Investigation of Localized Catalytic and Electrocatalytic Processes and Corrosion Reactions with Scanning Electrochemical Microscopy (SECM)

Abstract

Scanning Electrochemical Microscopy (SECM) . Catalytic Electrodes .Electrochemical Energy Conversion . Fuel Cells . Oxygen Reduction Reaction . CorrosionScanning electrochemical microscopy (SECM) has developed into a very versatile tool for the investigation of solid-liquid, liquid-liquid and liquid-gas interfaces. The arrangement of an ultramicroelectrode (UME) in close proximity to the interface under study allows the application of a large variety of different experimental schemes. The most important have been named feedback mode, generation-collection mode, redox competition mode and direct mode. Quantitative descriptions are available for the UME signal, depending on different sample properties and experimental variables. Therefore, SECM has been established as an indispensible tool in many areas of fundamental electrochemical research. Currently, it also spreads as an important new method to solve more applied problems, in which inhomogeneous current distributions are typically observed on different length scales. Prominent examples include devices for electrochemical energy conversion such as fuel cells and batteries as well as localized corrosion phenomena. However, the direct local investigation of such systems is often impossible. Instead, suitable reaction schemes, sample environments, model samples and even new operation modes have to be introduced in order to obtain results that are relevant to the practical application. This review outlines and compares the theoretical basis of the different SECM working modes and reviews the application in the area of electrochemical energy conversion and localized

Fountain pen for scanning electrochemical microscopy

“…7,18-21 Therefore, SECM has been successfully applied to the screening of catalysts, 22 to the study of corrosion 23 and biological processes 24,25 and to surface patterning.…”

In Situ Scanning Electrochemical Microscopy (SECM) Detection of Metal Dissolution during Zinc Corrosion by Means of Mercury Sphere‐Cap Microelectrode Tips

“…The zinc sample was kept unbiased throughout the experiments. Figure 2 contrasts typical approach curves recorded either on the insulating material that surrounded the zinc surface or that performed at the sample surface by setting the tip potential at À0.70 V versus Ag/AgCl/KCl sat , where only the reduction of oxygen occurred through Equation (1). Above the insulating substrate, negative feedback is observed, which reflects the decrease in the normalized current with the decrease of the tip-substrate distance due to the partial blockage of oxygen diffusion to the microelectrode.…”

“…[1][2][3] SECM is a scanning probe microscopy (SPM) technique that is based on the amperometric signal generated at a microelectrode by redox-active species in solution, which can perform quantitative local electrochemical experiments at interfaces to gather information on the topography or reactivity of substrates. This is often achieved by applying a variety of electrochemical waveforms at the probe or at the substrate, or even by coupling SECM with other SPM techniques, particularly atomic force microscopy (AFM).…”

Scanning Electrochemical Microscopy as a Characterization Tool for Reduced Graphene Oxide Field Effect Transistors

“…Furthermore, several applications in different research fields such as metals corrosion studies [13,14], materials science [15], energy storage [16] or biological systems [17,18] use the SECM as an established system. The advantage of the constant distance mode, used in this work, is the decoupling of the electrochemical activity information from the topography [19,21].…”