The research team of Shanghai Institute of Applied Physics has made important progress in the detection of XAFS in situ for electrolytic water

Electrocatalysis is an efficient way of energy conversion, which is widely used in fuel cell, lithium-ion air cell, electrolyzed water and other important energy conversion technology fields It is one of the research hotspots in the international energy field at present The key to the development of electrocatalysts is to characterize the state of materials at the molecular level in the in-situ working environment However, the quality of XAFS experimental data obtained in the complex in-situ environment (strong alkali environment, external potential, etc.) is often poor, which has become one of the important factors that affect XAFS users to publish high-level results Recently, the research team of Shanghai Institute of Applied Physics has made important progress in in-situ electrochemical XAFS detection method Using the self-developed advanced in-situ device, we observed the evolution process of "active phase" of a model catalyst under external potential The related research results were published in J am Chem SOC (DOI: 10.1021 / JACS 8b05294) The high quality data acquisition of XAFS is affected by many factors, especially the uniformity of samples in the optical path and the influence of stray light To solve this problem, researchers at bl14w1 line station have developed XAFS in-situ electrochemical experiment system, which consists of two parts: electrochemical in-situ reaction pool and XAFS signal detection, and successfully collected high-quality in-situ XAFS data Using this device, a high catalytic activity Prussian blue analogues (PBA) material has been studied in-situ The experimental results show that the PBA material with perfect cubic morphology has completely become an amorphous structure under the action of electrochemistry, and its atomic composition has also changed greatly Under the action of external potential, the valence state of metal Ni ion shows voltage dependent characteristics after deproton reaction At the same time, combined with DFT calculation, it is found that the valence state of metal Ni ion can activate some oxygen atoms of its coordination, make it become a possible active center site and participate in the reaction, thus effectively promoting the activity of oxygen evolution reaction (OER) This work provides new experimental insights for the current oer reaction mechanism More importantly, the successful development of this device can improve the service level of bl14w1 line station of Shanghai light source for users in the field of electrochemistry Su Xiaozhi, Wang Yu and Zhou Jing, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, are the co first authors of this paper, and Zhang Shuo and Li Jiong are the corresponding authors The research results are supported by the general program of NSFC and the youth innovation promotion association of Chinese Academy of Sciences.