Mechanistic insights into electrocatalytic reactions provided by SERS

Abstract

In situ vibrational spectroscopy can provide molecular level mechanistic insights missing from purely electrochemical measurements. Surface enhanced Raman spectroscopy (SERS) is a particularly promising method and is employed in aqueous and non-aqueous studies of a variety of electrode reactions. Enhancement of the weak Raman signal is achieved by structuring the electrode surface or by use of SERS probes. This review article highlights the recent use of SERS to study several important electrode reactions; oxygen reduction and evolution, carbon monoxide oxidation and carbon dioxide reduction, and the electrocatalytic oxidation of small organic molecules such as formic acid. Figure 1:A schematic diagram of the study of electrochemical reaction mechanisms using SERS depicting the reactions covered in this review. The SERS substrate electrode must be structured in a manner to provide the SERS enhancement (see Figure 2) and the reactants, intermediates, and products detected must be located in the region in which the enhancement of the Raman signal is strong for effective detection.

Ir-Sn-Sb-O Electrocatalyst for Oxygen Evolution Reaction: Physicochemical Characterization and Performance in Water Electrolysis Single Cell with Solid Polymer Electrolyte

“…Accordingly, it is essential to obtain new lower-cost materials that catalyse the OER and present electrochemical, mechanical and thermal stability at the usual electrolyser operating conditions. A common practice that deserves attention and more research is the addition of supports and/or dopant elements in order to achieve low-load and stable catalysts with synergistic effects that speed up the oxygen evolution reaction [20][21][22][23][24][25]. Antimony doped tin oxide (ATO) has been used in multiple electrochemical applications, for instance, in fuel cells, batteries, gas sensors, solar cells, etc.…”

Electromagnetic Field Enhancement of Nanostructured TiN Electrodes Probed with Surface-Enhanced Raman Spectroscopy

“…Surface-enhanced Raman scattering (SERS) spectroscopy can deliver this information. This versatile technique is highly sensitive and surface-selective and, thus, has been widely employed [20], e.g., for investigation of surface reactions [21] and as a detection method in various optical sensor devices [22]. SERS spectroscopy exploits amplified electromagnetic fields provided by certain substrates, such as a plasmonic material, for enhancing Raman signals of molecules located within [23].…”

A Happy Get‐Together – Probing Electrochemical Interfaces by Non‐Linear Vibrational Spectroscopy

“…In this respect, optical spectroscopies offer some advantages. For example, surface‐enhanced Raman spectroscopy (SERS), [32] infrared reflection absorption spectroscopy (IRRAS), [33] and reflection anisotropy spectroscopy [34] yielded information from the electrode surfaces used in electrochemical oxidation of biomass for example glycerol, [35] about the Pt/Nafion interface for proton exchange membranes in fuel cells, [36] Pd‐water interface [37] and also from the solid‐electrolyte interphase in Li‐ion battery. [38] Recently, Stimulated Raman scattering has also been emerged as an useful probe for tracking transport of chemical species ‐ like ions near the electrodes in Li‐ion battery.…”