Enabled Efficient Ammonia Synthesis and Energy Supply in a Zinc–Nitrate Battery System by Separating Nitrate Reduction Process into Two Stages

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(13)

Published: Feb. 2, 2023

The aqueous electrocatalytic reduction of NO3- into NH3 (NitrRR) presents a sustainable route applicable to production and potentially energy storage. However, the NitrRR involves directly eight-electron transfer process generally required large overpotential (<-0.2 V versus reversible hydrogen electrode (vs. RHE)) reach optimal efficiency. Here, inspired by biological nitrate respiration, was separated two stages along [2+6]-electron pathway alleviate kinetic barrier. system employed Cu nanowire catalyst produces NO2- with current efficiencies 91.5 % 100 %, respectively at lower overpotentials (>+0.1 vs. RHE). high efficiency for such further explored in zinc-nitrate battery. This battery could be specified output voltage 0.70 V, an average density 566.7 Wh L-1 10 mA cm-2 power 14.1 mW , which is well beyond all previously reported similar concepts.

Language: Английский

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Breaking Local Charge Symmetry of Iron Single Atoms for Efficient Electrocatalytic Nitrate Reduction to Ammonia

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(39)

Published: July 22, 2023

The electrochemical conversion of nitrate pollutants into value-added ammonia is a feasible way to achieve artificial nitrogen cycle. However, the development electrocatalytic nitrate-to-ammonia reduction reaction (NO3- RR) has been hampered by high overpotential and low Faradaic efficiency. Here we develop an iron single-atom catalyst coordinated with phosphorus on hollow carbon polyhedron (denoted as Fe-N/P-C) NO3- RR electrocatalyst. Owing tuning effect atoms breaking local charge symmetry single-Fe-atom catalyst, it facilitates adsorption ions enrichment some key intermediates during process. Fe-N/P-C exhibits 90.3 % efficiency yield rate 17980 μg h-1 mgcat-1 , greatly outperforming reported Fe-based catalysts. Furthermore, operando SR-FTIR spectroscopy measurements reveal pathway based observed under different applied potentials durations. Density functional theory calculations demonstrate that optimized free energy ascribed asymmetric atomic interface configuration, which achieves optimal electron density distribution. This work demonstrates critical role atomic-level precision modulation heteroatom doping for RR, providing effective strategy improving catalytic performance single atom catalysts in reactions.

Language: Английский

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Emerging Applications, Developments, Prospects, and Challenges of Electrochemical Nitrate‐to‐Ammonia Conversion

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(29)

Published: April 23, 2023

Abstract Ammonia is not only an important feedstock for chemical industry but also a carbon‐free energy carrier and safe storage media hydrogen. Due to the advantages compared Haber–Bosch process, electrochemical NO 3 − ‐to‐NH conversion via nitrate reduction reaction (NO RR) received attention. Recently, “green hydrogen” generated from water electrolysis shows promise become future limited by safety of transportation. This review proposes can store renewable electric into NH , which potential solution solving puzzle Moreover, theoretical insights RR electrocatalyst design are discussed. Finally, challenges opportunities in this field elucidated. provides novel perspective accelerates development effective electrocatalysts conversion.

Language: Английский

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Boosting Electrocatalytic Nitrate Reduction to Ammonia via Promoting Water Dissociation

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(16), P. 10846 - 10854

Published: Aug. 2, 2023

Electrocatalytic nitrate reduction reaction (NO3–RR) opens opportunities for ammonia production. The sluggish kinetics of this multielectron and multiproton process has been regarded as the key issue. Herein, we report a Cu1Co5 alloy electrocatalytic NO3–RR to NH3. It achieves high current density (453 mA cm–2) Faradaic efficiency (96.2%) NH3 production at 0.075 V vs RHE, with half-cell energy 44.9%, higher than those Cu, Co, other Co-based alloys, is among highest value reported. We found that interaction between Cu Co reorganizes their electronic structure in alloys. NO3– adsorption switches spontaneous process, *NO → *N *NH *NH2 processes are promoted. Importantly, water dissociation concerted transformation N-species proven be rate-determining, which facilitated on sites essential enhanced NO3–RR. This inspires us strategy designing more efficient catalysts under alkaline condition by promoting H2O process.

Language: Английский

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Hexagonal Cobalt Nanosheets for High-Performance Electrocatalytic NO Reduction to NH₃

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(12), P. 6899 - 6904

Published: March 14, 2023

Electrocatalytic nitric oxide (NO) reduction not only provides an extremely promising strategy for ambient NH3 generation but also alleviates the artificially disrupted N-cycle balance. However, exploring efficient electrocatalysts to enhance NO electroreduction performance remains a significant challenge. Herein, hexagonal-close-packed Co nanosheet (hcp-Co) is prepared and exhibits high yield of 439.50 μmol cm-2 h-1 Faraday efficiency 72.58%, outperforming face-centered cubic phase (fcc-Co) most reported electrocatalysts. Through combination density functional theory calculations temperature-programmed desorption experiments, superior catalytic reaction (NORR) activity on hcp-Co can be attributed unique electron structures proton shuttle effect. A proof-of-concept device Zn-NO batteries using as cathode assembled shows power 4.66 mW cm-2, which in literature so far.

Language: Английский

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Electrochemical synthesis of ammonia from nitric oxide using a copper–tin alloy catalyst

Nature Energy, Journal Year: 2023, Volume and Issue: 8(11), P. 1273 - 1283

Published: Nov. 6, 2023

Language: Английский

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Direct Synthesis of Ammonia from Nitrate on Amorphous Graphene with Near 100% Efficiency

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(24)

Published: Feb. 17, 2023

Ammonia is an indispensable commodity in the agricultural and pharmaceutical industries. Direct nitrate-to-ammonia electroreduction a decentralized route yet challenged by competing side reactions. Most catalysts are metal-based, metal-free with high conversion activity rarely reported. Herein, it shown that amorphous graphene synthesized laser induction comprising strained disordered pentagons, hexagons, heptagons can electrocatalyze eight-electron reduction of NO3- to NH3 Faradaic efficiency ≈100% ammonia production rate 2859 µg cm-2 h-1 at -0.93 V versus reversible hydrogen electrode. X-ray pair-distribution function analysis electron microscopy reveal unique molecular features facilitate reduction. In situ Fourier transform infrared spectroscopy theoretical calculations establish critical role these stabilizing reaction intermediates via structural relaxation. The enhanced catalytic enables implementation flow electrolysis for on-demand synthesis release >70% selectivity, resulting significantly increased yields survival rates when applied plant cultivation. results this study show significant promise remediating nitrate-polluted water completing NOx cycle.

Language: Английский

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Potential-Induced Synthesis and Structural Identification of Oxide-Derived Cu Electrocatalysts for Selective Nitrate Reduction to Ammonia

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(11), P. 7529 - 7537

Published: May 19, 2023

Developing effective electrocatalysts for nitrate reduction to ammonia is paramount synthesis while addressing the water pollutant issue. Identifying active structure and its correlation with catalytic behavior during reaction process essential challenging rational design of advanced electrocatalysts. Herein, starting from Cu2O particles controllable crystal facets, electrochemically reconstituted Cu/Cu2O was fabricated as a suitable system, relationship between chemical state copper product selectivity in studied. At −0.9 V versus reversible hydrogen electrode, oxide-derived Cu0 (OD-Cu) cube achieved high Faradaic efficiency 93.9% productivity up 219.8 μmol h–1 cm–2, surpassing those most Cu-based catalysts. In situ Raman analysis, well-designed pulsed electrolysis experiments, theoretical calculations showed that preferentially produced on OD-Cu at potentials presence interface favored nitrite formation low potentials. The originated enhanced adsorption lower barrier potential-determining step (*NH3 → NH3). This work presents an strategy boost electrocatalysis offers insight into real phase corresponding

Language: Английский

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Near-unity electrochemical conversion of nitrate to ammonia on crystalline nickel porphyrin-based covalent organic frameworks

Energy & Environmental Science, Journal Year: 2022, Volume and Issue: 16(1), P. 201 - 209

Published: Nov. 23, 2022

A novel 2D nickel porphyrin-based covalent organic framework is fabricated as an efficient nitrate reduction electrocatalyst that shows a great selectivity of ∼90% under mild overpotential with remarkable production rate and turnover frequency.

Language: Английский

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Unveiling the Reaction Mechanism of Nitrate Reduction to Ammonia Over Cobalt-Based Electrocatalysts

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(19), P. 12976 - 12983

Published: April 3, 2024

Electrocatalytic reduction of nitrate to ammonia (NRA) has emerged as an alternative strategy for sewage treatment and generation. Despite excellent performances having been achieved over cobalt-based electrocatalysts, the reaction mechanism well veritable active species across a wide potential range are still full controversy. Here, we adopt CoP, Co, Co3O4 model materials solve these issues. CoP evolves into core@shell structured CoP@Co before NRA. For Co catalysts, three-step relay is carried out superficial dynamical Coδ+ under low overpotential, while continuous hydrogenation from unveiled high overpotential. In comparison, stable steadily catalyze range. As result, exhibit much higher NRA activity than especially Moreover, performance although they experience same mechanism. A series characterizations clarify reason enhancement highlighting that core donates abundant electrons species, leading generation more hydrogen nitrogen-containing intermediates.

Language: Английский

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