms by operating conditions shape catalyst’s working state are not yet fully understood. In this study, we show using correlated operando microscopy spectroscopy that as well-defined Cu 2 O cubes evolve under electrochemical nitrate reduction reaction conditions, distinct catalyst motifs formed depending on applied potential chemical environment. By further matching timescales of morphological observed via liquid cell transmission electron with time-resolved information obtained from soft X-ray microscopy, hard absorption Raman spectroscopy, reveal be kinetically stabilized alongside metallic copper extended durations moderately reductive due to surface hydroxide formation. Finally, rationalize interaction between electrolyte influences ammonia selectivity.

Language: Английский

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Tandem Active Sites in Cu/Mo‐WO₃ Electrocatalysts for Efficient Electrocatalytic Nitrate Reduction to Ammonia

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

Published: Jan. 5, 2025

Abstract Electrocatalytic NO 3 − reduction to NH is a promising technique for both ammonia synthesis and nitrate wastewater treatment. However, this conversion involves tandem processes of H 2 O dissociation hydrogenation, leading inferior Faraday efficiency (FE) yield rate. Herein, catalyst by anchoring atomically dispersed Cu species on Mo‐doped WO (Cu 5 /Mo 0.6 ‐WO ) the RR constructed, which achieves superior FE N 98.6% rate 26.25 mg h −1 cat at −0.7 V (vs RHE) in alkaline media, greatly exceeding performance Mo /WO counterparts. Systematic electrochemical measurement results reveal that promoted activation sites, accompanying accelerated water producing active hydrogens are responsible performance. In situ infrared spectroscopy theoretical calculation further demonstrate sites accelerate , dopant activates adjacent resulting decreased energy barrier * stepwise hydrogenation processes, making thermodynamically favorable. This work demonstrates critical role atomic level enhancing electrocatalytic paving feasible avenue developing high‐performance electrocatalysts.

Language: Английский

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Ammonia electrosynthesis from nitrate using a stable amorphous/crystalline dual-phase Cu catalyst

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 21, 2025

Renewable energy-driven electrocatalytic nitrate reduction reaction presents a low-carbon and sustainable route for ammonia synthesis under mild conditions. Yet, the practical application of this process is currently hindered by unsatisfactory activity long-term stability. Herein we achieve high-rate electrosynthesis using stable amorphous/crystalline dual-phase Cu catalyst. The partial current density formation rate reach 3.33 ± 0.005 A cm-2 15.5 0.02 mmol h-1 at low cell voltage 2.6 0.01 V, respectively. Remarkably, catalyst can maintain production with Faradaic efficiency around 90% high 1.5 up to 300 h. scale-up demonstration an electrode size 100 cm2 achieves as 11.9 0.5 g total 160 A. impressive performance ascribed presence amorphous domains which promote adsorption hydrogenation nitrogen-containing intermediates, thus improving kinetics formation. This work underscores importance stabilizing metastable structures reactivity

Language: Английский

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Capping Effect on High‐Active Nucleated‐Zn Toward Hydrogen Evolution‐Free Zn Metal Batteries

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

Published: Jan. 5, 2025

Abstract Aqueous Zn‐ion batteries are promising for large‐scale energy storage due to low cost and high safety. However, aqueous electrolyte induces severe side reactions at Zn anode, especially hydrogen evolution reaction (HER). Herein, it is first revealed that the freshly nucleated‐Zn (FN‐Zn) atoms during plating process show higher reactivity stronger adsorption of proton than metallic anode by X‐ray absorption near edge structure (XANES) corresponding extended fine (EXAFS), density functional theory simulations, promoting decomposition H 2 O. Then, a universal effective capping effect strategy proposed alleviate HER electrostatically shielding FN‐Zn activity. Specifically, sodium benzenesulfonate (SBS) selected as typical example screening comparing series additives, in which sulfonate group with coordination can be preferentially capped on reduce its reactivity. Consequently, symmetrical cell SBS not only generates negligible amounts situ electrochemical‐gas chromatography but also up 2550 h 1 mA cm −2 . More importantly, HER‐free verified coin full cells exhibiting capacity retention of≈87.1% after 1000 cycles large‐area (4 × 6 ) pouch desired performance.

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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Electrocatalytic reduction of nitrogen oxide species to ammonia

Chem, Journal Year: 2024, Volume and Issue: 10(10), P. 2963 - 2986

Published: Aug. 12, 2024

Language: Английский

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Hydration‐effect Boosted Active Hydrogen Facilitates Neutral Ammonia Electrosynthesis from Nitrate Reduction

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

Published: Oct. 8, 2024

Abstract Electrocatalytic nitrate reduction to ammonia (NO 3 RR) in a neutral medium is green and effective strategy for treating pollution meanwhile producing ammonia. However, the insufficient active hydrogen (H * ) on catalyst surface resulting from sluggish Volmer step 2 O → H + OH − ), competitive evolution reaction (HER) caused by coupling severely restrict enhancement of NO RR activity. Herein, hydration‐effect boosted ‐rich facilitating electrosynthesis proposed. The introduction hydration‐effect‐promoting element aluminum into copper‐based forming CuAlO , which adjusts electron density distribution system, significantly promotes generation medium. Moreover, rapid charge transfer at CuO/CuAlO interface facilitates kinetics diffusion. More importantly, Al weakens overly strong adsorption intermediates CuO, thereby accelerating hydrogenation process suppressing HER. Thus, under conditions, reached Faradaic efficiency an yield as high 97.81 ± 1.94% 10.21 0.64 mg h −1 cm −2 −1.0 V versus RHE toward RR.

Language: Английский

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In Situ Spectroscopic Probing of the Hydroxylamine Pathway of Electrocatalytic Nitrate Reduction on Iron‐Oxy‐Hydroxide

Small, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 14, 2025

Abstract Crystalline γ‐FeO(OH) dominantly possessing ─ OH terminals (𝛾‐FeO(OH) c ), polycrystalline containing multiple O, OH, and Fe pc α‐Fe 2 O 3 majorly surface are used as electrocatalysts to study the effect of on electrocatalytic nitrate reduction reaction (eNO RR) selectivity stabilization intermediates. Brunauer‐Emmett‐Teller analysis electrochemically determined area suggest a high active 117.79 m g −1 (ECSA: 0.211 cm ) for 𝛾‐FeO(OH) maximizing accessibility adsorption exhibiting selective eNO RR NH at pH 7 with yield rate 18.326 mg h −2 , >85% Faradaic efficiency (FE), least nine‐times catalyst‐recyclability. 15 N‐ D‐labeling combined in situ IR Raman studies validate ions generation nitrite hydroxyl amine A kinetic isotope (KIE) value 2.1 indicates H proton source proton‐coupled electron transfer rate‐limiting step. The rotating‐ring disk electrochemical (RRDE) subsequent Koutecký‐Levich reveal electron‐transfer constant (k) 2e‐ is 5.7 × 10 −6 s . This provides direct evidence formation dominant pathway γ‐FeO(OH).

Language: Английский

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FeIr Alloy Optimizes the Trade‐Off Between Nitrate Reduction and Active Hydrogen Generation for Efficient Electro‐Synthesis of Ammonia in Neutral Media

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

Published: Feb. 10, 2025

Abstract Electrochemically promoted nitrate reduction reaction (NITRR) holds great potential for the “green” synthesis of ammonia (NH 3 ). However, NITRR in neutral media, though close to practical scenario, is often limited by an insufficient supply active hydrogen (*H) due sluggish water cleavage. In this work, it demonstrated that a bimetallic alloy FeIr can optimize trade‐off between and *H formation media. As result, exhibits excellent catalytic performance toward with Faradaic efficiency NH up 97.3% high yield rate 11.67 mg h −1 cm −2 at low working −0.6 V (versus reversible electrode (RHE)), surpassing monometallic catalysts as well majority Fe‐based state‐of‐the‐art. It also found displays remarkable electron rearrangement hetero‐atoms their significant orbital hybridization, which benefits not only but process. Moreover, coupling FeIr‐based methanol oxidation (MOR) results sustainable productions formate combined FE nearly 200% cell‐voltage 2 V. This work thus demonstrates promising strategy designing efficient NITRR.

Language: Английский

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Controlling electrocatalytic nitrate reduction efficiency by utilizing dπ–pπ interactions in parallel stacking molecular systems

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

The orientation of β-CuPc favours the overlap central Cu with N parallel molecules, which is reason behind high electrical conductivity and selectivity in NH 3 production via nitrate reduction, impossible other polymorphs.

Language: Английский

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