Atomically dispersed materials: Ideal catalysts in atomic era

Nano Research, Journal Year: 2023, Volume and Issue: 17(1), P. 18 - 38

Published: May 25, 2023

Language: Английский

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

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Sept. 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

Language: Английский

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Understanding Cation Effects on the Hydrogen Evolution Reaction

ACS Energy Letters, Journal Year: 2022, Volume and Issue: 8(1), P. 657 - 665

Published: Dec. 21, 2022

The hydrogen evolution reaction (HER) is known to be influenced by the identity of alkali metal cations in electrolyte. But a clear understanding this behavior has not been developed. Here, we present results experimental and theoretical studies that describe how influence HER acidic basic electrolytes. Alkali are shown have no systematic effect on rates acid. In alkaline media, decrease with increasing cation size over Ir, Pd, Pt (Li+ > Na+ K+ Cs+) increase Cu, Ag, Au < Cs+). We argue interfacial lower activation barrier for water dissociation, an elementary step unique media. limited but Pt, explaining inverted activity trend. Based ab initio molecular dynamics simulations, suggest trends attributable greater willingness large, weakly solvated approach electrode surface.

Language: Английский

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Metal–Organic Framework Supercapacitors: Challenges and Opportunities

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 34(43)

Published: Sept. 17, 2023

Abstract Supercapacitors offer superior energy storage capabilities than traditional capacitors, making them useful for applications such as electric vehicles and rapid large‐scale storage. The performance of these devices relies on electrical double‐layer capacitance and/or pseudocapacitance from reversible redox reactions. Metal–organic frameworks (MOFs) have recently emerged a new class electrode materials with promising supercapacitor performances capacitances that exceed those materials. However, the comparison porous carbon state‐of‐the‐art MOF highlights number challenges supercapacitors, including low potential windows, limited cycle lifetimes, poor rate performances. It is proposed well‐defined tuneable chemical structures MOFs present avenues improving performance. Recent experimental theoretical work charging mechanisms in MOF‐based supercapacitors also discussed, it found there need more studies elucidate charge degradation mechanisms. Ultimately, deeper understanding will lead to design principles realizing improved devices.

Language: Английский

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Surface-immobilized cross-linked cationic polyelectrolyte enables CO2 reduction with metal cation-free acidic electrolyte

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Sept. 13, 2023

Electrochemical CO2 reduction in acidic electrolytes is a promising strategy to achieve high utilization efficiency of CO2. Although alkali cations play vital role suppressing hydrogen evolution and promoting reduction, they also cause precipitation bicarbonate on the gas diffusion electrode (GDE), flooding electrolyte through GDE, drift pH. In this work, we realize electroreduction metal cation-free by covering catalyst with cross-linked poly-diallyldimethylammonium chloride. This polyelectrolyte provides density cationic sites immobilized surface catalyst, which suppresses mass transport H+ modulates interfacial field strength. By adopting strategy, Faradaic (FE) CO reaches 95 ± 3% Ag FE formic acid 76 1.0 pH flow cell. More importantly, amount GDE decreased 2.5 0.6% that cation-containing electrolyte, maintains above 80% over 36 h operation at -200 mA·cm-2.

Language: Английский

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Cation-Coordinated Inner-Sphere CO₂ Electroreduction at Au–Water Interfaces

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(3), P. 1897 - 1905

Published: Jan. 11, 2023

Electrochemical CO2 reduction reaction (CO2RR) is a promising technology for the clean energy economy. Numerous efforts have been devoted to enhancing mechanistic understanding of CO2RR from both experimental and theoretical studies. Electrolyte ions are critical CO2RR; however, role alkali metal cations highly controversial, complete free diagram at Au–water interfaces still missing. Here, we provide systematic mechanism study toward via ab initio molecular dynamics simulations integrated with slow-growth sampling (SG-AIMD) method. By using SG-AIMD approach, demonstrate that facile inner-sphere interface in presence K cations, which promote activation barrier only 0.66 eV. Furthermore, competitive hydrogen evolution (HER) inhibited by interfacial induced kinetic blockage effect, where rate-limiting Volmer step shows much higher (1.27 eV). Eventually, comprehensive including kinetics thermodynamics CO HER electrochemical derived, illustrates on overall performance electroreduction facilitating adsorption while suppressing same time.

Language: Английский

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Promoting Cu-catalysed CO2 electroreduction to multicarbon products by tuning the activity of H2O

Nature Catalysis, Journal Year: 2023, Volume and Issue: 6(9), P. 807 - 817

Published: Aug. 31, 2023

Language: Английский

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Cation-induced changes in the inner- and outer-sphere mechanisms of electrocatalytic CO2 reduction

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Nov. 22, 2023

The underlying mechanism of cation effects on CO2RR remains debated. Herein, we study by simulating both outer-sphere electron transfer (OS-ET) and inner-sphere (IS-ET) pathways during via constrained density functional theory molecular dynamics (cDFT-MD) slow-growth DFT-MD (SG-DFT-MD), respectively. Our results show without any cations, only OS-ET is feasible with a barrier 1.21 eV. In the presence K+ (Li+), shows very high 2.93 eV (4.15 eV) thus being prohibited. However, cations promote CO2 activation through IS-ET 0.61 (K+) 0.91 generating key intermediate (adsorbed CO[Formula: see text]). Without CO2-to-CO[Formula: text](ads) conversion cannot proceed. findings reveal arise from short-range Coulomb interactions reaction intermediates. These disclose that modulate inner- CO2RR, offering substantial insights specificity in initial steps.

Language: Английский

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The importance of a charge transfer descriptor for screening potential CO2 reduction electrocatalysts

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: May 5, 2023

Abstract It has been over twenty years since the linear scaling of reaction intermediate adsorption energies started to coin fields heterogeneous and electrocatalysis as a blessing curse at same time. established possibility construct activity volcano plots function single or two readily accessible descriptors, but also limited maximal catalytic conversion rate. In this work, it is found that these energy-based descriptor spaces are not applicable electrochemistry, because they lacking an important additional dimension, potential zero charge. This extra dimension arises from interaction electric double layer with intermediates which does scale energies. At example electrochemical reduction CO 2 shown addition breaks relations, opening up huge chemical space via charge-based material design. The charge explains product selectivity trends in close agreement reported experimental data highlighting its importance for electrocatalyst

Language: Английский

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Molecular understanding of the critical role of alkali metal cations in initiating CO2 electroreduction on Cu(100) surface

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Jan. 19, 2024

Abstract Molecular understanding of the solid–liquid interface is challenging but essential to elucidate role environment on kinetics electrochemical reactions. Alkali metal cations (M + ), as a vital component at interface, are found be necessary for initiation carbon dioxide reduction reaction (CO 2 RR) coinage metals, and activity selectivity CO RR could further enhanced with cation changing from Li Cs , while underlying mechanisms not well understood. Herein, using ab initio molecular dynamics simulations explicit solvation sampling methods, we systematically investigate M in Cu surface. A monotonically decreasing activation barrier obtained which attributed different coordination abilities *CO . Furthermore, show that competing hydrogen evolution must considered simultaneously understand crucial alkali surfaces, where H repelled constrained by Our results provide significant insights into design environments highlight importance explicitly including reactions theoretical RR.

Language: Английский

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