open access

https://hdl.handle.net/2115/94750

Cu, Fe, N‐doped Carbon Nanotubes Prepared through Silica Coating for Selective Oxygen Reduction to Water in Acidic Media

英語

2024-04-22

ChemCatChem

16(15)

e202400017

We report Cu, Fe, N-doped carbon nanotubes, (Cu,Fe)?N?CNT, as electrocatalysts for the oxygen reduction reaction (ORR) in acidic media. (Cu,Fe)?N?CNT was prepared using a silica coating method in pyrolysis to minimize the formation of carbon-coated metal oxide or carbide nanoparticles, which are known to be inactive for the H2O2 reduction. (Cu,Fe)?N?CNT shows a turnover frequency of 0.66 e? site?1 s?1 at +0.8?V vs. RHE and H2O2 yields of <1?% for the ORR with a utilization factor of active sites of 82?%. Kinetic analysis reveals that 4e? transfer rates for (Cu,Fe)?N?CNT are higher than those of a monometallic counterpart of Fe?N?CNT. In situ X-ray absorption spectroscopy enables us to determine redox potentials: E°’(FeIII/FeII)=0.65?V vs. RHE and E°’(CuII/CuI)=0.45?V for (Cu,Fe)?N?CNT, and E°’(FeIII/FeII)=0.65?V for Fe?N?CNT. These results indicate that bimetallic doping into carbon nanotubes gives the effect on kinetic parameters but not on thermodynamic ones. In other words, there is no direct electronic interactions between the Cu and Fe active sites for (Cu,Fe)-N-CNT because such interactions should modulate their redox potentials.

学術雑誌論文

Accepted Manuscript

This is the peer reviewed version of the following article: [Dr. Masaru Kato, Daiki Abe, Siqi Xie, Shun Sato, Natsuki Fujibayashi, Dr. Koki Matsumoto, Prof. Akira Onoda, Prof. Takashi Hayashi, Dr. Takaya Mitsui, Dr. Kosuke Fujiwara, Dr. Takashi Yamamoto, Prof. Yasuaki Einaga, Dr. Colin A. Tadgell, Yuta Kato, Prof. Kiyotaka Asakura, Prof. Ichizo Yagi, ChemCatChem 2024, Volume16, Issue15, e202400017], which has been published in final form at https://doi.org/10.1002/cctc.202400017. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

1867-3880

1867-3899