Liquid cell TEM observation of enhanced activity in perovskite catalyst

Vasiliki Tileli’s group at École Polytechnique Fédérale de Lausanne (EPFL)  has used Hummingbird Scientific liquid cell TEM holder to demonstrate the excellent electrocatalytic activity of Ba0.5Sr0.5Co0.8Fe0.2O3-δ  (BSCF) perovskite in alkaline solution. The experimental method uses an immersion-type setup (beaker-type) for bulk electrochemical measurements and performs post-mortem image characterization and analyses. The work has been published in the Journal of the American Chemical Society (JACS)

In-situ cyclic voltammetry (CV) of BSCF and Pt in liquid cell TEM holder. Schematic shows the surface reconstruction with a spinel-like structure and Co/Fe oxyhydroxide. Copyright © 2020 American Chemical Society

The researchers conclude that the enhancement in the electrocatalytic activity of BSCF is because of the intrinsic formation of Co/Fe spinel-like on the surface of the material. The BSCF material was immersed in an alkaline solution in a beaker-like setup using a real reference electrode. After performing electrochemistry,  post-mortem EELS spectroscopy was performed to confirm the surface oxidation state of Co/Fe. The method demonstrated here emphasizes the need for an in-situ TEM holder with a real reference electrode for in-situ/operando analyses of the material without needing to perform post-mortem characterization.

Recently, Hummingbird Scientific launched a  bulk reference-based liquid cell electrochemistry holder. With our newest bulk electrochemistry holder, it is easy to incorporate any reference electrodes of choice by the user and record electrochemical data similar to what is observed in bulk-scale electrochemistry.

Reference: Tzu-Hsien Shen, Liam Spillane, Jan Vavra, Thi Ha My Pham, Jiayu Peng, Yang Shao-Horn, and Vasiliki Tileli. Oxygen Evolution Reaction in Ba0.5Sr0.5Co0.8Fe0.2O3-δ Aided by Intrinsic Co/Fe Spinel-Like Surface. The Journal of the American Chemical Society (2020).  Full paper

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