Researchers at the Korea Institute of Energy Research have reported a carbon‑monoxide‑driven process that forms metal thin films about 0.3 nm thick, enabling faster fabrication of core‑shell fuel‑cell catalysts that reduce platinum usage while maintaining performance. The approach, called CO Adsorption‑Induced Deposition (CO AID), leverages the redox behavior and strong surface affinity of carbon monoxide to deposit atomically controlled platinum shells on low‑cost metal cores without additional reducing agents or electrochemical systems.

Core‑shell catalysts place a thin platinum shell over a different‑metal core to achieve high oxygen‑reduction‑reaction (ORR) activity with less platinum, improving fuel‑cell economics. The new process adsorbs a single molecular layer of CO on the core surface and then selectively reduces platinum onto that layer, controlling shell thickness at approximately 0.3 nm.

Key advantages of CO AID include:

• Speed: Processing time is reduced to 30 minutes – 2 hours at kilogram scale, compared with more than 24 hours for conventional copper under‑potential deposition routes that require tight voltage control and oxide‑removal steps.

• Simplicity: By avoiding those steps, CO AID simplifies production while retaining the atomic‑layer precision needed for high‑performance shells.

Using CO AID, the team coated platinum onto palladium, gold, and iridium cores. A palladium‑based platinum core‑shell catalyst achieved about double the ORR activity and 1.5 × the durability compared with commercial platinum‑on‑carbon benchmarks. The work was conducted in collaboration with Brookhaven National Laboratory and was published on Nov 7, 2025 in ACS Nano, with support from the Ministry of Science and ICT.

“This work originated from the idea of converting carbon monoxide’s toxicity into a tool for nanoscale thin‑film control. By allowing materials to be precisely engineered at the atomic level and drastically reducing processing time, the technology presents a new synthesis paradigm with excellent prospects for commercialization,” said lead researcher Gu‑Gon Park.

“Being able to manipulate the surfaces of metal nanoparticles at the atomic‑layer scale using something as simple as carbon monoxide means this technology could have far‑reaching implications—not only for fuel‑cell catalyst production, but also for advancing nanoparticle manufacturing in areas such as semiconductors and thin‑film materials,” added team member Yongmin Kwon.

Research Report: CO Adsorption‑Induced Deposition: A Facile and Precise Synthesis Route for Core‑Shell Catalysts (ACS Nano, 2025).