A novel synthetic process was developed to synthesize nano-sized core-shell catalysts through atomic rearrangement by heat-treatment. Agglomeration of nanoparticles caused by the high-temperature heat-treatment was alleviated by using a modified protective coating method. In this method, the carbon layer formed by the carbonization of polydopamine serves as a protective coating layer, which suppresses the sintering of the catalyst particles continuously until the high-temperature heat-treatment is completed. Later, the carbonized carbon layer is removed by ozone treatment because it blocks the active site of the catalyst. Since ozone is a highly oxidative gas, it can selectively remove the carbon layer at room temperature in just 7 minutes without affecting the physical properties of the catalyst itself, which makes this method suitable for mass production. The Pt-based alloy catalyst was prepared by this unique process was proved to have a Pt-rich shell structure, and the particles can remain small (∼5 nm) even after high-temperature heat-treatment, thus exhibiting high oxygen reduction reaction (ORR) activity in fuel cells.
Bibliographical noteFunding Information:
This material is based upon work supported by the Ministry of Trade, Industry & Energy (MOTIE, Korea) under Industrial Technology Innovation Program No. 10062511 and the Human Resources Program in Energy Technology of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20174010201640).
© 2018 The Electrochemical Society.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry