In situ TEM observation of oxygen evolution reaction in GDC-Pt half cell at elevated temperatures

TL;DR

This study uses in situ TEM techniques to observe the oxygen evolution reaction at GDC-Pt interfaces in solid oxide fuel cells at high temperatures, revealing ionic activity and oxidation state changes.

Contribution

It introduces in situ electron holography and EELS to directly observe ionic activity and oxidation states during the oxygen evolution reaction in GDC-Pt systems.

Findings

Ionic activity occurs at GDC-Pt interfaces at elevated temperatures.

Gadolinium exhibits a new oxidation state during the reaction.

Doped cations are active in the oxygen evolution process.

Abstract

Gadolinium-doped ceria was studied in a half SOFCs at elevated temperatures. In situ electron holography could reveal ionic activity in a single GDC-Pt interface at the elevated temperatures that result in further oxidation of the GDC. In situ EELS measurements confirmed holography results and showed the existence of the gadolinium in a new oxidation state. Also, it was found that the doped cations are the active ions in the oxygen evolution reaction from the solid oxide electrolyte.