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Surface fluorinated nickel-graphene nanocomposites for high-efficiency methanol electrooxidation
- Source :
- International Journal of Hydrogen Energy. 46:27138-27148
- Publication Year :
- 2021
- Publisher :
- Elsevier BV, 2021.
-
Abstract
- Transition metal electrocatalysts with high activity and long durability are desired for methanol oxidation reaction (MOR). Here, the surface fluorinated nickel-graphene nanocomposites (F–Ni–G) are synthesized via the reduction of Si–H bonds produced by silicon and ammonium fluoride in hydrothermal condition. During this process, ionic nickel-F bonds and semi-ionic C–F bonds are introduced to the catalysts as confirmed by X-ray photoelectron spectroscopy. When F–Ni–G nanocomposites are employed as MOR catalysts, the surface fluorination is contributed to the formation of nickelic, which can increase the activity and kinetics for MOR. The onset oxidation potential of F–Ni–G-2 for methanol oxidation is 53 mV lower than that of the Ni/G catalyst without fluorine. The mass activity of F–Ni–G-2 (2493.3 A g−1) is 3.90 folds than that of Ni/G (638.5 A g−1). In addition, the density functional theory calculation indicates that the modified fluorine in graphene results in the decreased reaction energy barrier from ∗CO to ∗COOH step in MOR. The strong electronegativity of F atom makes intermediates easier to attract OH− groups and repel protons, which is conductive to decrease the reaction energy barrier for MOR. Such a facile method for the fabrication of the surface fluorinated catalytic system may be extended to the preparation of other transition metal electrocatalysts.
- Subjects :
- Materials science
Renewable Energy, Sustainability and the Environment
Graphene
Energy Engineering and Power Technology
Ionic bonding
chemistry.chemical_element
Ammonium fluoride
02 engineering and technology
010402 general chemistry
021001 nanoscience & nanotechnology
Condensed Matter Physics
01 natural sciences
0104 chemical sciences
Catalysis
law.invention
Electronegativity
Nickel
chemistry.chemical_compound
Fuel Technology
Transition metal
chemistry
Chemical engineering
law
Fluorine
0210 nano-technology
Subjects
Details
- ISSN :
- 03603199
- Volume :
- 46
- Database :
- OpenAIRE
- Journal :
- International Journal of Hydrogen Energy
- Accession number :
- edsair.doi...........91d4666db2cf6f029703ee9a6ed35ba4