2023 年 60 巻 1 号 p. 16-24
The realization of a carbon-neutral (decarbonized) society requires a shift to a hydrogen society that uses renewable energy on a large scale. The necessary technologies to realize a sustainable hydrogen society include water electrolysis, which produces hydrogen using renewable energy, and fuel cells, which generate electricity from hydrogen. To establish fuel cells and water electrolysis as widespread technologies, issues related to efficiency, cost, and durability must be resolved. A key component of fuel cell and water electrolysis cell systems is the membrane–electrode assembly, which is composed of several materials: catalyst, ionomer, and electrolyte membrane. Therefore, in order to achieve optimal device performance, it is necessary to develop materials in a multi-scale hierarchy from each material to the membrane–electrode assembly. This paper outlines nanostructured catalysts for fuel cells and water electrolysis, focusing on connected nanoparticle catalysts that have been systematically designed and developed considering the entire cell systems.