Surface diffusion on metals, semiconductors, and insulators

Seebauer, Edmund G.; Jung, M.Y.L.

doi:10.1007/10689660_30

Cited by 5 publications

(3 citation statements)

References 433 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using the LH-based kinetic model for CO 2 photoreduction (eq ), the rate-limiting step is the reaction between two adjacently occupied active sites on the photocatalyst surface. Increasing the probability of two adjacent active sites being occupied could be affected not only by the partial pressure of the adsorbing gases but also by the speed at which the reagent molecules move along the surface of the photocatalyst at different temperatures. , Poudyal investigated the impact of high temperature (250 and 350 °C) on CO 2 photoreduction using SiC and Si photocatalysts . The authors work was very useful as they took care with minimizing the probability of false positive results by using a metal-only reaction setup, multiple cleaning steps, and a comprehensive set of blank experiments to account for the effect of any organic impurities .…”

Section: Kinetic Model Approaches and The Impact Of Process Parameter...mentioning

confidence: 99%

Review and Analysis of CO₂ Photoreduction Kinetics

Thompson

Fernández

Maroto‐Valer

2020

ACS Sustainable Chem. Eng.

111

View full text Add to dashboard Cite

Microkinetic, in situ analytics, and empirical modeling approaches for developing intrinsic CO2 photoreduction kinetics are presented in this Perspective. Intrinsic kinetic models that are independent of photoreactor geometry are critical for scaling CO2 photoreduction photoreactors. Successfully scaling CO2 photoreduction is limited using the current extrinsic CO2 photoreduction kinetic models described in this Perspective, because they are dependent on the photoreactor geometry and scale used. The impact of different photoreactor geometries and light transport that lead to extrinsic kinetic models is reviewed. The impacts of temperature and pressure on surface diffusion is highlighted as additional important process parameters. The current Langmuir–Hinshelwood-based kinetic models are discussed, and their limitations are highlighted, with respect to modeling the possible deactivation of the photocatalyst. With a view on developing an intrinsic kinetic model, the challenges for developing CO2 photoreduction kinetics are highlighted and discussed with reference to the current extrinsic CO2 photoreduction kinetic model examples found in the literature. Robust analytical methods for collecting CO2 photoreduction kinetic data and for confirming the carbon source are discussed. The false positive production from adventitious carbon and organic impurities introduced during the synthesis and/or coating of photocatalysts with solvents and degradation of photoreactor components is highlighted as a challenge to collecting CO2 photoreduction kinetic data. It is shown that a wide range of the kinetic model coefficient values are possible when using a multistart, genetic algorithm, or particle swarm approach for estimating nonlinear model coefficients. Finally, an easy to test and implement approach using a mean median multistart and trust-region reflective algorithm method is presented for the estimation of nonlinear CO2 photoreduction kinetic model coefficients.

show abstract

Section: Kinetic Model Approaches and The Impact Of Process Parameter...mentioning

confidence: 99%

Review and Analysis of CO₂ Photoreduction Kinetics

Thompson

Fernández

Maroto‐Valer

2020

ACS Sustainable Chem. Eng.

111

View full text Add to dashboard Cite

show abstract

“…Several atomic processes on surfaces exhibit MNR behaviour. Some diffusion data were summarized by Zhdanov (1991) and more recently by Seebauer and Jung (2001) and by Barth (2000). During the past decade, methods for the study of surface diffusion on solids have become increasingly reliable, permitting accurate measurements of activation energies and prefactors (Barth 2000, Rosei 2004, Antonov et al 2004.…”

Section: Chemical Phenomenamentioning

confidence: 99%

Multi-excitation entropy: its role in thermodynamics and kinetics

2006

View full text Add to dashboard Cite

This review concerns the concept of multi-excitation entropy (MEE) and its consequences. When a fluctuation involving a large number of excitations occurs, for example, when a large activation barrier is overcome, there must be a large entropy associated with this fluctuation. First, the concepts of free energy and entropy, of activated processes and the Arrhenius and Eyring equations are reviewed. The tendency to neglect entropy, whose value is difficult to determine, in modelling kinetic processes, is briefly discussed. We then present a review of the experimental observations of the phenomenon which is variously known as the Compensation Law, the Isokinetic Rule and the Meyer-Neldel Rule (MNR). These observations include examples from chemistry, condensed matter physics, biology and geology. Arguments are then presented for the importance of entropy and particularly of MEE in both kinetics and thermodynamics, when activation energies are large. After a discussion of non-entropic models of compensation, we present results which support the MEE model as an explanation of MNR. The behaviour of systems with low activation energies, or at high temperatures, to which the MEE model does not apply, is then discussed.Several consequences of MEE, including applications to the interpretation of experimental data, particularly the unification of models of dc and ac electrical properties of materials are considered. The high temperature behaviour of systems which obey the MNR at low temperature is then explained, and the idea of a total entropy, of which the MEE is a part, is introduced, as is the correlation between the two empirical parameters encountered in MNR. Finally, these ideas lead to verified predictions of reasonable values of attempt frequencies and cross sections in kinetic processes, which initially appear unreasonable.

show abstract

“…Although surface diffusion phenomena are central to all of the foregoing experimental investigations, there is a paucity of measured data for surface diffusion coefficients. The existing data and methods of estimating values for surface diffusion coefficients have been reviewed 18,19 for a wide variety of systems that include metals, semiconductors and insulators. Of these, experimental data for surface diffusivities under liquid solution are reported for only a few systems involving pure metal (Au on Au and Pt on Pt).…”

mentioning

confidence: 99%

Numerical Scaling Studies of Kinetically-Limited Electrochemical Nucleation and Growth with Accelerated Stochastic Simulations

Bezzola

Bales

Petzold

et al. 2014

J. Electrochem. Soc.

View full text Add to dashboard Cite

A stochastic atomic-scale lattice-based numerical method based on the Exact Lattice First Passage Time method was developed for the simulation of the early stages of kinetically controlled electrochemical nucleation and growth. Electrochemical reaction and surface diffusion on a hexagonal lattice was accounted for in a pristine physical model system that included edge diffusion along steps, and movement over step edges with Ehrlich-Schwöbel barrier. Five cases were investigated: homoexpitaxy, heteroepitaxy, multi-layer growth, terraces, and confined regions. For each, the influence of the physical parameters, deposition conditions, and system geometry on growth morphology was investigated. Simulation based studies of multilayer surface morphology were able to distinguish between layer-by-layer and island growth modes. On stepped terraces, parameter regions associated with he surface diffusion to deposition flux ratio (D/F) and the Ehrlich-Schwöbel barrier were identified under which deposition occurred either at the step edge or by nucleation and growth of islands on the terraces. The probability of growing single crystals in a small confined region was found to scale with D/F and the radius squared.

show abstract

Surface diffusion on metals, semiconductors, and insulators

Cited by 5 publications

References 433 publications

Review and Analysis of CO₂ Photoreduction Kinetics

Review and Analysis of CO₂ Photoreduction Kinetics

Multi-excitation entropy: its role in thermodynamics and kinetics

Numerical Scaling Studies of Kinetically-Limited Electrochemical Nucleation and Growth with Accelerated Stochastic Simulations

Contact Info

Product

Resources

About

Surface diffusion on metals, semiconductors, and insulators

Cited by 5 publications

References 433 publications

Review and Analysis of CO2 Photoreduction Kinetics

Review and Analysis of CO2 Photoreduction Kinetics

Multi-excitation entropy: its role in thermodynamics and kinetics

Numerical Scaling Studies of Kinetically-Limited Electrochemical Nucleation and Growth with Accelerated Stochastic Simulations

Contact Info

Product

Resources

About

Review and Analysis of CO₂ Photoreduction Kinetics

Review and Analysis of CO₂ Photoreduction Kinetics