Lee Woong Hee, Han Man Ho, Ko Young-Jin, Min Byoung Koun, Chae Keun Hwa, Oh Hyung-Suk
Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul, 02792, Republic of Korea.
Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.
Nat Commun. 2022 Feb 1;13(1):605. doi: 10.1038/s41467-022-28260-5.
Computational calculations and experimental studies reveal that the CoOOH phase and the intermediate-spin (IS) state are the key factors for realizing efficient Co-based electrocatalysts for the oxygen evolution reaction (OER). However, according to thermodynamics, general cobalt oxide converts to the CoO phase under OER condition, retarding the OER kinetics. Herein, we demonstrate a simple and scalable strategy to fabricate electrodes with maintaining Fe-CoOOH phase and an IS state under the OER. The changes of phase and spin states were uncovered by combining in-situ/operando X-ray based absorption spectroscopy and Raman spectroscopy. Electrochemical reconstruction of chalcogenide treated Co foam affords a highly enlarged active surface that conferred excellent catalytic activity and stability in a large-scale water electrolyzer. Our findings are meaningful in that the calculated results were experimentally verified through the operando analyses. It also proposes a new strategy for electrode fabrication and confirms the importance of real active phases and spin states under a particular reaction condition.
计算计算和实验研究表明，CoOOH相和中间自旋（IS）态是实现用于析氧反应（OER）的高效钴基电催化剂的关键因素。然而，根据热力学，一般的氧化钴在OER条件下会转变为CoO相，从而阻碍OER动力学。在此，我们展示了一种简单且可扩展的策略，用于制备在OER条件下保持Fe-CoOOH相和IS态的电极。通过结合基于原位/操作X射线的吸收光谱和拉曼光谱揭示了相和自旋态的变化。硫族化物处理的泡沫钴的电化学重构提供了高度扩大的活性表面，在大规模水电解槽中赋予了优异的催化活性和稳定性。我们的发现具有重要意义，因为计算结果通过操作分析得到了实验验证。它还提出了一种新的电极制造策略，并证实了特定反应条件下真实活性相和自旋态的重要性。
