Tafel Slope Plot as a Tool to Analyze Electrocatalytic Reactions

ACS Energy Letters, Journal Year: 2024, Volume and Issue: 9(4), P. 1871 - 1879

Published: April 1, 2024

Kinetic and nonkinetic contributions to the Tafel slope value can be separated using a plot, where constant region indicates kinetic meaningfulness. Here, we compare values obtained from linear sweep voltammetry chronoamperometry impedance spectroscopy, apply plot various electrocatalytic reactions. We show that similar are observed different techniques under high-mass-transport conditions for oxygen evolution reaction on NiFeOOH in 0.2 M KOH. However, alkaline hydrogen CO2 reduction reaction, no horizontal regions were observed. In contrast, expected of 30 mV/dec HER Pt 1 HClO4. argue widespread application or numerical differentiation techniques, would result an improved comparison data many reactions when traditional analysis is ambiguous.

Language: Английский

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Local reaction environment in electrocatalysis

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(4), P. 2022 - 2055

Published: Jan. 1, 2024

Beyond conventional electrocatalyst engineering, recent studies have unveiled the effectiveness of manipulating local reaction environment in enhancing performance electrocatalytic reactions. The general principles and strategies environmental engineering for different processes been extensively investigated. This review provides a critical appraisal advancements aiming to comprehensively assess this emerging field. It presents interactions among surface structure, ions distribution electric field relation environment. Useful protocols such as interfacial reactant concentration, mass transport rate, adsorption/desorption behaviors, binding energy are in-depth discussed toward modifying Meanwhile, electrode physical structures cell configurations viable optimization methods environments. In combination with

Language: Английский

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Confined Water for Catalysis: Thermodynamic Properties and Reaction Kinetics

Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 4, 2025

Water is a salient component in catalytic systems and acts as reactant, product and/or spectator species the reaction. Confined water distinct local environments can display significantly different behaviors from that of bulk water. Therefore, wide-ranging chemistry confined provide tremendous opportunities to tune reaction kinetics. In this review, we focus on drawing connection between properties kinetics for heterogeneous (electro)catalysis. First, are presented, where enthalpy, entropy, dielectric be regulated by tuning geometry hydrophobicity cavities. Second, experimental computational studies investigate interactions inorganic materials, such carbon nanotubes (1D confinement), charged metal or oxide surfaces (2D), zeolites metal–organic frameworks (3D) ions/solvent molecules (0D), reviewed demonstrate opportunity create structures with unique H-bonding network properties. Third, role structure dynamics governing activation free energy, reorganization energy pre-exponential factor (electro)catalysis discussed. We highlight emerging enhance proton-coupled electron transfer optimizing interfacial H-bond networks regulate decarbonization chemicals fuels.

Language: Английский

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Cation effect on the elementary steps of the electrochemical CO reduction reaction on Cu

Nature Catalysis, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 23, 2024

Language: Английский

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Cation effects in hydrogen evolution and CO2-to-CO conversion: A critical perspective

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 160(16)

Published: April 23, 2024

The rates of many electrocatalytic reactions can be strongly affected by the structure and dynamics electrochemical double layer, which in turn tuned concentration identity supporting electrolyte's cation. effect cations on an process depends a complex interplay between electrolyte components, electrode material surface structure, applied potential, reaction intermediates. Although cation effects remain insufficiently understood, principal mechanisms underlying cation-dependent reactivity selectivity are beginning to emerge. In this Perspective, we summarize critically examine recent advances area context hydrogen evolution (HER) CO2-to-CO conversion, among most intensively studied promising for sustainable production commodity chemicals fuels. Improving kinetics HER base enabling energetically efficient selective CO2 reduction at low pH key challenges electrocatalysis. physical insights from literature illustrate how utilized help achieve these goals steer other processes technological relevance.

Language: Английский

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Disentangling Multiple pH-Dependent Factors on the Hydrogen Evolution Reaction at Au(111)

Precision Chemistry, Journal Year: 2025, Volume and Issue: 3(3), P. 135 - 148

Published: Jan. 8, 2025

Understanding how the electrolyte pH affects electrocatalytic activity is a topic of crucial importance in large variety systems. However, unraveling origin effects complicated often by fact that both reaction driving forces and reactant concentrations electric double layer (EDL) change simultaneously with value. Herein, we employ hydrogen evolution (HER) at Au(111)-aqueous solution interfaces as model system to disentangle different pH-dependent factors. In 0.1 M NaOH, HER current density Au(111) potential range −0.4 V < ERHE 0 up 60 times smaller than HClO4. A proper consideration local conditions within EDL developed. After correcting for effects, rate constant only weakly pH-dependent. Our analysis unambiguously reveals observed are mainly due reorganization free energy, which depends on electrostatic EDL. Possible origins temperature dependence activation energy electron transfer coefficients discussed. This work suggests factors influencing intrinsic kinetics easier understand after corrections effects.

Language: Английский

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Cation-Dependent Impact of CO₂ on Cu-Catalyzed Electrochemical CO Reduction Reaction

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(14), P. 10829 - 10838

Published: July 4, 2024

The electrochemical CO2 reduction reaction (CO2RR) on Cu occurs via two tandem steps, i.e., the CO2-to-CO conversion and CO (CORR). Thus, Cu-catalyzed CO2RR is, in fact, coelectrolysis of CO, which makes impact interfacial CORR a relevant factor determining overall performance. In this work, we report surprising observation that effect formation rate C2+ products depends nature cations electrolyte, beneficial with K+ Cs+ while inhibitory Li+ Na+. Density functional theory calculations indicate CO2δ− affects electrode-mediated reactions distinct modes opposite effects, general as an negatively charged species cation-specific promoting direct CO2-cation interactions. relative contributions these competing effects determine CORR. Furthermore, analysis isotopologue distributions mixtures 13CO/12CO2 reveals influence multiple steps CO2RR.

Language: Английский

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Quantum fundaments of catalysis: true electronic potential energy

Physical Chemistry Chemical Physics, Journal Year: 2024, Volume and Issue: 26(34), P. 22620 - 22639

Published: Jan. 1, 2024

Catalysis is a quantum phenomenon enthalpically driven by electronic correlations with many-particle effects in all of its branches, including electro-photo-catalysis and electron transfer. This means that only probability amplitudes provide complete relationship between the state catalysis observations. Thus, any atomic system material), competing space-time interactions coexist to define (related) properties such as stability, (super)conductivity, magnetism (spin-orbital ordering), chemisorption catalysis. Catalysts, reactants, chemisorbed transition states have possibility optimizing improve reaction kinetics. Active sites closed-shell orbital configurations share maximum number spin-paired electrons, mainly coulombic attractions covalency defining weakly correlated (WCCS) structures. However, compositions open-shell configurations, at least, spin exchange (QSEIopenshells) arise, stabilising unpaired electrons less covalent bonds differentiating non-weakly (or strongly) (NWCOS) systems. In NWCOS catalysts, ground can diverse rival spin-orbital orderings well ferro-, ferri- multiple antiferro-magnetic textures, which deeply their activities. Particularly inter-atomic ferromagnetic (FM) bonds, increase relevance non-classical potentials significantly optimize energies, (TSs), activation energies (overpotential) spin-dependent transfer (conductivity), overall implying need for explaining thermodynamic kinetic origin from true energy. To do so, we use connection Born-Oppenheimer approximation Virial theorem treatment potential energies. exact fundamental decompose TSs appear. The increasing stabilization TSs, due on NWCO opens simultaneously reducing enthalpies barriers mechanisms, implies anticipation explanation positive deviations Brønsted-Evans-Polanyi principle.

Language: Английский

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Electrolyte effects on the alkaline hydrogen evolution reaction: A mean-field approach

Electrochimica Acta, Journal Year: 2024, Volume and Issue: 497, P. 144530 - 144530

Published: June 7, 2024

This paper introduces the combination of an advanced double-layer model with electrochemical kinetics to explain electrolyte effects on alkaline hydrogen evolution reaction. It is known from experimental studies that current shows a strong dependence concentration and identity cations in electrolyte, but independent pH. To these effects, we formulate faradaic terms electric potential double layer, which calculated using mean-field takes into account cation anion sizes as well dipole moment water molecules. We propose Volmer step consists two activated processes: reduction sub-step, sub-step OH− transferred away reaction plane through layer. Either sub-steps may limit rate. The proposed models for qualitatively observations, including pH-independence, trend reversal between gold platinum electrodes. also assess quantitative accuracy water-reduction-limited model; suggest predicted functional relationship valid long bonding structure near electrode sufficiently maintained.

Language: Английский

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Unveiling the structure of interfacial water and its role in acidic and alkaline hydrogen evolution reaction at Au electrode by electrochemical in-situ infrared spectroscopy and theoretical simulation

Journal of Catalysis, Journal Year: 2025, Volume and Issue: 445, P. 116021 - 116021

Published: Feb. 16, 2025

Language: Английский

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