Modeling of electron transfer across electrochemical interfaces: State‐of‐the art and challenges for quantum and computational chemistry

Abstract

State-of-the-art in the area of quantum-chemical modeling of electron transfer (ET) processes at metal electrode/electrolyte solution interfaces is reviewed. Emphasis is put on key quantities which control the ET rate (activation energy, transmission coefficient, and work terms). Orbital overlap effect in electrocatalysis is thoroughly discussed. The advantages and drawbacks of cluster and periodical slab models for a metal electrode when describing redox processes are analyzed as well. It is stressed that reliable quantitative estimations of the rate constants of interfacial charge transfer reactions are hardly possible, while predictions of qualitatively interesting effects are more valuable.

Understanding the structure and reactivity of NiCu nanoparticles: an atomistic model

“…This is the reason why the best catalysis in the electrochemical hydrogen oxidation takes place at a certain (compromise) surface structure which results basically from the copper segregation. A more comprehensive treatment of the mechanism of hydrogen oxidation at the bimetallic nanoparticle surface should rest on a combination of the quantum mechanical theory of charge transfer with molecular modeling [52]; work which is in progress and will be addressed in a future contribution, as well a natural extension of our work to study the effect of the solvent.…”

Electronic Spillover from a Metallic Nanoparticle: Can Simple Electrochemical Electron Transfer Processes Be Catalyzed by Electronic Coupling of a Molecular Scale Gold Nanoparticle Simultaneously to the Redox Molecule and the Electrode?

“…The dominating effect of the orbital overlap is then to decrease the ET activation barrier and in this way accelerate the reaction, most conveniently further addressed using the Anderson−Newns formalism. 59 2.2. Coherence and Incoherence in (Bio)electrochemical NP-Mediated Two-Step ET.…”

“…We can also represent eq as where ω eff is the effective vibrational frequency of all the classical nuclear modes reorganized and The adiabatic limit takes over when [ T (ε F )] 2 ρ­(ε F ) k B T ≈ 10 –4 eV 2 . The dominating effect of the orbital overlap is then to decrease the ET activation barrier and in this way accelerate the reaction, most conveniently further addressed using the Anderson–Newns formalism …”

Influence of the NaOH Concentration on the Hydrogen Electrode Reaction Kinetics of Ni and NiCu Electrodes

“…The height of the activation barrier depends on a number of parameters, such as the solvent reorganization energy l, the Gibbs energy of H adsorption, the coupling parameter Δ in terms of the Anderson-Newns model (see Ref. [56] for details) and electrode overpotential η. At a given η the ET rate constant in the adiabatic limit is thus affected by: (i) the distance of the closest approach (x 0 ), (ii) the frequency factor, (iii) the work term, (iv) the solvent reorganization energy, (v) the coupling parameter Δ (the larger the Δ, the smaller the energy barrier), and (vi) the hydrogen adsorption Gibbs energyDG H ad ð Þ.…”