Kink Sites Research Articles

Mechanism of Interlayer Transport on a Growing Au(111) Surface: 2D vs. 3D Growth

The atomic scale transitions corresponding to diffusion and interlayer transport of a Au adatom on the low energy, close packed Au(111) surface are studied using density functional theory calculations within the generalized gradient approximation. Minimum energy paths and estimates of activation energy are calculated for processes that influence whether the crystal grows layer-by-layer, i.e. 2D growth, or whether new islands tend to nucleate on top of existing islands resulting in 3D growth. Kinks on island edges turn out to provide paths for adatom descent with lower activation energy than straight steps. The energy barrier for an adatom to round the corner and enter a kink site is significantly higher. A descent mechanism that places an adatom near but not at a kink site can therefore promote the formation of a new row of step atoms and lead to the introduction of additional kink sites, thereby opening up new low activation energy paths for descent and promotion of 2D growth. The sites adjacent and above the step edge provide large binding energy for the adatom, especially at the B-type step, and form a trough along which the adatom can migrate before descending, thereby increasing the probability that an adatom finds a kink on the B-type step. These features of the energy landscape representing the interaction of a Au adatom with the surface point to the possibility of a re-entrant layer-by-layer growth mode of the low energy, close packed surface of the gold crystal.

Desorption trends of small alcohols and the disruption of intermolecular interactions at defect sites on Au(111).

Gold-based catalysts have received tremendous attention as supports and nanoparticles for heterogeneous catalysis, in part due to the ability of nanoscale Au to catalyze reactions at low temperatures in oxidative environments. Surface defects are known active sites for low temperature Au chemistry, so a full understanding of the interplay between intermolecular interactions and surface morphology is essential to an advanced understanding of catalytic behavior and efficiency. In a systematic study to better understand the adsorption and intermolecular behavior of small alcohols (C1-C4) on Au(111) defect sites, coverage studies of methanol, ethanol, 1-propanol, 1-butanol, 2-butanol, and isobutanol have been conducted on Au(111) using ultrahigh vacuum temperature programmed desorption (UHV-TPD). These small alcohols molecularly adsorb on the Au(111) surface and high resolution experiments reveal distinct terrace, step edge, and kink adsorption features for each molecule. The hydrogen-bonded (H-bonded) networks of small alcohols on Au(111), except for 1-butanol and isobutanol, have been previously imaged on the molecular level at low temperatures by scanning tunneling microscopy. Primary C1-C3 alcohols exhibit planar H-bonded long extended zigzag chain networks while 2-butanol arranges in tetramer clusters of H-bonded molecules due to steric hindrance inhibiting the proximity of molecules on Au(111). Herein, the desorption energy of small primary alcohols was shown to trend linearly with increasing C1-C4 carbon chain length, indicating that the H-bonded molecular packing of 1-butanol resembles that of methanol, ethanol, and 1-propanol, while isobutanol and 2-butanol deviate from the trend. Butanol isomer studies allow the prediction of isobutanol long extended chains in contrast to tetramers. The distinction between the desorption of butanol isomers highlights the role of intermolecular interactions due to the difference in molecular packing structures on Au(111). Furthermore, by studying the energetics of terrace H-bonded networks in comparison with molecular adsorption at undercoordinated step edge and kink defect sites, it is shown that the contribution of stabilizing van der Waals forces to the overall adsorption energy is less for small alcohols adsorbed at kink sites (3.1 kJ mol-1 per CH2) and similar for those adsorbed at step edge (4.8 kJ mol-1 per CH2) and Au terrace sites (4.9 kJ mol-1 per CH2).

Seed-directed synthesis of chiroptically active Au nanocrystals of varied symmetries.

Chiral plasmonic nanocrystals with varied symmetries were synthesized by L-glutathione-guided overgrowth from Au tetrahedra, nanoplates, and octahedra, highlighting the importance of chiral molecule adsorption at transient kink sites. Large g-factors are possible and depend on symmetry. Simulations of their chiroptical properties from tomographically obtained nanocrystal models further verify their chirality.

Structure-dependent adsorption and desorption of hydrogen on FCC and HCP cobalt surfaces

The interaction of hydrogen with cobalt surfaces is of fundamental interest for Fischer-Tropsch synthesis. In the present work, the adsorption and desorption of hydrogen was studied on various cobalt single crystal surfaces that together represent the surface structures exposed by FCC and HCP cobalt nanoparticles used in applied catalysis. Dissociative hydrogen adsorption is activated on flat Co(0001), especially for hydrogen coverages beyond 0.5 ML. A tungsten filament creates hydrogen atoms and hot hydrogen molecules that increase the dissociative sticking probability and make it possible to obtain hydrogen coverages above 0.5 ML. Hydrogen in excess of 0.5 ML binds more weakly and desorbs in a separate low temperature desorption peak, in line with theoretical predictions. A third desorption peak appears above 1 ML and is attributed to subsurface hydrogen, the formation of which is attributed to hydrogen atoms produced by the tungsten filament. Adsorbed hydrogen atoms form (islands) of an ordered (2 × 2)-2H honeycomb structure for coverages between 0.3 and 0.8 ML which points to a specific stability of this structure. Step and kink sites on vicinal close-packed surfaces provide a low energy path for both hydrogen adsorption and desorption which results in a much higher dissociative sticking probability and a lower desorption temperature. The hydrogen adsorption strength on various FCC and HCP cobalt surfaces varies between 30 and 45 kJ/mol Had and is strongest on threefold hollow sites on the close-packed terraces while it is significantly lower on fourfold hollow sites on FCC-(100) and on threefold hollow sites on various open HCP surfaces. Under reaction conditions, the structure-dependent adsorption energy translates to a two to three orders of magnitude variation of the equilibrium constant for hydrogen.

Ba attachment and detachment fluxes to and from barite surfaces in 137Ba-enriched solutions with variable [Ba2+]/[SO42−] ratios near solubility equilibrium

We measured barium attachment and detachment fluxes from and to barite crystal surfaces in solutions with [Ba]/[SO4] ratios from 0.06 to 52. The doping of 137Ba in the initial experimental solutions enabled us to measure unidirectional fluxes near solubility equilibrium (Q/K ≈ 1.0) in batch reactors. Both attachment and detachment fluxes increase with [Ba]/[SO4] ratios. As expected, since the solutions were near solubility equilibrium (SI≈0.0n), the attachment and detachment fluxes were nearly equal.The experimental data can be fit accurately using the Zhang and Nancollas (1998) (ZN98) process-based AB crystal growth model, which describes crystal growth and dissolution through nucleation and propagation of kink sites. Simultaneous fitting step velocity data of Kowacz et al. (2007) significantly reduced the number of non-uniqueness solutions. The remarkable fit implies that barite recrystallization at room temperature near equilibrium and moderate supersaturation occurs via ion-by-ion addition and removal, rather than the formation of amorphous precursors or aggregation of particles. The model is best fit using different detachment frequencies for Ba and SO4, suggesting the ZN98 assumption that detachment frequencies should be the same for the constituent ions does not apply to barite. Based on experimental data and model fitting, Ba attachment and detachment fluxes at a fixed saturation state increase with [Ba]/[SO4] ratios monotonically. This has potentially significant implications for interpreting isotope and trace element cycling in natural environments.

Adsorption of CO2 on Terrace, Step, and Defect Sites on Pt Surfaces: A Combined TPD, XPS, and DFT Study

The interactions of CO2 with terrace, step, and defect or kink sites on Pt surfaces were investigated using temperature-programmed desorption, X-ray photoelectron spectroscopy, and density functional theory calculations. Desorption peaks of CO2 on Pt(997) were observed at ∼79, 88–89, ∼92 , and ∼103 K and were respectively assigned to desorption of CO2 from multilayer CO2 (amorphous CO2), CO2 from terrace, CO2 from step, and CO2 from defect sites. The defect sites, step sites, and terrace sites were saturated in that order before multilayer adsorption occurred. The adsorption energies of CO2 on the terrace, step, and defect sites were estimated to be around −0.23, −0.28, and −0.34 eV, respectively. The experimentally measured adsorption energies of CO2 on Pt were successfully reproduced using the optB86b-vdW, rev-vdW-DF2, and PBE-D2 functionals, and the actual adsorption energies were found to be between those calculated with rev-vdW-DF2 and optB86b-vdW. Additionally, it was found that CO2 adsorption is energetically more stable at higher CO2 coverage than at lower coverage because of CO2–CO2 lateral attractive interactions.

Morphological Stability of Copper Surfaces under Reducing Conditions.

Though copper is a capable electrocatalyst for the CO2 reduction reaction (CO2RR), it rapidly deactivates to produce mostly hydrogen. A current hypothesis as to why this occurs is that potential-induced morphological restructuring takes place, leading to a redistribution of the facets at the interface resulting in a shift in the catalytic activity to favor the hydrogen evolution reaction over CO2RR. Here, we investigate the veracity of this hypothesis by studying the changes in the voltammetry of various copper surfaces, specifically the three principal orientations and a polycrystalline surface, after being subjected to strongly cathodic conditions. The basal planes were chosen as model catalysts, while polycrystalline copper was included as a means of investigating the overall behavior of defect-rich facets with many low coordination steps and kink sites. We found that all surfaces exhibited (perhaps surprisingly) high stability when subjected to strongly cathodic potentials in a concentrated alkaline electrolyte (10 M NaOH). Proof for morphological stability under CO2RR-representative conditions (60 min at −0.75 V in 0.5 M KHCO3) was obtained from identical location scanning electron microscopy, where the mesoscopic morphology for a nanoparticle-covered copper surface was found unchanged to within the instrument accuracy. Observed changes in voltammetry under such conditions, we found, were not indicative of a redistribution of surface sites but of electrode fouling. Besides impurities, we show that (brief) exposure to oxygen or oxidizing conditions (i.e., 1 min) leads to copper exhibiting changing morphology upon cathodic treatment which, we posit, is ultimately the reason why many groups report the evolution of copper morphology during CO2RR: accidental oxidation/reduction cycles.

Simulations of Dissolution of Initially Flat Calcite Surfaces: Retreat Velocity Control and Surface Roughness Scaling

The far-from-equilibrium alkaline dissolution of initially flat and defect-free calcite surfaces is modeled with kinetic Monte Carlo simulations of site detachment from a Kossel crystal and with scaling approaches. The surface retreat velocity is strongly dependent on the detachment rate of the highest coordination sites, which represent molecules in the middle of (101̅4) terraces. The comparison with a recent velocity estimate from digital holographic microscopy predicts the removal rate of those molecules between 2 × 10–7 and 4 × 10–6 s–1 at room temperature, which improves a previous estimate from a grain dissolution model. The activation energy for this molecular-scale process is estimated as 92 ± 6 kJ/mol (assuming the same prefactor ∼3 × 1010 s–1 of kink and step sites). The areal density of nonterrace sites (mostly steps and kinks) is also related to that removal rate, so we propose that the measurement of this density may provide independent estimates of the above quantities. Arrhenius plots of the retreat velocities obtained in high-temperature simulations predict the (macroscopic) activation energy of 69 ± 4 kJ/mol for dissolution of smooth surfaces. We also show that the scaling of the surface roughness in time and size is the same as in the Kardar–Parisi–Zhang (KPZ) equation of kinetic roughening. However, room-temperature roughening of initially smooth calcite surfaces is so slow that it is unlikely to be observed in typical experimental times and the alkaline conditions modeled here. Since the rates in acidic media are larger and arguing that the microscopic symmetries of the molecule detachment processes should be preserved, we suggest the investigation of KPZ scaling under those conditions.

High-index planes T-Nb2O5 using self-assembly strategy for aerobic oxidative desulfurization in fuels

High-index planes viewed as reactive facets are possessed of the high-density, low-coordination atoms, which are distributed at catalytic sites with high activity, such as steps, edges and kink sites. Herein, the orthorhombic niobium pentoxide (T-Nb2O5) is synthesized, with the elevated ratio of high-index planes, first for aerobic oxidative desulfurization (ODS) of the refractory aromatic sulfides. Through a solvent evaporation-induced self-assembly strategy, mesoporous structure Nb2O5 with three different crystal phases, amorphous, pseudo-hexagonal and orthorhombic, are prepared using the calcination method. The proportion of high-index facets increases, as raising the calcination temperature, which contributes to the faster production of the superoxide free radical (•O2–) intermediate using molecular oxygen as the green oxidant. Under optimal conditions, a 100% sulfur removal rate is obtained using 650 °C-T-Nb2O5 within 7 h, showing its excellent catalytic performance. The cycle experiments confirm the stability of the prepared 650 °C-T-Nb2O5 after 8 times regeneration process, showing a promising prospect of NbOx-based materials for ODS under mild conditions.

Cryo-EM analysis provides new mechanistic insight into ATP binding to Ca2+ -ATPase SERCA2b.

Sarco/endoplasmic reticulum Ca2+ -ATPase (SERCA) 2b is a ubiquitous SERCA family member that conducts Ca2+ uptake from the cytosol to the ER. Herein, we present a 3.3Å resolution cryo-electron microscopy (cryo-EM) structure of human SERCA2b in the E1·2Ca2+ state, revealing a new conformation for Ca2+ -bound SERCA2b with a much closer arrangement of cytosolic domains than in the previously reported crystal structure of Ca2+ -bound SERCA1a. Multiple conformations generated by 3D classification of cryo-EM maps reflect the intrinsically dynamic nature of the cytosolic domains in this state. Notably, ATP binding residues of SERCA2b in the E1·2Ca2+ state are located at similar positions to those in the E1·2Ca2+ -ATP state; hence, the cryo-EM structure likely represents a preformed state immediately prior to ATP binding. Consistently, a SERCA2b mutant with an interdomain disulfide bridge that locks the closed cytosolic domain arrangement displayed significant autophosphorylation activity in the presence of Ca2+ . We propose a novel mechanism of ATP binding to SERCA2b.

Solubility Prediction of Organic Molecules with Molecular Dynamics Simulations

We present a molecular dynamics simulation method for the computation of the solubility of organic crystals in solution. The solubility is calculated based on the equilibrium free energy difference between the solvated solute and its crystallized state at the crystal surface kink site. To efficiently sample the growth and dissolution process, we have carried out well-tempered metadynamics simulations with a collective variable that captures the slow degrees of freedom, namely, the solute diffusion to and adsorption at the kink site together with the desolvation of the kink site. Simulations were performed at different solution concentrations using constant chemical potential molecular dynamics, and the solubility was identified at the concentration at which the free energy values between the grown and dissolved kink states were equal. The effectiveness of this method is demonstrated by its success in reproducing the experimental trends of solubility of urea and naphthalene in a variety of solvents.

Deciphering the role of Ni particle size and nickel-ceria interfacial perimeter in the low-temperature CO2 methanation reaction over remarkably active Ni/CeO2 nanorods

The structure sensitivity of CO2 methanation was explored over nickel particles (10–25 nm) supported on CeO2 nanorods. An optimum Ni particle size of 20 nm was revealed, with the corresponding sample demonstrating remarkable activity, i.e., 187 μmol CH4 g−1 s−1 and 92 % CH4 yield at 275 °C, which is among the highest ever reported. Notably, the intrinsic activity on the basis of the exposed Ni sites or Ni-ceria perimeter is largely independent of the Ni size, showcasing that neither the exposed Ni sites nor the Ni-ceria interface can be employed as activity descriptors. A compromise between the length of the metal-support perimeter and the competitive presence of larger Ni particles is necessary for the optimum activity. On the grounds of a structure-sensitivity analysis, the superior activity of larger Ni particles could be attributed to the presence of under-coordinated step and kink sites, instead of largely inactive terrace sites.

Influence of Muscovite (001) Surface Nanotopography on Radionuclide Adsorption Studied by Kinetic Monte Carlo Simulations

Mechanistic understanding and prediction of solute adsorption from fluids onto mineral surfaces is relevant for many natural and technical processes. Mineral surfaces in natural systems are often exposed to fluids at non-equilibrium conditions resulting in surface dissolution reactions. Such reactions cause the formation of surface nanotopography and, consequently, the exposure of different types of surface atoms. The quantitative effect of nanotopography on the efficiency of adsorption reactions at crystal surfaces is not known. Using kinetic Monte Carlo simulations, we combined a model of muscovite (001) face dissolution with a consequent model of radionuclide adsorption on the rough mineral surface. The model considers three different adsorption sites based on the muscovite surface cations: silicon, tetrahedral, and octahedral aluminum. Two different nanotopography configurations are investigated, both showing similar adsorption behavior. Octahedral aluminum surface atoms defined by having the highest reactivity toward adsorption are exposed solely on steps and pits on the muscovite (001) face. Thus, their availability directly depends on the surface nanotopography. The model results show the need for a more precise parameterization of surface site-specific adsorption, taking into account the coordination of the involved surface cation such as kink, step, or terrace sites.

A mechanistic software platform for mineral surface deposition and inhibition prediction under different flow conditions

Unexpected mineral surface fouling, or deposition, is a ubiquitously recurring problem in many industrial and municipal processes (e.g., membrane filtration, oil and gas production). Accurate predictions of mineral deposition and inhibition kinetics are critical for mineral deposition control. Unfortunately, no reliable mineral deposition model is available, potentially due to insufficient knowledge of thermodynamics, crystallization and deposition kinetics, and inhibition kinetics under complex operational conditions. This study developed a new mineral surface deposition and inhibition (MSDI) platform to overcome these challenges. Specifically, the MSDI platform integrates a Pitzer theory-based thermodynamic model that can predict mineral saturation levels up to 250 °C, 1500 bars, and 6 mol/kg H2O ionic strength. It simulates mineral deposition in two phases. In Phase 1, the first deposition layer forms in the stagnant laminar sublayer following batch crystallization and inhibition kinetics; in Phase 2, the deposition rate is simulated using flow dynamic models, and the inhibitor impacts are modelled by a Langmuir-type kink site adsorption isotherm. This MSDI platform has been validated by laboratory laminar-to-turbulent flow experiments and field observations. As one of the few mineral deposition prediction tools, the MSDI platform has solid theoretical foundation with great accuracy over wide ranges of applicable conditions.

The influence of Ca:CO3 stoichiometry on Ca isotope fractionation: Implications for process-based models of calcite growth

The solution stoichiometry dependence of calcium isotope fractionation during calcite precipitation was investigated as a direct test of the conceptual model of calcium isotope discrimination driven by Ca exchange at surface sites during growth. Classical ion-by-ion models of calcite growth predict a strong solution stoichiometry influence on Δ44/40Cacalcite-fluid: In low Ca2+:CO32–solutions,Δ44/40Cais predicted to approach a kinetic limit (∼−2 to −4‰), while in high Ca2+:CO32–solutions, exchange at dominantly Ca-occupied kink sites drives Δ44/40Catowards the equilibrium fractionation (near 0‰). To test thisprediction,a series ofseeded and unseeded constant composition calcite growth experiments were performed in which all aspects of solution chemistry were held constant and the Ca2+:CO32– activity ratio was varied. Experiments were performed at pH 8.5, ionic strength 0.1 M (adjusted with KCl), and calcite saturation index (SI = log10({Ca2+}{CO32–}/Ksp)) of either 0.5 or 0.8.Calcium isotope fractionation is found to be weakly stoichiometry dependent. The expected trend of larger magnitude fractionations at lower Ca2+:CO32– is observed, but the magnitude of change in Δ44/40Ca over the solution stoichiometries studied (Ca2+:CO32– = 1–250) is only ∼ 0.4‰. Similar trends in Δ44/40Ca with Ca2+:CO32– are observed at SI = 0.5 and 0.8, with smaller magnitude fractionations at lower supersaturation. This yields an inverse correlation between Δ44/40Ca and growth rate, confirming the Δ44/40Ca-rate relationship for inorganic calcite growth observed by Tang et al. (2008). The ion-by-ion model framework captures measured Δ44/40Ca only when a surface complexation model is incorporated, highlighting the role of surface speciation in dictating Ca attachment/detachment dynamics. The model captures observed trends with Ca2+:CO32– using best-fit kinetic and equilibrium fractionations consistent with end-members observed in natural systems (αkinetic ∼ 0.9978, αeq ∼ 0.9998). This result implies a total possible range in Δ44/40Ca of 2‰ and suggests that for most carbonate precipitating environments, solution supersaturation will be a stronger determinant of Δ44/40Ca than stoichiometry. The demonstrated importance of surface speciation, however, implies a strong pH influence on Δ44/40Ca, independent of its influence on carbonate ion activity, that requires further investigation.The results of this study provide strong evidence supporting the model of kink-exchange driven Ca isotope fractionation and suggest that calcite grows by a dominantly classical mechanism over the solution conditions investigated. Model predictions regarding the relationship between Δ44/40Ca and growth inhibition in the presence of impurity ions lay the foundation for the use of Ca isotopes as molecular tracers of carbonate crystal growth pathways.

CO organization at ambient pressure on stepped Pt surfaces: first principles modeling accelerated by neural networks.

Step and kink sites at Pt surfaces have crucial importance in catalysis. We employ a high dimensional neural network potential (HDNNP) trained using first-principles calculations to determine the adsorption structure of CO under ambient conditions (T = 300 K and P = 1 atm) on these surfaces. To thoroughly explore the potential energy surface (PES), we use a modified basin hopping method. We utilize the explored PES to identify the adsorbate structures and show that under the considered conditions several low free energy structures exist. Under the considered temperature and pressure conditions, the step edge (or kink) is totally occupied by on-top CO molecules. We show that the step structure and the structure of CO molecules on the step dictate the arrangement of CO molecules on the lower terrace. On surfaces with (111) steps, like Pt(553), CO forms quasi-hexagonal structures on the terrace with the top site preferred, with on average two top site CO for one multiply bonded CO, while in contrast surfaces with (100) steps, like Pt(557), present a majority of multiply bonded CO on their terrace. Short terraced surfaces, like Pt(643), with square (100) steps that are broken by kink sites constrain the CO arrangement parallel to the step edge. Overall, this effort provides detailed analysis on the influence of the step edge structure, kink sites, and terrace width on the organization of CO molecules on non-reconstructed stepped surfaces, yielding initial structures for understanding restructuring events driven by CO at high coverages and ambient pressure.

Frosting and defrosting on the hydrophilic nylon-6 nanofiber membrane–coated surfaces

Ice formation on various surfaces causes catastrophic consequences or enormous economic losses. Superhydrophobic surfaces with extreme water repellency were applied for removing ice efficiently; however, their practical applications are hindered by the fabrication of the complicated micro/nanostructures of the surfaces. In this work, we proposed using hydrophilic nylon-6 nanofiber membrane coating for enhancing deicing. The nylon-6 nanofiber membrane can be easily made by electrospinning. Given the abundant kink sites provided by a large number of ice nucleation sites on the membrane, the formed ice layer could be removed quickly in the deicing process on the membrane-coated surfaces. The total time required for the ice to completely dissipated has decreased by 80% compared with a noncoated surface. The substantially enhanced deicing ability of the nylon-6 nanofiber membrane indicates its potential for practical applications.

Modeling the kinetics of calcite dissolution in neutral and alkaline solutions

Using kinetic Monte Carlo simulations and scaling approaches, we describe the far from equilibrium calcite dissolution in neutral to alkaline solution and in scales ranging from the molecule detachment from surfaces to that of crystalline grains. The parameters of the thermally activated model are calibrated by the velocities of terrace steps and densities of monolayer pits measured in atomic force microscopy works. The application to nanosized crystalline grains shows that they dissolve at room temperature with significant edge rounding, large rates compared to laboratory estimates, and activation energy equal to that of molecule detachment at kink sites. A different kinetic regime is predicted for grains with typical macroscopic sizes or for high temperatures, in which pit nucleation at flat surfaces and step retreat lead to more uniform dissolution. The extrapolation of high temperature simulation data to room temperature gives dissolution rate 0.3–1.4 μmol/(m2 s) and activation energy 64±3 kJ/mol for macroscopic grains with various densities of surface steps. This rate agrees with the smallest values obtained in a recent compilation of laboratory data in alkaline conditions and the activation energy agrees with laboratory estimates. Grains with high densities of kink sites are shown to dissolve with rates ∼101-102 times larger; these estimates are used to predict the contribution of dislocations and explain the largest values of that compilation.

Step-edge and kink segregation models for analysis of reported step-velocity dependences of carbon concentration in GaN

The correlation between step velocity and carbon incorporation during the step-flow growth of GaN was analyzed from the standpoints of the meantime until a carbon atom incorporated at the kink site moves through the step-edge site to the surface site, τ, and the length of time before the carbon concentration at the step-edge site reaches its equilibrium value, τstep. Reported step-velocity dependences of carbon concentration in GaN were successfully reproduced with the assumption of τ ≫ τstep or τ < τstep. Due to the difficulty in estimating τstep, additional experiments are needed to tell which segregation is dominant for carbon in GaN.

Effect of undercoordinated Ag(111) defect sites on the adsorption of ethanol

In recent years, the use of silver-based materials for selective and highly active ethanol reactivity in single atom catalysis and the ethanol oxidation reaction in direct fuel cells highlights the importance of silver (Ag) in an ethanol economy. Understanding the interaction of ethanol with Ag(111) and the natural defects found on extended Ag(111) is critical to the overall understanding of more complex catalytic processes including ethanol activation over Ag-based catalysts. The research herein aims to characterize the interaction of ethanol molecules on undercoordinated defect sites of Ag(111) to mimic active sites found on Ag nanoparticle catalysts. The interaction between ethanol and Ag(111) was studied using temperature programed desorption (TPD), x-ray photoelectron spectroscopy, and density functional theory (DFT). Molecular ethanol adsorption and desorption from Ag(111) and the distinction between undercoordinated Ag(111) adsorption sites were determined using TPD in correlation with DFT. Complete analysis of TPD data for ethanol adsorbed to terrace sites was used to calculate a kinetic prefactor (3.4 × 1015) and desorption energy (0.54 eV). A better understanding of defect-dependent behavior for ethanol on silver can lead to a greater insight into high surface area nanoparticle catalysts used in industries, catalytic converters, and photo-, electro-, and heterogeneous catalysis. The results suggest that ethanol preferentially adsorbs to undercoordinated sites on Ag(111), resulting in higher binding energies for these molecules (Redhead first order approximation for desorption energies is terrace, 0.54 eV; step edge, 0.57 eV; and kink sites, 0.61 eV). Furthermore, alteration of the silver surface can lead to a redistribution of these sites.