Related Experiment Video
Updated: May 22, 2026
08:13
Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area
Published on: February 19, 2018
First-principles study on the incipient oxidization of Nb(110)
Qing-Gao Wang1, Jia-Xiang Shang
1School of Materials Science and Engineering, Beihang University, Beijing, People's Republic of China.
Summary
Niobium (Nb) surfaces are hard to clean due to oxygen. Density functional theory calculations reveal oxygen adsorption and diffusion mechanisms, explaining Nb(110) cleaning difficulties and NbO nanostructure formation.
Area of Science:
- Surface Science and Catalysis
- Materials Science and Engineering
- Computational Chemistry and Physics
Background:
- Niobium (Nb) surfaces, particularly the Nb(110) crystal face, are known for their difficulty in cleaning, posing challenges in surface science experiments.
- Understanding the initial stages of oxidation is crucial for controlling surface properties and developing niobium-based materials and catalysts.
Purpose of the Study:
- To investigate the incipient oxidation of the Nb(110) surface using theoretical calculations.
- To elucidate the mechanisms behind the difficulty in cleaning Nb(110) surfaces and explain experimental observations of niobium oxide formation.
Main Methods:
- Density Functional Theory (DFT) calculations were employed to study oxygen (O) dissolution, on-surface adsorption, and subsurface adsorption on Nb(110) at low concentrations.
- Thermodynamic analysis was performed on oxygen/Nb(110) systems to determine the stability of niobium oxides.
Main Results:
- The highest binding energy and minimum work function for on-surface O adsorption were observed at 0.50 monolayer (ML) coverage, aligning with experimental findings.
- At 1.00 ML coverage, oxygen adatoms promote inward diffusion of O atoms, attributed to the formation of a local electric field.
- Theoretical results support experimental observations of NbO(x) oxide formation and decomposition at high temperatures (1500-2000 K) in vacuum.
Conclusions:
- The study provides a theoretical explanation for the challenges in cleaning Nb(110) surfaces by detailing oxygen adsorption and diffusion pathways.
- The thermodynamic stability of bulk NbO in vacuum is confirmed, consistent with the experimental formation of NbO nanostructures on Nb(110) surfaces.
