Mitraka E, Jafari M J, Vagin M, Liu X, Fahlman M, Ederth T, Berggren M, Jonsson M P, Crispin X
Department of Science and Technology , Linkoping University , Campus Norrkoping , S-60174 Norrkoping , Sweden . Email:
Department of Physics, Chemistry and Biology , Linkoping University , S-581 83 Linkoping , Sweden.
J Mater Chem A Mater. 2017 Mar 7;5(9):4404-4412. doi: 10.1039/c6ta10521a. Epub 2017 Feb 6.
The conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) has shown promise as air electrode in renewable energy technologies like metal-air batteries and fuel cells. PEDOT is based on atomic elements of high abundance and is synthesized at low temperature from solution. The mechanism of oxygen reduction reaction (ORR) over chemically polymerized PEDOT:Cl still remains controversial with eventual role of transition metal impurities. However, regardless of the mechanistic route, we here demonstrate yet another key active role of PEDOT in the ORR mechanism. Our study demonstrates the decoupling of conductivity (intrinsic property) from electrocatalysis (as an extrinsic phenomenon) yielding the evidence of doping of the polymer by oxygen during ORR. Hence, the PEDOT electrode is electrochemically reduced (undoped) in the voltage range of ORR regime, but O keeps it conducting; ensuring PEDOT to act as an electrode for the ORR. The interaction of oxygen with the polymer electrode is investigated with a battery of spectroscopic techniques.
导电聚合物聚（3,4-乙撑二氧噻吩）（PEDOT）在金属空气电池和燃料电池等可再生能源技术中作为空气电极展现出了潜力。PEDOT基于高丰度的原子元素，且由溶液在低温下合成。化学聚合的PEDOT:Cl上氧还原反应（ORR）的机制仍存在争议，过渡金属杂质的最终作用尚不明确。然而，无论其机制途径如何，我们在此证明了PEDOT在ORR机制中的另一个关键活性作用。我们的研究表明，电导率（固有特性）与电催化作用（作为一种外在现象）解耦，这为ORR过程中聚合物被氧掺杂提供了证据。因此，PEDOT电极在ORR区域的电压范围内被电化学还原（去掺杂），但氧使其保持导电；确保PEDOT作为ORR的电极。我们使用一系列光谱技术研究了氧与聚合物电极之间的相互作用。
