Design of Metal Nanocatalysts for High-Performance Hydrogen Fuel Cells

A KAIST team presented an ideal electrode design to enhance the performance of high-temperature fuel cells. The new analytical platform with advanced nanoscale patterning method quantitatively revealed the electrochemical value of metal nanoparticles dispersed on an oxide electrode, thus leading to electrode design directions that could be used in a variety of eco-friendly energy technologies.

The team, working under Professor WooChul Jung and Professor Sang Ouk Kim in the Department of Materials Science and Engineering, provided an accurate analysis of the reactivity of oxide electrodes boosted by metal nanoparticles, in which all particles participate in the reaction. They identified how the metal catalysts activate hydrogen electro-oxidation on the ceria-based electrode surface and quantified how rapidly the reaction rate increases with proper choice of metals.

Metal nanoparticles with diameters of 10 nanometers or less have become key components in high-performance heterogeneous catalysts, primarily serving as catalytic activators. Recent experimental and theoretical findings suggest that optimization of the chemical nature at the metal and support interfaces is essential for performance improvement.

However, the high cost associated with cell fabrication and operation, as well as the poor stability of metal nanoparticles at high temperatures, have been long-standing challenges. To solve these problems, the team utilized a globally recognized metal nano-patterning technology that uses block copolymer self-assembled templates. The team succeeded in uniformly synthesizing metal particles 10 nanometers in size on the surface of oxide fuel cell electrodes. They also developed a technology to accurately analyze the catalyst characteristics of single particles at high temperatures and to maximize the performance of a fuel cell with minimal catalyst use.

The research team confirmed that platinum, a commonly used metal catalyst, could boost fuel cell performance by as much as 21 times even at an amount of 300 nanograms, which costs only about 0.015 KRW. They also identified and compared the characteristics of widely used metal catalysts other than platinum, such as palladium, gold, and cobalt, and elucidated the precise principle of catalyst performance through theoretical analysis.