Ion solvation kinetics in bipolar membranes and at electrolyte–metal interfaces

Nature Energy, Год журнала: 2024, Номер 9(5), С. 548 - 558

Опубликована: Март 14, 2024

Abstract Ion (de)solvation at solid–electrolyte interfaces is pivotal for energy and chemical conversion technology, such as (electro)catalysis, batteries bipolar membranes. For example, during the electrocatalytic hydrogen evolution reaction in alkaline media, water needs to be dissociated hydroxide ions solvated—a process that not well understood. Here we study dissociation ion solvation kinetics isolation polymeric membrane electrolyte–metal interfaces. We discover bias-dependent relationships between activation entropy enthalpy, which link a dispersion of interfacial capacitance. Furthermore, our results indicate OH − kinetically slower than H + display characteristics are independent catalyst structure. attribute this universal amount excess charge needed induce electric fields alter water. Of fundamental interest, these critical enable knowledge-driven electrocatalyst design.

Язык: Английский

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Highly Selective Electrochemical Baeyer–Villiger Oxidation through Oxygen Atom Transfer from Water

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(19), С. 13438 - 13444

Опубликована: Апрель 30, 2024

The Baeyer–Villiger oxidation of ketones is a crucial oxygen atom transfer (OAT) process used for ester production. Traditionally, accomplished by thermally oxidizing the OAT from stoichiometric peroxides, which are often difficult to handle. Electrochemical methods hold promise breaking limitation using water as source. Nevertheless, existing demonstrations electrochemical face challenges low selectivity. We report in this study strategy overcome challenge. By employing well-known catalyst, Fe2O3, we achieved nearly perfect selectivity cyclohexanone. Mechanistic studies suggest that it essential produce surface hydroperoxo intermediates (M-OOH, where M represents metal center) promote nucleophilic attack on ketone substrates. confining reactions catalyst surfaces, competing (e.g., dehydrogenation, carboxylic acid cation rearrangements, and hydroxylation) greatly limited, thereby offering high surface-initiated nature reaction confirmed kinetic spectroelectrochemical characterizations. This discovery adds toolbox organic synthesis.

Язык: Английский

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Ultrafast Interfacial Self‐Assembly toward Bioderived Polyester COF Membranes with Microstructure Optimization

Advanced Materials, Год журнала: 2024, Номер 36(32)

Опубликована: Июнь 11, 2024

Abstract The precise manipulation of the microstructure (pore size, free volume distribution, and connectivity free‐volume elements), thickness, mechanical characteristics membranes holds paramount significance in facilitating effective utilization self‐standing membranes. In this contribution, synthesis two innovative ester‐linked covalent–organic framework (COF) is first reported, which are generated through selection plant‐derived ellagic acid quercetin phenolic monomers conjunction with terephthaloyl chloride as a building block. optimization these COF systematically achieved application three different interfacial electric field systems: neutrality, positive electricity, negative electricity. It observed that positively charged system facilitates record increase rate membrane formation, resulting denser uniform pore size enhanced flexibility. addition, correlation identified wherein an alkyl chain length surfactants leads to more decrease molecular weight cutoff membrane. exhibits unprecedented combination high water permeance, superior sieving capability, robust strength, chemical robustness for promising membrane‐based separation science technology.

Язык: Английский

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Durable and Active Fe–N–C Assisted by Fe Nanoparticle and Graphitic Layers for Efficient Carbamate Decomposition During Amine‐Based Carbon Capture

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Фев. 10, 2025

Abstract A feasible Fe–N–C catalysts (Fe/Fe SA @GNC) with multiple Fe species and well‐graphitized carbon layers is prepared to boost the carbamate decomposition kinetics for energy‐saving CO 2 capture amine solvent. precursor carbothermic reaction creates graphitic doped pyridinic‐N, which significantly enhances activity of coordinated sites. Furthermore, enclosed nanoparticles originate from excess firmed atomically dispersed sites in layers. The as‐prepared exhibit superior under relatively mild conditions. maximum desorption rate soar 5.4 mmol min −1 , marking 440% increment compared catalyst‐free reaction. Notably, Fe/Fe @GNC delivered exceptional stability durability after 20 cycles alkaline organic solutions, single‐atom without NPs. Bench‐scale testing continuous absorption presented a 19.5% increase efficiency 40.7% decrease heat duty only 0.1 wt.% dosage @GNC. role demonstrated process proton transfer C−N breaking during solvent regeneration (CO desorption). Thus, catalytic offered an appealing technology solution high challenge associated chemisorption using amine‐based

Язык: Английский

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Wireless potentiometry of thermochemical heterogeneous catalysis

Nature Catalysis, Год журнала: 2025, Номер unknown

Опубликована: Апрель 2, 2025

Язык: Английский

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Activating TiO₂ through the Phase Transition‐Mediated Hydrogen Spillover to Outperform Pt for Electrocatalytic pH‐Universal Hydrogen Evolution

Small, Год журнала: 2024, Номер unknown

Опубликована: Апрель 4, 2024

Abstract Endowing conventional materials with specific functions that are hardly available is invariably of significant importance but greatly challenging. TiO 2 proven to be highly active for the photocatalytic hydrogen evolution while intrinsically inert electrocatalytic reaction (HER) due its poor electrical conductivity and unfavorable adsorption/desorption behavior. Herein, first activation HER demonstrated by synergistically modulating positions d‐band center triggering spillover through dual doping‐induced partial phase transition. The N, F co‐doping‐induced transition from anatase rutile in (AR‐TiO |(N,F)) exhibits extraordinary performance overpotentials 74, 80, 142 mV at a current density 10 mA cm –2 1.0 M KOH, 0.5 H SO 4 , phosphate‐buffered saline electrolytes, respectively, which substantially better than pure even superior benchmark Pt/C catalysts. These findings may open new avenue development low‐cost alternative noble metal catalysts production.

Язык: Английский

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Bias Dependence of the Transition State of the Hydrogen Evolution Reaction

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Фев. 3, 2025

The hydrogen evolution reaction (HER) is one of the most prominent electrocatalytic reactions green energy transition. However, kinetics across materials and electrolyte pH impact coverage at high current densities remain poorly understood. Here, we study HER over a large set nanoparticle catalysts in industrially relevant acidic alkaline membrane electrode assemblies that are only operated with pure water humidified gases. We discover distinct kinetic fingerprints between iron triad (Fe, Ni, Co), coinage (Au, Cu, Ag), platinum group metals (Ir, Pt, Pd, Rh). Importantly, applied bias changes not activation (EA) but also pre-exponential factor (A). interpret these as entropic interfacial solvent differ acid base on surface due to changing coverage. Finally, observe anions can induce Butler–Volmer behavior for acid. Our results provide new foundation understand and, more broadly, highlight pressing need update common understanding basic concepts field electrocatalysis.

Язык: Английский

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Non-Nernstian Effects in Theoretical Electrocatalysis

Chemical Reviews, Год журнала: 2025, Номер unknown

Опубликована: Март 6, 2025

Electrocatalysis is one of the principal pathways for transition to sustainable chemistry, promising greater energy efficiency and reduced emissions. As field has grown, our theoretical understanding matured. The influence applied potential on reactivity developed from first-order predictions based Nernst equation implicit inclusion second-order effects including interaction reacting species with interfacial electric field. In this review, we explore these non-Nernstian in electrocatalysis, aiming both understand exploit them through theory computation. We summarize critical distinction between Nernstian outline strategies address latter studies. Subsequently, examine specific energetic contributions capacitive faradaic processes separately. also underscore importance considering catalyst screening mechanistic analysis. Finally, provide suggestions how experimentally unravel effects, offering insights into practical approaches advancing

Язык: Английский

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Exploring the Linear Energy Relationships between Activation Energy and Reaction Energy under an Electric Field

Journal of Chemical Theory and Computation, Год журнала: 2025, Номер unknown

Опубликована: Апрель 17, 2025

Electric-field (EF)-mediated chemistry has recently garnered increasing attention partly owing to its capability catalyze a broad range of chemical reactions. How the EF affects kinetics and thermodynamics target reactions is critical question. Herein, both density functional theory (DFT) MP2 calculations suggest that change activation energy ΔΔE‡ reaction ΔΔErxn under an display linear relationship (LER) = mΔΔErxn. This been tested against several such as SN2 proton transfer reactions, including neutral charged systems endothermic exothermic processes. The coefficient m approximates ratio dipole moment change, i.e., Δμ‡/Δμrxn, studied LER holds well at strengths up ≈1 V/nm but deviates from DFT-calculated results larger EFs. Such deviations are mainly caused by molecular geometry changes EF. Systems with polarizability experience greater EF, thus leading deviations. In addition, we propose barrier can be predicted -Δμ‡F - 0.5Δα‡F2, while it approximated for small strengths. proposed field-dependent estimation promise applicability in EF-mediated

Язык: Английский

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Proton-coupled electron transfer controls peroxide activation initiated by a solid-water interface

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Апрель 22, 2025

Decentralized water treatment technologies, designed to align with the specific characteristics of source and requirements user, are gaining prominence due their cost energy-saving advantages over traditional centralized systems. The application chemical via heterogeneous advanced oxidation processes using peroxide (O-O) represents a potentially attractive option. These serve initiate redox at solid-water interface. Nevertheless, mechanism exemplified by typical Fenton-like persulfate-based oxidation, in which electron transfer dominates, is almost universally accepted. Here, we present experimental results that challenge this view. At solid-liquid interface, it demonstrated protons thermodynamically coupled electrons. In situ quantitative titration provides direct evidence coupling ratio transferred electrons 1:1. Comprehensive thermodynamic analyses further demonstrate net proton-coupled occurs, both entering cycle. findings will inform future developments O-O activation enabling more efficient activity tight

Язык: Английский

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