KIER Develops Fuel Cell Catalyst Production Using "Carbon Monoxide"

A domestic technology for producing fuel cell catalysts using carbon monoxide has been developed.

The Korea Institute of Energy Research (KIER) announced on the 27th that the research team led by Gugon Park, Yongmin Kwon, and Eunjik Lee from the Hydrogen Fuel Cell Laboratory has developed a method to produce "core-shell catalysts" more easily and quickly using carbon monoxide, which is harmful to humans.

(From the top left clockwise) Ikseong Lim, Postdoctoral Researcher Youngjoo Hwang, Senior Researcher Eunjik Lee, Senior Researcher Gugon Park, Senior Researcher Yongmin Kwon, Student Researcher Jiye Choi, Student Researcher Seoyeon Jung, Student Researcher Dohun Lee, Student Researcher Ahyeon Choi, Student Researcher Jungmin Han. Provided by Korea Institute of Energy Research

The core-shell structure refers to using different metals for the core and the shell of the catalyst, which determines the economic feasibility of fuel cells. Typically, the core is made of a low-cost metal, while the shell uses platinum to promote the fuel cell reaction. By utilizing the core-shell structure, it is possible to maintain performance while using only a small amount of expensive platinum, thereby increasing the economic efficiency of fuel cells.

To create a high-performance core-shell structure, the shell must be precisely coated onto the core surface at a thickness of about 0.3 micrometers. For this, the "underpotential copper deposition method (Cu-UPD)" is commonly used, where a thin layer of copper, a low-cost metal, is deposited on the core, followed by platinum deposition on top.

However, the Cu-UPD method requires extremely precise voltage control during the atomic-layer copper coating process, as well as an additional step to remove the oxide layer from the metal surface. It also requires a separate reducing agent. As a result, the mass production process is complicated and the production time becomes lengthy.

To address these issues, the research team utilized the strong adsorption capacity of carbon monoxide. By developing the "CO Adsorption-Induced Deposition (CO AID)" method, which leverages the redox reaction of carbon monoxide, the team enabled precise metal coating without the additional steps and reducing agents required by conventional methods, reducing the process time to one-tenth of the previous method.

Furthermore, by adsorbing carbon monoxide onto the core metal surface in the form of a single molecular layer and selectively reducing only platinum particles on top of this layer, the team succeeded in precisely controlling the metal thickness at the 0.3 micrometer level.

According to the research team, this technology makes it possible to synthesize core-shell catalysts in 1-kilogram batches within a minimum of 30 minutes to a maximum of 2 hours, compared to the previous process which required more than 24 hours.

In practice, using this technology, the team produced core-shell catalysts with a thin platinum layer on metals such as palladium, gold, and iridium. The palladium-based platinum core-shell catalyst demonstrated twice the oxygen reduction reaction (ORR) performance and 1.5 times the durability compared to the commercial platinum/carbon (Pt/C, currently the standard catalyst for fuel cells) catalyst.

Gugon Park stated, "This research began with the idea of transforming the harmfulness of carbon monoxide into a 'tool for nanoscale thin film control.' It presents a new synthesis paradigm that enables precise control of materials at the atomic level, and the significantly shortened process time increases the potential for commercialization."

Meanwhile, this research was published in the November issue of the international journal "ACS Nano" in the field of nanomaterials and was also selected as the inside cover.

This content was produced with the assistance of AI translation services.