Highly Dispersed Ni over a YSZ Anode Anchored by SiO2 at High Temperature through Low-Temperature Chemical Vapor Deposition

Abstract

Supported Ni on yttria stabilized zirconia (YSZ) is the most widely used anode for a solid oxide fuel cell (SOFC), where Ni particles are easy to agglomerate at a high temperature of 1400 °C and reductive hydrothermal environments. In this study, Ni particles are successfully dispersed on YSZ through strong interaction between Ni and SiO2. The thin and amorphous SiO2 films, grown by low-temperature chemical vapor deposition (CVD), become spherical particles of nickel silicates uniformly dispersed on the YSZ skeleton after sintering at 1400 °C. Also, the SiO2-anchored Ni particles supported on YSZ (Ni/YSZ-SiO2) are obtained via direct reduction. The electrochemical performance of the Ni/YSZ-SiO2 anode shows a higher power density of approximately 18% than an unmodified Ni/YSZ anode, which resulted from the longer effective TPB area assigned to the highly dispersed Ni particles. The microstructure containing SiO2-anchored Ni particles exhibits high stability under testing and reductive hydrothermal conditions. Accordingly, the method of growing a SiO2 layer via low-temperature CVD is considered as a probable route for the preparation of the Ni/YSZ electrode material with a well-defined microstructure.