Researchers in South Korea have developed a catalyst technology that can significantly boost hydrogen production efficiency while using less platinum.
A research team led by Professor Yoon Myung-han of the Department of Materials Science and Engineering at Gwangju Institute of Science and Technology (GIST) recently developed a next-generation catalyst technology that dramatically enhances the performance of platinum catalysts, which are essential but expensive for hydrogen production, the scientific community reported Wednesday.
Platinum is generally considered the best-performing catalyst for producing hydrogen through water electrolysis. However, its high cost has meant that in most cases it is applied only as a thin coating on the electrode surface. As a result, reactions occurred only on the electrode surface, and performance degraded over time as particles clumped together or detached.
To overcome this limitation, the research team proposed a new strategy that extends the space where catalysts can operate into the electrode interior. The core technology is a conductive polymer film called PEDOT:PSS. This film has a structure that conducts electricity well and contains microscopic voids inside.
The researchers treated an extremely thin PEDOT:PSS film — approximately 60 nanometers thick, or one-thousandth the width of a human hair — with sulfuric acid. The film was engineered to be electrically conductive and to swell in water. The acid treatment removed low-conductivity components and created a "porous nanofiber structure" with fine internal pathways.
The electrode was made into a sponge-like porous structure that maintains its form in water while expanding appropriately. In this configuration, charges and ions can move freely through internal pathways, and platinum penetrates deep inside the film to settle as nanoparticles. The team also applied a "pulsed current electrodeposition" process in a platinum ion solution, enabling platinum to permeate evenly throughout the film interior for more uniform distribution.
Using the same amount of platinum, the team confirmed that the new catalyst technology expanded the electrochemically active surface area (ECSA) by more than 2.4 times compared to conventional methods. Catalytic performance per gram of platinum also improved approximately 3.2-fold.
