Electrochemical mass spectrometer: a precise analytical tool for electrochemical reactions

Electrochemical mass spectrometer is an advanced analytical instrument that combines electrochemical reactions with mass spectrometry analysis, widely used in various fields such as electrocatalysis, battery research, electrochemical corrosion, etc. It provides important support for the study of electrochemical reaction mechanisms by real-time monitoring of gas products and intermediates generated during the electrochemical reaction process.

1、 Working principle

The working principle of an electrochemical mass spectrometer is to combine an electrochemical reaction cell with the mass spectrometer. During the electrochemical reaction process, the gas or volatile substances produced enter the vacuum system of the mass spectrometer through a special semi permeable membrane. The mass spectrometer qualitatively and quantitatively analyzes these gas products by measuring ion currents with different mass to charge ratios (m/z). For example, DEMS (Differential Electrochemical Mass Spectrometry) technology utilizes pressure difference to rapidly draw the gas generated by electrochemical reactions into the mass spectrometry ionization chamber, achieving continuous measurement of volatile products.

2、 Technical features

（1） Real time monitoring

The ability to capture transient changes in electrochemical reaction processes with millisecond level time resolution is crucial for understanding reaction kinetics.

（2） High sensitivity

Due to the high sensitivity of mass spectrometry, even trace amounts of gas products can be detected, which is particularly important for studying side reactions and intermediates.

（3） In situ analysis

Electrochemical mass spectrometer analyzes in the same environment where the reaction occurs, avoiding errors that may be caused by sample transfer and ensuring the accuracy and representativeness of the data.

（4） Qualitative and Quantitative

Not only can it identify reaction products, but it can also calculate the Faraday efficiency of products through changes in current, achieving quantitative analysis.

3、 Application Fields

（1） Battery research

Electrochemical mass spectrometer has important applications in battery research, such as the development of lithium-ion battery electrolytes, lithium oxygen batteries, metal air batteries, etc. By monitoring the gas products generated during the battery reaction process in real-time, researchers can gain a deeper understanding of the charging and discharging mechanisms and failure mechanisms of the battery.

2） Electrocatalytic research

In the field of electrocatalysis, it can be used to study reactions such as hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and carbon dioxide reduction (CO ₂ RR). By monitoring the gas products generated during the reaction process, researchers can evaluate the performance and reaction mechanism of the catalyst.

（3） Electrochemical corrosion

It can also be used to study the electrochemical corrosion process and evaluate the corrosion resistance of materials by monitoring the gas products generated during the corrosion process.

IV. Conclusion

Electrochemical mass spectrometer plays an important role in the field of electrochemistry research due to its real-time monitoring, high sensitivity, in-situ analysis, and qualitative and quantitative analysis. It not only provides strong technical support for the study of electrochemical reaction mechanisms, but also demonstrates broad application prospects in fields such as battery development, electrocatalysis, and corrosion research.