Highly Dispersed Ni over a YSZ Anode Anchored by SiO_2 at High Temperature through Low-Temperature Chemical Vapor Deposition

摘要

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 ℃ and reductive hydrothermal environments. In this study, Ni particles are successfully dispersed on YSZ through strong interaction between Ni and SiO_2. The thin and amorphous SiO_2 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 ℃. Also, the SiO_2-anchored Ni particles supported on YSZ (Ni/YSZ-SiO_2) are obtained via direct reduction. The electrochemical performance of the Ni/YSZ-SiO_2 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 SiO_2-anchored Ni particles exhibits high stability under testing and reductive hydrothermal conditions. Accordingly, the method of growing a SiO_2 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.