National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People's Republic of China.
J Synchrotron Radiat. 2023 Mar 1;30(Pt 2):340-346. doi: 10.1107/S1600577523000796. Epub 2023 Feb 16.
Monitoring the surface dynamics of catalysts under working conditions is important for a deep understanding of the underlying electrochemical mechanisms towards efficient energy conversion and storage. Fourier transform infrared (FTIR) spectroscopy with high surface sensitivity has been considered as a powerful tool for detecting surface adsorbates, but it faces a great challenge when being adopted in surface dynamics investigations during electrocatalysis due to the complication and influence of aqueous environments. This work reports a well designed FTIR cell with tunable micrometre-scale water film over the surface of working electrodes and dual electrolyte/gas channels for in situ synchrotron FTIR tests. By coupling with a facile single-reflection infrared mode, a general in situ synchrotron radiation FTIR (SR-FTIR) spectroscopic method is developed for tracking the surface dynamics of catalysts during the electrocatalytic process. As an example, in situ formed key *OOH is clearly observed on the surface of commercial benchmark IrO catalysts during the electrochemical oxygen evolution process based on the developed in situ SR-FTIR spectroscopic method, which demonstrates its universality and feasibility in surface dynamics studies of electrocatalysts under working conditions.
在工作条件下监测催化剂的表面动力学对于深入了解高效能量转换和存储的基础电化学机制非常重要。傅里叶变换红外（FTIR）光谱具有高表面灵敏度，被认为是检测表面吸附物的有力工具，但由于水相环境的复杂性和影响，在电催化过程中的表面动力学研究中采用 FTIR 光谱面临着巨大的挑战。本工作报道了一种设计精良的 FTIR 池，其在工作电极表面具有可调谐的微尺度水膜和双电解质/气体通道，用于同步辐射 FTIR 的原位测试。通过耦合简单的单次反射红外模式，开发了一种通用的原位同步辐射 FTIR（SR-FTIR）光谱方法，用于跟踪电催化过程中催化剂的表面动力学。例如，基于开发的原位 SR-FTIR 光谱方法，在电化学析氧过程中清楚地观察到商用基准 IrO 催化剂表面原位形成的关键*OOH，这证明了它在工作条件下电催化剂表面动力学研究中的通用性和可行性。
