Features:

The main body of the reaction cell is integrally formed by PTFE, and the counter electrode, working electrode and reference electrode are immersed in the electrolyte vertically. The working electrodeis horizontally aligned with the radiation source and detector. The gamma-ray transmission window is only 5mm away from the front and rear, which is enough to immerse multiple working electrodes in parallel arrays. Using a dual-channel peristaltic pump, it can be connected to the reaction cell. The electrolyte enters from the lower part of the reference electrode, and leaves from the upper part of the counter electrode after passing through the working electrode area, helping to maintain the pH value during the electrochemical reaction. Ultra-low vibration, the standard iron line width is 0.28mm/s. The radioactive source, in-situ/operando cell and detector are assembled vertically, and the electrochemical workstation can be flexibly disassembled. ⁵⁷Co(Rh) high-quality single-line radioactive source with a factory activity of 50mCi. The LND proportional counter, filled with krypton, has high detection efficiency for their on Mössbauer spectrum.

Applications

This instrument can perform Mössbauer spectrum testing of Fe-based electrocatalysts in an in-situ/operando conditions. The in-situ/operando cell has the optimal design of the working electrode and Mössbauer signal detection window, which can not only satisfy the smooth progress of the electrochemical reaction, but alsominimize the impact of the electrolyte on the collection of the Mössbauer spectrum signal.

The Mössbauer spectroscopy is a technology that studies the behavior of resonant absorption of γ-rays by a specific atomic nuclei. Energy resolution is extremely high. Hyperfine interaction, phase information, valence state, coordination structure and magnetism property of Mössbauer nuclei can be obtained. The Mössbauer spectroscopy uses keV-level γ-rays with low attenuation (does not require a vacuum environment). It can be observed under high temperature, high pressure, various gas atmosphere, as well as induced by external magnetic field, microwave, ultrasound and light, etc., to observe the electronic, structural, and magnetic evolution information in real working conditions.

Using ⁵⁷Fe to prepare samples greatly improves the absorption efficiency and quality of Mössbauer spectra, and the sampling time is shortened from 24 hours to 2-3 hours (powder samples), and high-quality spectra can be obtained in 6-7 hours (in-situ/operando test samples). The fine preparation of high-efficiency multi-layer working electrodes is conducive to the acquisition of high-quality Mössbauer signals with thin sample layer on the working electrode sheet, the sample can also be firmly smeared on the working electrode sheet.

This set of in-situ/operando device is designed with an external circulation channel for the electrolyte, so that the pH of the electrolyte in the reaction cell does not change with the reaction time.In addition, the external circulation fills the electrolyte with the reaction gas until the gas is saturated, and then circulates into the reaction cell. Participating in the reaction can realize the electrocatalytic reaction involving gases such as CO₂ and O₂, and at the same time avoid the current instability caused by the direct passage of bubbles into the reaction cell.

This set of Mössbauer instruments can perform simultaneous electrochemical/Mössbauer tests, and real-time record the performance and Mössbauer spectrum of electrocatalyst. We have already cooperated with multiple laboratories to carry out electrocatalytic in-situ/operando Mössbauer spectroscopic studies, including various reactions such asoxygen evolution reaction (OER), carbon dioxide reduction reaction (CO₂RR), oxygen reduction reaction (ORR), and a variety of high-efficiency catalyst materials such as single-atom and layered double hydroxides, etc.