surfacekinetic

Surfacekinetic refers to the study of rates and mechanisms of processes that occur at surfaces and interfaces, typically solid–gas or solid–liquid boundaries. Core processes include adsorption of species onto a surface, desorption back into the surrounding phase, surface diffusion of adsorbed species, and reactions that take place on the surface, such as catalytic or electrochemical steps. A central concept is surface coverage, theta, representing the fraction of available surface sites occupied by adsorbates. Kinetics are described by rate equations that incorporate temperature-dependent rate constants, often following Arrhenius behavior, and by site balance constraints.

Common modeling frameworks include Langmuir adsorption with r_ads = k_ads P (1 − theta) and r_des = k_des theta; for surface reactions, Langmuir–Hinshelwood and Eley–Rideal mechanisms illustrate how adsorbed species react or how a gas-phase atom reacts directly with a surface-adsorbed species. Microkinetic models decompose overall rates into elementary steps to predict coverages, rates, and selectivities.

Experimental techniques such as temperature-programmed desorption, infrared spectroscopy, and sum-frequency generation, alongside theoretical tools like density functional theory and kinetic Monte Carlo, support the determination of rate constants and mechanisms. Applications span heterogeneous catalysis, fuel cells, corrosion, sensors, and semiconductor processing.

Challenges include surface heterogeneity, reconstruction, lateral interactions between adsorbates, and kinetic delays across nano- to macroscale regimes. Surfacekinetic remains essential for understanding and optimizing processes where the surface behavior governs overall rate and outcome.