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

ACS Energy Letters, Journal Year: 2022, Volume and Issue: 7(12), P. 4224 - 4231

Published: Oct. 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.

Language: Английский

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Membrane Electrode Assembly for Electrocatalytic CO₂ Reduction: Principle and Application

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(28)

Published: March 27, 2023

Abstract Electrocatalytic CO 2 reduction reaction (CO RR) in membrane electrode assembly (MEA) systems is a promising technology. Gaseous can be directly transported to the cathode catalyst layer, leading enhanced rate. Meanwhile, there no liquid electrolyte between and anode, which help improve energy efficiency of whole system. The remarkable progress achieved recently points out way realize industrially relevant performance. In this review, we focus on principles MEA for RR, focusing gas diffusion electrodes ion exchange membranes. Furthermore, anode processes beyond oxidation water are considered. Besides, voltage distribution scrutinized identify specific losses related individual components. We also summarize generation different reduced products together with corresponding catalysts. Finally, challenges opportunities highlighted future research.

Language: Английский

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Conjugated Coordination Polymer as a New Platform for Efficient and Selective Electroreduction of Nitrate into Ammonia

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(10)

Published: Jan. 18, 2023

Electroreduction of nitrate into ammonia (NRA) provides a sustainable route to convert the widespread pollutants high-value-added products under ambient conditions, which unfortunately suffers from unsatisfactory selectivity due competitive hydrogen evolution reaction (HER). Previous strategies modifying metal sites catalysts often met dilemma for simultaneously promoting activity and toward NRA. Here, general strategy is reported enable an efficient selective NRA process through coordination modulation single-atom tailor local proton concentration at catalyst surface. By contrast, two analogous Ni-single-atom enriched conjugated polymers (NiO4 -CCP NiN4 -CCP) with different motifs are investigated proof-of-concept study. The NiO4 exhibits yield rate as high 1.83 mmol h-1 mg-1 Faradaic efficiency 94.7% current density 125 mA cm-2 , outperforming catalyst. These experimental theoretical studies both suggest that can not only accelerate by adjusting adsorption energies intermediates on but also inhibit HER regulating migration contributions metal-hydrated cations adsorbed surface, thus achieving simultaneous enhancement activity.

Language: Английский

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Boosting Hydrogen Peroxide Electrosynthesis via Modulating the Interfacial Hydrogen‐Bond Environment

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(27)

Published: May 10, 2023

Abstract Designing highly efficient and stable electrode‐electrolyte interface for hydrogen peroxide (H 2 O ) electrosynthesis remains challenging. Inhibiting the competitive side reaction, 4 e − oxygen reduction to H O, is essential selective electrosynthesis. Instead of hindering excessive hydrogenation via catalyst modification, we discover that adding a hydrogen‐bond acceptor, dimethyl sulfoxide (DMSO), KOH electrolyte enables simultaneous improvement selectivity activity Spectral characterization molecular simulation confirm formation bonds between DMSO water molecules at can reduce dissociation into active H* species. The suitable supply environment hinders reaction (ORR), thus improving ORR achieving over 90 % . This work highlights importance regulating interfacial by organic as means boosting electrochemical performance in aqueous beyond.

Language: Английский

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Electrochemical Carbon Dioxide Reduction to Ethylene: From Mechanistic Understanding to Catalyst Surface Engineering

Nano-Micro Letters, Journal Year: 2023, Volume and Issue: 15(1)

Published: July 11, 2023

Electrochemical carbon dioxide reduction reaction (CO2RR) provides a promising way to convert CO2 chemicals. The multicarbon (C2+) products, especially ethylene, are of great interest due their versatile industrial applications. However, selectively reducing ethylene is still challenging as the additional energy required for C-C coupling step results in large overpotential and many competing products. Nonetheless, mechanistic understanding key steps preferred pathways/conditions, well rational design novel catalysts production have been regarded approaches achieving highly efficient selective CO2RR. In this review, we first illustrate CO2RR (e.g., adsorption/activation, formation *CO intermediate, step), offering conversion ethylene. Then alternative pathways conditions competitive products (C1 other C2+ products) investigated, guiding further development generation. Engineering strategies Cu-based CO2RR-ethylene summarized, correlations mechanism/pathways, engineering selectivity elaborated. Finally, major challenges perspectives research area proposed future practical

Language: Английский

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Electrochemical CO2 reduction catalyzed by organic/inorganic hybrids

eScience, Journal Year: 2023, Volume and Issue: 3(2), P. 100097 - 100097

Published: Jan. 18, 2023

Electroreduction of CO2 into value-added chemicals and fuels utilizing renewable electricity offers a sustainable way to meet the carbon-neutral goal viable solution for storage intermittent green energy sources. At core this technology is development electrocatalysts accelerate redox kinetics reduction reactions (CO2RR) toward high targeted-product yield at minimal input. This perspective focuses on unique category CO2RR embodying both inorganic organic components synergistically promote reaction activity, selectivity stability. First, we summarize recent progress design fabrication organic/inorganic hybrids electrocatalysts, with special attention assembly protocols structural configurations. We then carry out comprehensive discussion mechanistic understanding processes tackled jointly by phases, respect regulation mass charge transport, modification double-layer configuration, tailoring intermediates adsorption, establishment tandem pathways. end, outline future challenges in rational further extend scope device level. hope work could incentivize more research interests construct mobilizing electrocatalytic towards industrialization.

Language: Английский

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Tuning the Interfacial Reaction Environment for CO₂ Electroreduction to CO in Mildly Acidic Media

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(8), P. 5242 - 5251

Published: Feb. 13, 2024

A considerable carbon loss of CO2 electroreduction in neutral and alkaline media severely limits its industrial viability as a result the homogeneous reaction OH– under interfacial alkalinity. Here, to mitigate reactions, we conducted mildly acidic media. By modulating environment via multiple electrolyte effects, parasitic hydrogen evolution is suppressed, leading faradaic efficiency over 80% for CO on planar Au electrode. Using rotating ring-disk electrode technique, ring constitutes an situ collector pH sensor, enabling recording Faradaic monitoring while reduction takes place disk. The dominant branch switches from proton water changes alkaline. comparison, starts within region approaches near-neutral conditions. Thereafter, decays, place, protons are increasingly consumed by electrogenerated reduction. reaches maximum just before initiates. Slowing mass transport lowers current, hardly influenced. In contrast, appropriate protic anion, e.g., HSO4– our case, weakly hydrated cations, K+, accelerate reduction, with former providing extra flux but higher local pH, latter stabilizing *CO2– intermediate.

Language: Английский

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Electrochemical nitrate reduction to ammonia with cation shuttling in a solid electrolyte reactor

Nature Catalysis, Journal Year: 2024, Volume and Issue: 7(9), P. 1032 - 1043

Published: Aug. 12, 2024

Language: Английский

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Modulating the Electrolyte Microenvironment in Electrical Double Layer for Boosting Electrocatalytic Nitrate Reduction to Ammonia

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(32)

Published: May 29, 2024

Abstract Electrochemical nitrate reduction reaction (NO 3 RR) is a promising approach to achieve remediation of nitrate‐polluted wastewater and sustainable production ammonia. However, it still restricted by the low activity, selectivity Faraday efficiency for ammonia synthesis. Herein, we propose an effective strategy modulate electrolyte microenvironment in electrical double layer (EDL) mediating alkali metal cations enhance NO RR performance. Taking bulk Cu as model catalyst, experimental study reveals that − ‐to‐NH performance different electrolytes follows trend Li + <Cs <Na <K . Theoretical studies illustrate proton transport rate activity rate‐determining step 2 ) increase order The cation effects are also general two typical nanostructured catalysts including copper/cuprous oxide nickel phosphides, achieving near‐100 % Faradaic over 99 conversion NH Furthermore, demonstrate can be converted high‐purity 4 Cl catalyst K ‐containing electrolyte.

Language: Английский

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Immobilized Tetraalkylammonium Cations Enable Metal‐free CO₂ Electroreduction in Acid and Pure Water

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(9)

Published: Jan. 2, 2024

Abstract Carbon dioxide reduction reaction (CO 2 RR) provides an efficient pathway to convert CO into desirable products, yet its commercialization is greatly hindered by the huge energy cost due loss and regeneration. Performing RR under acidic conditions containing alkali cations can potentially address issue, but still causes (bi)carbonate deposition at high current densities, compromising product Faradaic efficiencies (FEs) in present‐day acid‐fed membrane electrode assemblies. Herein, we present a strategy using positively charged polyelectrolyte—poly(diallyldimethylammonium) immobilized on graphene oxide via electrostatic interactions displace cations. This enables FE of 85 %, carbon efficiency 93 (EE) 35 % for 100 mA cm −2 modified Ag catalysts acid. In pure‐water‐fed reactor, obtained 78 with 30 EE 40 °C. All performance metrics are comparable or even exceed those attained presence metal

Language: Английский

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