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Synthesis of Platinum-nickel Nanowires and Optimization for Oxygen Reduction Performance
Published on: April 27, 2018
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Enhanced oxygen reduction reaction on caffeine-modified platinum single-crystal electrodes
Nagahiro Hoshi1, Masashi Nakamura2, Ryuta Kubo2
1Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Chiba University, 1-33 Yayoi-cho Inage-ku, Chiba, 263-8522, Japan. hoshi@faculty.chiba-u.jp.
Communications Chemistry
|February 3, 2024
Summary
Caffeine significantly boosts oxygen reduction reaction (ORR) activity in fuel cells by reducing blocking species on platinum surfaces. This enhancement varies by platinum crystal face, offering new avenues for catalyst design.
Area of Science:
- Electrochemistry
- Materials Science
- Catalysis
Background:
- The oxygen reduction reaction (ORR) is vital for efficient fuel cell operation.
- Hydrophobic species are known to positively influence ORR activity.
- Understanding catalyst surface interactions is key to improving fuel cell performance.
Purpose of the Study:
- To investigate the effect of caffeine on the oxygen reduction reaction (ORR) activity on different platinum (Pt) surfaces.
- To elucidate the mechanism by which caffeine influences ORR activity.
- To explore caffeine as a potential promoter for ORR catalysts.
Main Methods:
- Electrochemical measurements were performed in a 0.1 M HClO4 aqueous solution.
- The ORR activity of Pt(111), Pt(110), and Pt(100) surfaces with and without caffeine was evaluated.
- Infrared (IR) spectroscopy was used to analyze surface species, specifically PtOH.
- Caffeine adsorption geometry on different Pt surfaces was studied.
Main Results:
- Caffeine enhanced the specific ORR activity of Pt(111) by 11-fold and Pt(110) by 2.5-fold.
- The ORR activity of Pt(100) remained unaffected by caffeine.
- A decrease in the infrared (IR) band of PtOH, a known ORR blocking species, was observed on all surfaces.
- Caffeine adsorption geometry varied: perpendicular on Pt(111) and Pt(110), tilted on Pt(100).
Conclusions:
- Caffeine acts as an effective promoter for ORR on specific platinum surfaces (Pt(111) and Pt(110)).
- The enhancement in ORR activity is attributed to the reduction of PtOH coverage.
- Adsorption geometry of caffeine plays a critical role in its effect on ORR activity.
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