Electrolyte Effects on CO₂ Electrochemical Reduction to CO

Accounts of Chemical Research, Год журнала: 2022, Номер 55(14), С. 1900 - 1911

Опубликована: Июнь 30, 2022

ConspectusThe electrochemical reduction of CO2 (CO2RR) constitutes an alternative to fossil fuel-based technologies for the production fuels and commodity chemicals. Yet application CO2RR electrolyzers is hampered by low energy Faradaic efficiencies. Concomitant reactions, like hydrogen evolution (HER), lower selectivity, while conversion into (bi)carbonate through solution acid-base reactions induces additional concentration overpotential. During in aqueous media, local pH becomes more alkaline than bulk causing consumption homogeneous reactions. The latter effect, combination with solubility electrolytes (33 mM), leads a significant depletion at electrode surface.The nature electrolyte, terms cation identity, has recently emerged as important factor tune both efficiency. In this Account, we summarize recent advances understanding electrolyte effects on CO solutions, which first, crucial, step further reduced products. To compare literature findings meaningful way, focus results reported under well-defined mass transport conditions using online analytical techniques. discussion covers molecular-level proton donor, suppression gradient vs enhancement HER given rate cation, crucial enabling HER. These mechanistic insights are then translated possible implications industrially relevant cell geometries current densities.

Язык: Английский

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Water electrolysis

Nature Reviews Methods Primers, Год журнала: 2022, Номер 2(1)

Опубликована: Окт. 27, 2022

Язык: Английский

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Electrochemical reduction of carbon dioxide to multicarbon (C₂₊) products: challenges and perspectives

Energy & Environmental Science, Год журнала: 2023, Номер 16(11), С. 4714 - 4758

Опубликована: Янв. 1, 2023

This review analyzes advanced catalysts and C 2+ synthesis mechanisms based on theoretical explorations in situ / operando characterizations. Triphasic interface optimization is discussed for the potential of industry-compatible stability.

Язык: Английский

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CO2 electroreduction to multicarbon products in strongly acidic electrolyte via synergistically modulating the local microenvironment

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Дек. 9, 2022

Electrochemical CO2 reduction to multicarbon products faces challenges of unsatisfactory selectivity, productivity, and long-term stability. Herein, we demonstrate electroreduction in strongly acidic electrolyte (pH ≤ 1) on electrochemically reduced porous Cu nanosheets by combining the confinement effect cation synergistically modulate local microenvironment. A Faradaic efficiency 83.7 ± 1.4% partial current density 0.56 0.02 cm-2, single-pass carbon 54.4%, stable electrolysis 30 h a flow cell are demonstrated for aqueous consisting sulfuric acid KCl with pH 1. Mechanistically, accumulated species (e.g., K+ OH-) Helmholtz plane account selectivity activity toward kinetically reducing proton coverage thermodynamically favoring conversion. We find that cations facilitate C-C coupling through interaction between key intermediate *OCCO.

Язык: Английский

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Cationic-group-functionalized electrocatalysts enable stable acidic CO2 electrolysis

Nature Catalysis, Год журнала: 2023, Номер 6(9), С. 763 - 772

Опубликована: Авг. 21, 2023

Язык: Английский

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Close to 90% Single-Pass Conversion Efficiency for CO₂ Electroreduction in an Acid-Fed Membrane Electrode Assembly

ACS Energy Letters, Год журнала: 2022, Номер 7(12), С. 4224 - 4231

Опубликована: Окт. 31, 2022

The formation of (bi)carbonates is a pressing issue for CO2 electroreduction in neutral or alkaline solutions. It adversely causes low single-pass conversion efficiency as result (bi)carbonate crossover, well limited device lifetimes precipitation at the cathode. One emerging solution to circumvent this challenge conducting reaction acids. To end, we here demonstrate an acid-fed membrane electrode assembly (MEA) CO. A diluted electrolyte with H+ Cs+ ratio 1:1 and relatively current density are optimal conditions achieve high CO Faradaic efficiencies. versus offers electrocatalytic activities. By systematically evaluating impact concentration on electrochemical performance, uncover essential role balance between rates diffusion determining selectivity activity. As result, report partial ∼105 mA cm–2 ∼4 V cell voltage, near-doubled activity toward compared MEA similar voltage. Under long-term operation, our capable delivering ∼80%, extraordinary ∼90% (about twice that MEA), 50 h stability notably superior those previous reports.

Язык: Английский

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A unifying mechanism for cation effect modulating C1 and C2 productions from CO2 electroreduction

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Сен. 19, 2022

Abstract Electrocatalysis, whose reaction venue locates at the catalyst–electrolyte interface, is controlled by electron transfer across electric double layer, envisaging a mechanistic link between rate and layer structure. A fine example in CO 2 reduction reaction, of which shows strong dependence on alkali metal cation (M + ) identity, but there yet to be unified molecular picture for that. Using quantum-mechanics-based atom-scale simulation, we herein scrutinize M -coupling capability possible intermediates, establish H - -associated ET mechanisms CH 4 CO/C formations, respectively. These theoretical scenarios are successfully underpinned Nernstian shifts polarization curves with or concentrations first-order kinetics formation electrode surface charge density. Our finding further rationalizes merit using Nafion-coated enhanced C2 production terms

Язык: Английский

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Engineering the NiNC Catalyst Microenvironment Enabling CO₂ Electroreduction with Nearly 100% CO Selectivity in Acid

Advanced Materials, Год журнала: 2022, Номер 34(38)

Опубликована: Июль 28, 2022

CO2 electrolysis in acid has emerged as a promising route to achieve high utilization due the inhibition of undesired carbonate formation that generally occurs alkaline or neutral conditions. However, efficiency and stability this system need be further improved through tailoring electrocatalyst its working environment. Here, microenvironment structurally engineered NiNC catalyst for acidic is probed optimized by adding hydrophobic poly(tetrafluoroethylene) (PTFE) nanoparticles catalytic layer gas-diffusion electrodes. The PTFE-modified electrode delivers nearly 100% CO Faradaic at an industry-relevant current density 250 mA cm-2 , single-pass 75.7% 200 under 20 sccm gas flow rate. Moreover, compared conventional without added PTFE, exhibits substantially enhanced water-flooding-resistant ability. Mechanistic investigations reveal moderate PTFE modification can optimize local /H2 O ratio layer, favoring reduction diffusion thickness highly active stable solid-liquid-gas interfacial microenvironment.

Язык: Английский

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A Porous π–π Stacking Framework with Dicopper(I) Sites and Adjacent Proton Relays for Electroreduction of CO₂ to C₂₊ Products

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(29), С. 13319 - 13326

Опубликована: Июль 1, 2022

Crystalline porous materials sustained by supramolecular interactions (e.g., π–π stacking interactions) are a type of molecular crystals showing considerable stability, but their applications rarely reported due to the high difficulty construction. Herein, stable framework formed trinuclear copper(I) compound [Cu3(HBtz)3(Btz)Cl2] (CuBtz, HBtz = benzotriazole) with pyrazolate-bridged dicopper(I) sites is and employed for electrochemical CO2 reduction, an impressive performance 73.7 ± 2.8% Faradaic efficiency C2+ products [i.e., ethylene (44%), ethanol (21%), acetate (4.7%), propanol (4%)] current density 7.9 mA cm–2 at potential −1.3 V versus RHE in H-type cell Faradic (61.6%) ≈1 A reaction rate 5639 μmol m–2 s–1 −1.6 flow device, representing date. In-situ infrared spectroscopy, functional theory calculations, control experiments revealed that uncoordinated nitrogen atoms benzotriazolates immediate vicinity can act as proton relays cooperate site promote hydrogenation process *CO intermediate C–C coupling, resulting highly selective electroreduction products.

Язык: Английский

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Understanding and leveraging the effect of cations in the electrical double layer for electrochemical CO2 reduction

Chem Catalysis, Год журнала: 2022, Номер 2(6), С. 1267 - 1276

Опубликована: Апрель 18, 2022

Язык: Английский

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