Pyrolysis of Iron-Containing Polyanilines under Micropore Generation Control: Electrocatalytic Performance in the Oxygen Reduction Reaction

Quang-Duy Dao; Yuhi Inada; Masato Daijo; Hitoshi Haneoka; Yosuke Murakami; Nao Eguchi; Toru Amaya; Takeyuki Suzuki; Takafumi Ohkawa; Ryotaro Tsuji; Toshikazu Hirao

doi:10.1002/cplu.202000363

Pyrolysis of Iron-Containing Polyanilines under Micropore Generation Control: Electrocatalytic Performance in the Oxygen Reduction Reaction

Chempluschem. 2020 Sep;85(9):1964-1967. doi: 10.1002/cplu.202000363. Epub 2020 Jun 18.

Authors

Quang-Duy Dao^{1

2}, Yuhi Inada^{3

4}, Masato Daijo⁵, Hitoshi Haneoka⁴, Yosuke Murakami⁴, Nao Eguchi⁶, Toru Amaya⁷, Takeyuki Suzuki⁴, Takafumi Ohkawa⁵, Ryotaro Tsuji⁸, Toshikazu Hirao⁴

Affiliations

¹ Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan.
² Present address: Faculty of Physics, VNU-University of Science Vietnam National University, Hanoi, Thanhxuan, Hanoi, 120-034, Vietnam.
³ Kyoto Institute of Technology, Matsugasaki, Kyoto, 606-8585, Japan.
⁴ The Institute of Scientific and Industrial Research, Osaka University, Mihoga-oka, Ibaraki, Osaka, 567-0047, Japan.
⁵ Osaka R&D Laboratory Daihachi Chemical Industry Co.,LTD., 3-5-7 Chodo, Higashiosaka, Osaka, 577-0056, Japan.
⁶ Center for Scientific Instrument Renovation and Manufacturing Support, Osaka University, Mihoga-oka, Ibaraki, Osaka, 567-0047, Japan.
⁷ Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Yamada-oka, Suita, Osaka, 565-0871, Japan.
⁸ KANEKA Fundamental Technology Research Alliance Laboratories, Graduate School of Engineering, Osaka University, Yamada-oka, Suita, Osaka, 565-0871, Japan.

PMID: 32558270
DOI: 10.1002/cplu.202000363

Abstract

Pyrolyzed iron-containing polyaniline (C-Fe-PANI) is one of the most promising candidates as a non-precious metal based electrocatalyst for oxygen reduction reaction (ORR). Although the ORR activity depends on the surface area arisen from pyrolysis-generated micropores on C-Fe-PANI particles, the micropore generation is hindered by pyrolysis-formed iron nanoparticles (Fe NPs) embedded inside C-Fe-PANI particles. Here, we demonstrate the pyrolysis of iron-containing PANIs under suppression of micropore-generation hindrance by blocking the Fe NPs formation. The higher-molecular-weight (MW: 100,000) PANI was dispersed in an FeCl₃ solution before pyrolysis for preventing FeCl₃ penetration inside PANI particles. As a result, as compared to the case of lower-MW (5,000) PANI, the Fe NPs formation was more suppressed inside catalyst particles to give 1.9 (1.8) times micropore volume (specific surface area), leading to a 11 % higher current density in ORR electrocatalytic performance test in acidic media.

Keywords: iron; microporous materials; nanoparticles; oxygen reduction reaction; polyaniline.

Grants and funding

Japan Science and Technology Agency