TY - JOUR
T1 - Aqueous Electrochemical Partial Oxidation of Gaseous Ethylbenzene by a Ru-Modified Covalent Triazine Framework
AU - Kato, Shintaro
AU - Iwase, Kazuyuki
AU - Harada, Takashi
AU - Nakanishi, Shuji
AU - Kamiya, Kazuhide
N1 - Funding Information:
This research was also supported by a JSPS KAKENHI Program (Grant Nos. 17H04798 and 20H02568). This work was also supported by CREST (Grant No. JPMJCR18R3) of the Japan Science and Technology Agency (JST). Synchrotron radiation experiments were performed using the BL01B1 Beam Line of SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI; Proposal Nos. 2018A1349, 2019A1394, and 2019B1159). We thank Dr. T. Ina for providing technical support with the XAFS measurements at SPring-8.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - Aqueous electrochemical oxidation of hydrocarbons into valuable compounds, such as alcohols and carbonyl compounds, has attracted much attention because these systems can operate under mild conditions without toxic oxidants or flammable solvents. The key requirements to achieve such oxidation reactions are (1) highly reactive species on an electrocatalyst for the activation of C-H bonds and (2) efficient transportation pathway for water-insoluble hydrocarbons to an electrode surface. We have determined that a gas diffusion electrode (GDE) supporting Ru atom-modified covalent triazine frameworks (Ru-CTF) has an activity for the electrooxidation of gaseous ethylbenzene to acetophenone using an aqueous electrolyte. A high-valency Ru═O species was formed in Ru-CTF as an effective active site for O-atom insertion into stable C-H bonds. Furthermore, Ru-CTF showed excellent stability during four consecutive cycles with the replacement of the electrolyte every 12 h, although the reactive Ru═O species is generated. As for the transportation pathway for substrates, the amount of acetophenone generated from gaseous ethylbenzene was much larger than that from ethylbenzene dissolved in an electrolyte. This result indicates that the three-dimensional microstructures in the GDE maximize the transportation of gaseous hydrocarbons and the oxidation reaction occurs at the triple-phase boundary, which enables the use of aqueous electrolytes.
AB - Aqueous electrochemical oxidation of hydrocarbons into valuable compounds, such as alcohols and carbonyl compounds, has attracted much attention because these systems can operate under mild conditions without toxic oxidants or flammable solvents. The key requirements to achieve such oxidation reactions are (1) highly reactive species on an electrocatalyst for the activation of C-H bonds and (2) efficient transportation pathway for water-insoluble hydrocarbons to an electrode surface. We have determined that a gas diffusion electrode (GDE) supporting Ru atom-modified covalent triazine frameworks (Ru-CTF) has an activity for the electrooxidation of gaseous ethylbenzene to acetophenone using an aqueous electrolyte. A high-valency Ru═O species was formed in Ru-CTF as an effective active site for O-atom insertion into stable C-H bonds. Furthermore, Ru-CTF showed excellent stability during four consecutive cycles with the replacement of the electrolyte every 12 h, although the reactive Ru═O species is generated. As for the transportation pathway for substrates, the amount of acetophenone generated from gaseous ethylbenzene was much larger than that from ethylbenzene dissolved in an electrolyte. This result indicates that the three-dimensional microstructures in the GDE maximize the transportation of gaseous hydrocarbons and the oxidation reaction occurs at the triple-phase boundary, which enables the use of aqueous electrolytes.
KW - aqueous electrolyte
KW - covalent triazine frameworks
KW - gas diffusion electrode
KW - hydrocarbon oxidation
KW - ruthenium
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U2 - 10.1021/acsami.0c07228
DO - 10.1021/acsami.0c07228
M3 - Article
C2 - 32517473
AN - SCOPUS:85087932447
VL - 12
SP - 29376
EP - 29382
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 26
ER -