Unlike secondary batteries that need to be recharged, fuel cells are a type of eco-friendly power generation system that produce electricity directly from electrochemical reactions using hydrogen as fuel and oxygen as oxidant. There are various types of fuel cells, differing in operating temperatures and electrolyte materials. Solid oxide fuel cells (SOFCs), which use a ceramic electrolyte, are receiving increasing attention. Because they operate at high temperatures around 700 degrees Celsius, they offer the highest efficiency among fuel cell types, and can also be used to produce hydrogen by steam decomposition. For the commercialization of this technology, further improvement of cell performance is necessary, and novel high-temperature catalyst materials are highly anticipated.