Mass‐Spectrometric Imaging of Electrode Surfaces—a View on Electrochemical Side Reactions. (2nd September 2020)

• Record Type: Journal Article
• Authors: Fangmeyer, Jens; Behrens, Arne; Gleede, Barbara; Waldvogel, Siegfried R.; Karst, Uwe
• Is Part Of: Angewandte Chemie. Volume 132:Number 46(2020)
• Page Start: 20608
• Page End: 20613
• Publication Date: 2020-09-02
• Subjects: electrochemical side reactions -- electrochemistry -- electrode fouling -- MALDI-MS imaging -- polymerization; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202010134
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Electrochemical side reactions, often referred to as "electrode fouling", are known to be a major challenge in electro‐organic synthesis and the functionality of modern batteries. Often, polymerization of one or more components is observed. When reaching their limit of solubility, those polymers tend to adsorb on the surface of the electrode, resulting in a passivation of the respective electrode area, which may impact electrochemical performance. Here, matrix‐assisted laser‐desorption/ionization mass spectrometry (MALDI‐MS) is presented as valuable imaging technique to visualize polymer deposition on electrode surfaces. Oligomer size distribution and its dependency on the contact time were imaged on a boron‐doped diamond (BDD) anode of an electrochemical flow‐through cell. The approach allows to detect weak spots, where electrode fouling may take place and provides insight into the identity of side‐product pathways. Abstract : In‐depth understanding of electrochemical side reactions is essential for the optimization of new electrode materials or electrochemical cell geometry. The presented MALDI‐MS imaging approach offers a fast and elegant way to detect electrochemical byproducts on the electrode surface and provides additional information about molecular mass and spatial distribution.