Controllable Electron Distribution Reconstruction of Spinel NiCo₂O₄ Boosting Glycerol Oxidation at Elevated Current Density

Advanced Functional Materials, Год журнала: 2023, Номер 34(3)

Опубликована: Окт. 5, 2023

Abstract Electrocatalytic glycerol oxidation reaction (GOR) is an effective way to convert biomass byproduct high value‐added chemicals, which; however, suffers from the low activity and conversion ratio of presently available catalysts. Herein, NiCo 2 O 4 /NF bimetallic oxide nanoarray controllably fabricated by Ni substituting for octahedral Co 3+ in 3 , which exhibits excellent GOR catalytic at elevated current densities ( E 300 = 1.42 V, 600 1.62 V) overall Faradaic efficiency 97.5% V (FE formic acid 89.9% FE glycolic 7.62%). The performance attributed structure evolution including rapid generation III ‐OOH active species, optimized intermediates adsorption, accelerated electron transfer owing introduction, are evidenced operando spectroscopy measurements density functional theory calculations, respectively. GOR/hydrogen coupled two‐electrode electrolytic cell voltage ≈299 mV lower than that water splitting 50 mA cm −2 . More importantly, compared conventional splitting, this electrolyzer stable over 200 h 1.75 reducing energy consumption 16.9% obtaining products anode concurrently.

Язык: Английский

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Identification of Active Sites Formed on Cobalt Oxyhydroxide in Glucose Electrooxidation

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(15)

Опубликована: Фев. 18, 2023

Transition-metal-based oxyhydroxides are efficient catalysts in biomass electrooxidation towards fossil-fuel-free production of valuable chemicals. However, identification active sites remains elusive. Herein, using cobalt oxyhydroxide (CoOOH) as the archetype and electrocatalyzed glucose oxidation reaction (GOR) model reaction, we track dynamic transformation electronic atomic structure catalyst a suite operando ex situ techniques. We reveal that two types reducible Co3+ -oxo species afforded for GOR, including adsorbed hydroxyl on ion (μ1 -OH-Co3+ ) di-Co3+ -bridged lattice oxygen (μ2 -O-Co3+ ). Moreover, theoretical calculations unveil μ1 is responsible oxygenation, while μ2 mainly contributes to dehydrogenation, both key oxidative steps glucose-to-formate transformation. This work provides framework mechanistic understanding complex near-surface chemistry metal electrorefining.

Язык: Английский

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Optimized Electronic Modification of S-Doped CuO Induced by Oxidative Reconstruction for Coupling Glycerol Electrooxidation with Hydrogen Evolution

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Июль 29, 2023

Abstract Glycerol (electrochemical) oxidation reaction (GOR) producing organic small molecule acid and coupling with hydrogen evolution is a critical aspect of ensuring balanced glycerol capacity promoting generation on large scale. However, the development highly efficient selective non-noble metal-based GOR electrocatalysts still key problem. Here, an S-doped CuO nanorod array catalyst (S-CuO/CF) constructed by sulfur leaching oxidative remodeling used to drive at low potentials: It requires potentials only 1.23 1.33 V versus RHE provide currents 100 500 mA cm −2 , respectively. Moreover, it shows satisfactory comprehensive performance (at cell = 1.37 V) when assembled as anode in asymmetric coupled electrolytic cell. Furthermore, we propose detailed cycle pathway (in alkaline environment) surface produce formic glycolic acid. Among them, C–C bond breaking lattice oxygen deintercalation steps frequently involved are factors determine catalytic product selectivity. This research provides valuable guidance for transition insights into pathway.

Язык: Английский

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Mo−Ni‐based Heterojunction with Fine‐customized d‐Band Centers for Hydrogen Production Coupled with Benzylamine Electrooxidation in Low Alkaline Medium

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(39)

Опубликована: Июнь 14, 2023

Benzylamine electrooxidation reaction (BAOR) is a promising route to produce value-added, easy-separated benzonitrile, and effectively hoist H2 production. However, achieving excellent performance in low alkaline medium huge challenge. The intimately correlated with effective coupling of HER BAOR, which can be achieved by manipulating the d-electron structure catalyst regulate active species from water. Herein, we constructed biphasic Mo0.8 Ni0.2 N-Ni3 N heterojunction for enhanced bifunctional toward coupled BAOR customizing d-band centers. Experimental theoretical calculations indicate that charge transfer causes upshift centers, one side facilitates decrease water activation energy optimize H* adsorption on promoting activity, other favors more easily adsorb OH* forming NiOOH Ni3 optimizing benzylamine, thus catalyzing effectively. Accordingly, it shows an industrial current density 220 mA cm-2 at 1.59 V high Faradaic efficiencies (>99 %) production converting benzylamine benzonitrile 0.1 M KOH/0.5 Na2 SO4 . This work guides design electrocatalysts scalable green hydrogen value-added products.

Язык: Английский

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Unlocking Efficient Hydrogen Production: Nucleophilic Oxidation Reactions Coupled with Water Splitting

Advanced Materials, Год журнала: 2024, Номер unknown

Опубликована: Июнь 10, 2024

Abstract Electrocatalytic water splitting driven by sustainable energy is a clean and promising water‐chemical fuel conversion technology for the production of high‐purity green hydrogen. However, sluggish kinetics anodic oxygen evolution reaction (OER) pose challenges large‐scale hydrogen production, limiting its efficiency safety. Recently, OER has been replaced nucleophilic oxidation (NOR) with biomass as substrate coupled (HER), which attracted great interest. Anode NOR offers faster kinetics, generates high‐value products, reduces consumption. By coupling reaction, can be enhanced while yielding products or degrading pollutants. Therefore, NOR‐coupled HER another new electrolytic strategy after significance realizing development global decarbonization. This review explores potential reactions an alternative to delves into mechanisms, guiding future research in production. It assesses different methods, analyzing pathways catalyst effects. Furthermore, it evaluates role electrolyzers industrialized discusses prospects challenges. comprehensive aims advance efficient economical

Язык: Английский

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Anchored Cobalt Nanoparticles on Layered Perovskites for Rapid Peroxymonosulfate Activation in Antibiotic Degradation

Advanced Materials, Год журнала: 2024, Номер 36(27)

Опубликована: Апрель 16, 2024

Abstract In the Fenton‐like reaction, revealing dynamic evolution of active sites is crucial to achieve activity improvement and stability catalyst. This study reports a perovskite oxide in which atomic (Co 0 ) situ embedded exsolution occurs during high‐temperature phase transition. unique anchoring strategy significantly improves Co 3+ /Co 2+ cycling efficiency at interface inhibits metal leaching peroxymonosulfate (PMS) activation. The Co@L‐PBMC catalyst exhibits superior PMS activation ability could 99% degradation tetracycline within 5 min. combination experimental characterization density functional theory (DFT) calculations elucidates that electron‐deficient oxygen vacancy accepts an electron from 3d‐orbital, resulting significant delocalization site, thereby facilitating adsorption *HSO /*OH intermediate onto “metal‐V O bridge” structure. work provides insights into mechanism level, will guide rational design next‐generation catalysts for environmental remediation.

Язык: Английский

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Strengthening the Synergy between Oxygen Vacancies in Electrocatalysts for Efficient Glycerol Electrooxidation

Advanced Materials, Год журнала: 2024, Номер 36(26)

Опубликована: Апрель 9, 2024

Defect-engineered bimetallic oxides exhibit high potential for the electrolysis of small organic molecules. However, ambiguity in relationship between defect density and electrocatalytic performance makes it challenging to control final products multi-step multi-electron reactions such systems. In this study, controllable kinetics reduction is used maximize oxygen vacancy a Cu─Co oxide nanosheet (CuCo

Язык: Английский

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PtAu alloying-modulated hydroxyl and substrate adsorption for glycerol electrooxidation to C₃ products

Energy & Environmental Science, Год журнала: 2024, Номер 17(12), С. 4205 - 4215

Опубликована: Янв. 1, 2024

A honeycomb-like PtAu alloy catalyst has been developed to modulate the adsorption capacity of OH − species and configuration glycerol on surface for electrocatalytic upgrading C 3 chemicals.

Язык: Английский

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A Solid‐Solution with Asymmetric Ni‐O‐Cr Sites for Boosting Protonation toward Anodic Oxidation

Advanced Energy Materials, Год журнала: 2024, Номер 14(38)

Опубликована: Июль 14, 2024

Abstract Replacing the slow protonation process of oxygen evolution reaction (OER) with fast alcohol electro‐oxidation can decrease driving potentials, thus improving overall efficiency electrochemical devices. However, formation effective catalytic sites for oxidation remains challenging in accelerating to inhibit metal leaching and improve catalyst stability. Herein, asymmetric Ni‐O‐Cr are constructed by alloying Cr into NiO matrix optimize coordination environments, showing significantly enhanced stability during electro‐oxidation. The maintain constant valence states Ni oxidation, efficiently suppressing dissolution even at high potentials. In situ characterizations combined theoretical calculations indicate that adsorption activation OH* molecules compared pure NiO, increasing anodic kinetics. results also smaller gap 3 d ‐O 2 p strengthens charge transfer, leading This work gives insights boosting using sites‐enriched solid‐solution electrocatalysts.

Язык: Английский

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Solar-driven highly selective conversion of glycerol to dihydroxyacetone using surface atom engineered BiVO4 photoanodes

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Июнь 28, 2024

Abstract Dihydroxyacetone is the most desired product in glycerol oxidation reaction because of its highest added value and large market demand among all possible products. However, selectively oxidative secondary hydroxyl groups for highly efficient dihydroxyacetone production still poses a challenge. In this study, we engineer surface BiVO 4 by introducing bismuth-rich domains oxygen vacancies (Bi-rich 4-x ) to systematically modulate adsorption enhance photo-induced charge separation photoelectrochemical into conversion. As result, Bi-rich increases photocurrent density from 1.42 4.26 mA cm −2 at 1.23 V vs. reversible hydrogen electrode under AM 1.5 G illumination, as well selectivity 54.0% 80.3%, finally achieving rate 361.9 mmol m h −1 that outperforms reported values. The atom customization opens way regulate solar-driven organic transformation pathway toward carbon chain-balanced product.

Язык: Английский

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