Enhanced Oxygen Reduction Activity of Platinum Micropore
Abstract The high overpotential of oxygen reduction reaction (ORR) prevents the wide commercialization of fuel cells and metal‐air batteries. To accelerate the reaction rate, porous electrocatalysts draw attention to obtain a higher specific surface area. However, the effect of micropores on ORR kin...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Wiley-VCH
2024-03-01
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| Series: | ChemElectroChem |
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| Online Access: | https://doi.org/10.1002/celc.202300654 |
| _version_ | 1827336749831946240 |
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| author | Kota Nakahara Dr. Atsunori Ikezawa Dr. Takeyoshi Okajima Prof. Dr. Hajime Arai |
| author_facet | Kota Nakahara Dr. Atsunori Ikezawa Dr. Takeyoshi Okajima Prof. Dr. Hajime Arai |
| author_sort | Kota Nakahara |
| collection | DOAJ |
| description | Abstract The high overpotential of oxygen reduction reaction (ORR) prevents the wide commercialization of fuel cells and metal‐air batteries. To accelerate the reaction rate, porous electrocatalysts draw attention to obtain a higher specific surface area. However, the effect of micropores on ORR kinetics has not been understood because of the non‐uniform pore sizes, length, and tortuosity of practical electrocatalysts. In this study, we evaluate ORR activity in a micropore using platinum model electrodes with arrays of cylindrical pores with a uniform pore diameter of 1.8 nm. The model electrodes having pore lengths of 45, 100, and 380 nm are fabricated, and their ORR performances are examined by electrochemical measurements and numerical simulations in 0.1 mol dm−3 KOH aqueous solution. The intrinsic ORR activity of the micropore is successfully obtained with the electrode having a pore length of 45 nm, where oxygen transport resistance in the micropore has little effect on ORR. It is found that the intrinsic ORR activity of the micropore is higher than that of a planar Pt surface. X‐ray photoelectron spectroscopy and CO stripping voltammetry indicate a downshift of the d‐band center, which can be the origin of the high intrinsic ORR activity. |
| first_indexed | 2024-03-07T18:39:44Z |
| format | Article |
| id | doaj.art-c824dae633754134837f2eeb19833a17 |
| institution | Directory Open Access Journal |
| issn | 2196-0216 |
| language | English |
| last_indexed | 2024-03-07T18:39:44Z |
| publishDate | 2024-03-01 |
| publisher | Wiley-VCH |
| record_format | Article |
| series | ChemElectroChem |
| spelling | doaj.art-c824dae633754134837f2eeb19833a172024-03-02T04:26:51ZengWiley-VCHChemElectroChem2196-02162024-03-01115n/an/a10.1002/celc.202300654Enhanced Oxygen Reduction Activity of Platinum MicroporeKota Nakahara0Dr. Atsunori Ikezawa1Dr. Takeyoshi Okajima2Prof. Dr. Hajime Arai3Department of Chemical Science and Engineering Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku, Yokohama Kanagawa 226–8501 JapanDepartment of Chemical Science and Engineering Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku, Yokohama Kanagawa 226–8501 JapanDepartment of Chemical Science and Engineering Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku, Yokohama Kanagawa 226–8501 JapanDepartment of Chemical Science and Engineering Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku, Yokohama Kanagawa 226–8501 JapanAbstract The high overpotential of oxygen reduction reaction (ORR) prevents the wide commercialization of fuel cells and metal‐air batteries. To accelerate the reaction rate, porous electrocatalysts draw attention to obtain a higher specific surface area. However, the effect of micropores on ORR kinetics has not been understood because of the non‐uniform pore sizes, length, and tortuosity of practical electrocatalysts. In this study, we evaluate ORR activity in a micropore using platinum model electrodes with arrays of cylindrical pores with a uniform pore diameter of 1.8 nm. The model electrodes having pore lengths of 45, 100, and 380 nm are fabricated, and their ORR performances are examined by electrochemical measurements and numerical simulations in 0.1 mol dm−3 KOH aqueous solution. The intrinsic ORR activity of the micropore is successfully obtained with the electrode having a pore length of 45 nm, where oxygen transport resistance in the micropore has little effect on ORR. It is found that the intrinsic ORR activity of the micropore is higher than that of a planar Pt surface. X‐ray photoelectron spectroscopy and CO stripping voltammetry indicate a downshift of the d‐band center, which can be the origin of the high intrinsic ORR activity.https://doi.org/10.1002/celc.202300654Microporous materialMicroporeNanostructuresOxygen reduction reactionPlatinum |
| spellingShingle | Kota Nakahara Dr. Atsunori Ikezawa Dr. Takeyoshi Okajima Prof. Dr. Hajime Arai Enhanced Oxygen Reduction Activity of Platinum Micropore ChemElectroChem Microporous material Micropore Nanostructures Oxygen reduction reaction Platinum |
| title | Enhanced Oxygen Reduction Activity of Platinum Micropore |
| title_full | Enhanced Oxygen Reduction Activity of Platinum Micropore |
| title_fullStr | Enhanced Oxygen Reduction Activity of Platinum Micropore |
| title_full_unstemmed | Enhanced Oxygen Reduction Activity of Platinum Micropore |
| title_short | Enhanced Oxygen Reduction Activity of Platinum Micropore |
| title_sort | enhanced oxygen reduction activity of platinum micropore |
| topic | Microporous material Micropore Nanostructures Oxygen reduction reaction Platinum |
| url | https://doi.org/10.1002/celc.202300654 |
| work_keys_str_mv | AT kotanakahara enhancedoxygenreductionactivityofplatinummicropore AT dratsunoriikezawa enhancedoxygenreductionactivityofplatinummicropore AT drtakeyoshiokajima enhancedoxygenreductionactivityofplatinummicropore AT profdrhajimearai enhancedoxygenreductionactivityofplatinummicropore |