Related Experiment Video
Updated: Oct 17, 2025
10:52
Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
13.0K
Oscillatory dynamics during the methanol electrooxidation reaction on Pt(111)
Kaline Nascimento da Silva1, Elton Sitta1,2
1Chemistry Department, Federal University of Sao Carlos, Rod. Washington Luis, km 235, Sao Carlos, 13565-905, Brazil. esitta@ufscar.br.
Physical Chemistry Chemical Physics : PCCP
|October 13, 2021
Summary
We observed oscillatory methanol electrooxidation on single-crystal Pt(111) surfaces. Sulfate presence inhibits these oscillations, offering insights into catalyst surface dynamics.
Area of Science:
- Electrochemistry
- Surface Science
- Catalysis
Background:
- The oscillatory methanol electrooxidation reaction (OMOR) is well-documented on polycrystalline platinum but less understood on single-crystal surfaces.
- Dynamic instabilities in electrocatalysis are crucial for understanding reaction mechanisms and optimizing catalyst performance.
Purpose of the Study:
- To investigate the oscillatory methanol electrooxidation reaction (OMOR) on a single-crystal Pt(111) surface.
- To map these oscillations in non-adsorbing anion solutions and in the presence of sulfate anions.
- To elucidate the role of surface structure and anion adsorption in OMOR dynamics.
Main Methods:
- Electrochemical measurements were performed on a Pt(111) single crystal electrode.
- Methanol electrooxidation was studied in solutions with varying methanol concentrations and the presence of sulfate anions.
- Electrochemical data, including potential and current, were analyzed to identify and characterize oscillatory behavior and surface intermediate accumulation.
Main Results:
- Period 1 oscillations (1.2–2.0 Hz) were observed for methanol concentrations >1.0 M on Pt(111) in non-adsorbing anion solutions.
- Oscillations occurred in a potential range where PtOH partially covered the surface, avoiding irreversible oxidation.
- A 'drift' in mean potential and poisoning rate was observed, attributed to intermediate accumulation.
- Sulfate anions significantly inhibited the OMOR, suggesting strong adsorption on Pt(111) domains.
Conclusions:
- Pt(111) exhibits distinct oscillatory methanol electrooxidation behavior compared to polycrystalline Pt.
- Surface intermediate accumulation influences OMOR dynamics and leads to potential drift.
- Sulfate adsorption plays a critical role in inhibiting OMOR on Pt(111) by blocking active sites.
Related Concept Videos
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
11.1K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
11.1K
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
3.4K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
3.4K
02:45E2 Reaction: Kinetics and Mechanism
10.9K
SN2 substitutions and E2 eliminations of alkyl halides proceed via a concerted pathway. While the nucleophile attacks the alpha carbon in SN2 reactions, it functions as a strong base and abstracts a beta hydrogen in the E2 mechanism. The rate-limiting transition state in E2 elimination reactions is characterized by partially broken carbon–hydrogen and carbon–halogen bonds and a partially formed pi bond between the alpha and beta carbons. The beta hydrogen and halide are eliminated...
10.9K
01:17Thermal Electrocyclic Reactions: Stereochemistry
2.2K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.2K
02:21Oxidation of Alkenes: Syn Dihydroxylation with Potassium Permanganate
13.8K
Alkenes can be dihydroxylated using potassium permanganate. The method encompasses the reaction of an alkene with a cold, dilute solution of potassium permanganate under basic conditions to form a cis-diol along with a brown precipitate of manganese dioxide.
13.8K
01:46Oxidative Cleavage of Alkenes: Ozonolysis
11.4K
In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
11.4K