Adsorption of urea on the Pt(100) electrode: experiments and lattice-gas modeling

Gamboa-Aldeco, Maria; Mrozek, P.; Rhee, Choong Kyun; Wiȩckowski, Andrzej; Rikvold, Per Arne; Wang, Q.

doi:10.1016/0039-6028(93)90212-3

Cited by 34 publications

(57 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…40 The formation of this ordered structure has been studied previously by the group of Rikvold. 8,38,41 Their results could very well reproduce a c͑4 ϫ 2͒ ordered structure, as well as the sharp adsorption peak in the corresponding voltammogram. An interesting observation with regard to the model by these authors, is that in their c͑4 ϫ 2͒ ordered structure, the urea molecules are located two lattice vectors away from each other, but since each urea molecule binds through two nitrogen atoms, the distance between the nitrogen atoms of neighboring urea molecules is only one lattice vector.…”

Section: A Adsorption On the Fcc(100) Surfacesupporting

confidence: 54%

“…38,39 In the adsorption reaction two electrons are transferred per urea molecule, and the urea is bonded in a bridging fashion with both nitrogen atoms attached to the surface. The adsorption of urea coincides with the desorption of adsorbed hydrogen; the sharp voltammetric peak is thought to be due to the interactions between adsorbed urea and hydrogen during the conversion of the hydrogen atom adlayer into a urea adlayer.…”

Section: A Adsorption On the Fcc(100) Surfacementioning

confidence: 99%

See 1 more Smart Citation

Bridge-bonded adsorbates on fcc(100) and fcc(111) surfaces: A kinetic Monte Carlo study

et al. 2006

View full text Add to dashboard Cite

The adsorption of a bridge-bonded molecule onto fcc͑100͒ and fcc͑111͒ surfaces is studied using kinetic Monte Carlo simulations. The results are related to examples from both the electrochemical and the ultrahigh vacuum field. The lateral interaction model for the fcc͑100͒ surface with the least excluded neighbor sites does not cause ordering in the adlayer at saturation coverage. This is due to the availability of two equivalent bridge sites per surface atom. The model with the most excluded sites on the other hand causes the formation of a c͑4 ϫ 2͒ ordered structure with a coverage of 0.25 ML. Surprisingly, for the model with intermediate-ranged lateral interactions a one-dimensionally ordered structure is found. In this one-dimensionally ordered structure, bridge-bonded anions are aligned along the ͱ 2 direction. The spacing between these rows varies, since each new row can form at either one of the two kinds of bridge site per surface atom. The local distribution between these one-dimensional rows can be described by, respectively, a c͑2 ͱ 2 ϫ ͱ 2͒ or a ͑ ͱ 2 ϫ ͱ 2͒ unit cell ͓the latter one is also referred to as c͑2 ϫ 2͔͒. On the fcc͑111͒ surface, once again no ordered structure is found for the model with the smallest number of excluded sites. For the models with more excluded sites a c͑4 ϫ 2͒ ordered structure ͓also known as c͑2 ϫ ͱ 3͔͒ and a ͑ ͱ 3 ϫ ͱ 7͒ ordered structure are formed, the coverages being 0.50 and 0.20 ML, respectively. The simulated voltammograms generally show a broad peak due to adsorption in a disordered phase, and, if a two-dimensionally ordered structure is formed, a second sharp peak due to a disorder-order transition in the adlayer. The formation of the one-dimensionally ordered structure does not cause an additional current peak in the voltammogram.

show abstract

Section: A Adsorption On the Fcc(100) Surfacesupporting

confidence: 54%

Section: A Adsorption On the Fcc(100) Surfacementioning

confidence: 99%

Bridge-bonded adsorbates on fcc(100) and fcc(111) surfaces: A kinetic Monte Carlo study

et al. 2006

View full text Add to dashboard Cite

show abstract

“…which reduces to its standard form for α = 0 [19,[39][40][41]. We emphasize that the derivation of Eq.…”

Section: (T) Ssmentioning

confidence: 99%

“…These include mean-field approximations [87,88], Padé-approximant methods based on liquid theory [12,13,17,[21][22][23][24], numerical transfer-matrix calculations [33][34][35][36][37][38], and MC simulations [19,20,35,[39][40][41][42][43][44]. The reason for our choice of the numerical MC method [30][31][32] is that such non-perturbative methods as MC and transfer-matrix calculations provide much more accurate results for two-dimensional systems than even quite sophisticated mean-field approximations [89].…”

Section: B Simulations At Room Temperaturementioning

confidence: 99%

“…Using group-theoretical ground-state calculations at zero temperature [27][28][29] and Monte Carlo (MC) simulations at room temperature [30][31][32], we estimate the model parameters (the effective, lateral interactions and electrovalences) so as to obtain overall agreement with the available experimental data, including both our own and those of other groups. This theoretical approach has previously been applied to electrochemical problems by Rikvold and co-workers [33][34][35][36][37], and it was most recently used to model the coadsorption of hydrogen with urea on single-crystal platinum (100) electrodes [19,[38][39][40][41][42][43] and with sulfate on rhodium (111) [19]. It differs from the approach taken by HB in that we apply the full, two-component lattice-gas model to analyse global , as well as local features of the system's phase diagram and CV current profiles, and in that our room-temperature results are obtained by nonperturbative, numerical simulation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Underpotential deposition of Cu on Au(111) in sulfate-containing electrolytes: A theoretical and experimental study

Zhang

Sung

Rikvold

et al. 1996

The Journal of Chemical Physics

View full text Add to dashboard Cite

We study the underpotential deposition of Cu on single-crystal Au(111) electrodes in sulfate-containing electrolytes by a combination of computational statistical-mechanics based lattice-gas modeling and experiments. The experimental methods are in situ cyclic voltammetry and coulometry and ex situ Auger electron spectroscopy and low-energy electron diffraction. The experimentally obtained voltammetric current and charge densities and adsorbate coverages are compared with the predictions of a two-component lattice-gas

show abstract

Electrochemical Urea Oxidation in Different Environment: From Mechanism to Devices

Wang

Duan

et al. 2022

ChemCatChem

View full text Add to dashboard Cite

Urea has been regarded as an important chemical compound in the food‐water‐energy nexus. However, the emission of urea from human activity, industrial manufacture, and agricultural fertilization into the environment has caused an ecological nitrogen imbalance. Besides addressing the environmental pollution, the applications of clean energy conversion from urea‐rich wastewater has strong potential for resource and energy recovery. Herein, we conducted a comprehensive overview of electrochemical urea oxidation reaction (UOR) for pollution control and energy harvesting. The present mechanisms and behaviors of UOR under different water matrices have been characterized and compared in detail. Additionally, the latest development of electrochemical UOR integrated into electrolyzers and fuel cells are presented. Finally, we discuss the prospects and challenges of UOR technologies, suggesting several directions for the electrochemical conversion of urea‐abundant wastewater in the near future.

show abstract

Adsorption of urea on the Pt(100) electrode: experiments and lattice-gas modeling

Cited by 34 publications

References 24 publications

Bridge-bonded adsorbates on fcc(100) and fcc(111) surfaces: A kinetic Monte Carlo study

Bridge-bonded adsorbates on fcc(100) and fcc(111) surfaces: A kinetic Monte Carlo study

Underpotential deposition of Cu on Au(111) in sulfate-containing electrolytes: A theoretical and experimental study

Electrochemical Urea Oxidation in Different Environment: From Mechanism to Devices

Contact Info

Product

Resources

About