Abstract
We have quantitatively analyzed changes in the microstructure of double-layer hydrogen electrodes for solid oxide cells (SOCs), which consist of porous samaria-doped ceria (SDC) with highly dispersed Ni−Co nanoparticles as the catalyst layer (CL) and a thin current collecting layer of Ni‒YSZ cermet, whose durability we recently found to undergo a remarkable improvement via reversible cycling operation between steam electrolysis and fuel cell-modes. It was demonstrated by focused ion beam-scanning electron microscopy (FIB-SEM) that the Ni content in the CL was nearly fully maintained by the cycling operation, compared with a significant decrease in Ni after the electrolysis single-mode operation. The lower parts of many Ni‒Co particles were observed to be anchored tightly on the SDC support after the cycling operation, probably due to a strong interaction between Ni‒Co and SDC. Such a stabilization of the microstructure is proposed to contribute to the improved durability.
Funder
New Energy and Industrial Technology Development Organization
Publisher
The Electrochemical Society
Subject
Materials Chemistry,Electrochemistry,Surfaces, Coatings and Films,Condensed Matter Physics,Renewable Energy, Sustainability and the Environment,Electronic, Optical and Magnetic Materials