Electrochemistry Laboratory , Paul Scherrer Institut , Forschungsstrasse 111 , 5232 Villigen PSI , Switzerland.
Laboratory of Physical Chemistry , ETH Zürich , 8093 Zürich , Switzerland.
ACS Appl Mater Interfaces. 2019 Sep 25;11(38):34787-34795. doi: 10.1021/acsami.9b04456. Epub 2019 Sep 13.
Co/Fe oxyhydroxide catalysts have been deposited onto the surface of amorphous carbons or different perovskite oxides. By performing electrochemical characterizations and operando X-ray absorption spectroscopy measurements, novel insights into Co/Fe oxyhydroxide catalysts and their interactions with perovskite oxides have been revealed. The addition of Fe into Co oxyhydroxide catalysts greatly enhances the oxygen evolution reaction (OER) activity by stabilizing the Co cations into a lower oxidation state under operative conditions compared to the case of undoped Co oxyhydroxide. A beneficial Co/Fe electronic interaction for OER can also be achieved by depositing Co oxyhydroxide on Fe-containing oxide supports, such as the LaFeO perovskite. Finally, it was found that, despite the lower Fe content in the BaSrCoFeO (BSCF) perovskite structure, Co oxyhydroxides supported on this perovskite exhibit the highest OER activity. Therefore, our findings suggest that perovskite structures presenting a large content of oxygen vacancies and undergoing surface reconstruction, such as BSCF, offer the best interface for Co oxyhydroxides. Finally, profiting from the beneficial Co/Fe electronic interaction and perovskite interface interaction, the highest OER activity has been achieved by depositing Co/Fe oxyhydroxide on the surface of BSCF perovskite.
钴/铁氢氧化物催化剂已沉积在非晶态碳或不同钙钛矿氧化物的表面上。通过电化学特性和原位 X 射线吸收光谱测量，揭示了钴/铁氢氧化物催化剂及其与钙钛矿氧化物相互作用的新见解。与未掺杂的钴氢氧化物相比，将铁添加到钴氢氧化物催化剂中可以通过在操作条件下将钴阳离子稳定在较低的氧化态来极大地提高氧析出反应（OER）活性。通过将钴氢氧化物沉积在含铁氧化物载体上，例如 LaFeO 钙钛矿，也可以实现有利于 OER 的 Co/Fe 电子相互作用。最后，发现尽管 BaSrCoFeO（BSCF）钙钛矿结构中的铁含量较低，但负载在该钙钛矿上的钴氢氧化物表现出最高的 OER 活性。因此，我们的研究结果表明，具有大量氧空位并经历表面重构的钙钛矿结构，如 BSCF，为钴氢氧化物提供了最佳的界面。最后，通过在 BSCF 钙钛矿表面沉积 Co/Fe 氢氧化物，利用有利的 Co/Fe 电子相互作用和钙钛矿界面相互作用，实现了最高的 OER 活性。
