Sohn, Yeonsun Kim, Dong-gun Lee, Ji Ho Lee, Sujin Hwang, In Seon Lee, Soo-Hyoung Yoo, Sung Jong Kim, Pil 2024-01-19T17:31:55Z 2024-01-19T17:31:55Z 2021-09-05 2020-06 0256-1115 https://pubs.kist.re.kr/handle/201004/118584 We demonstrate that control of the defect level on carbon materials is effective for enhancing the oxygen reduction reaction (ORR) performance of nonprecious-metal catalysts. Vapor-grown carbon nanofiber (VGCNF) with high crystallinity and high electronic conductivity was chosen as the substrate of our ORR catalysts. To induce defects on the VGCNF, it was subjected to ball-milling for various controlled times, yielding BMx-VGCNF (x represents the ball-milling time, 0-6 h). The defect level introduced on the VGCNF was effectively regulated by controlling the ball-milling time. Although the density of defect sites increased with increasing ball-milling time, the surface area was high-est in BM2-VGCNF. Nonprecious-metal ORR catalysts (BMx-Fe-VGCNF) were prepared by NH3 pyrolysis of Fe-ion-adsorbed BMx-VGCNF. The ball-milling of VGCNF was effective to introduce nitrogen onto the catalyst. In particular, the controlled ball-milling was important to generate highly active sites on the catalyst surface. Among the catalysts studied, BM2-Fe-VGCNF exhibited the best ORR performance, which was 2.5-times greater than that of BMx-Fe-VGCNF (x=4, 6). English KOREAN INSTITUTE CHEMICAL ENGINEERS PEM FUEL-CELLS HIGH-PERFORMANCE ACTIVE-SITES ELECTROCATALYSTS CATALYSTS IRON FABRICATION MECHANISM SURFACES CARBIDE Defect-controlled Fe-N-doped carbon nanofiber by ball-milling for oxygen reduction reaction Article 10.1007/s11814-020-0522-5 1 KOREAN JOURNAL OF CHEMICAL ENGINEERING, v.37, no.6, pp.938 - 945 KOREAN JOURNAL OF CHEMICAL ENGINEERING 37 6 938 945 scie scopus kci ART002587816 000538547300002 2-s2.0-85085688066 Chemistry, Multidisciplinary Engineering, Chemical Chemistry Engineering Article PEM FUEL-CELLS HIGH-PERFORMANCE ACTIVE-SITES ELECTROCATALYSTS CATALYSTS IRON FABRICATION MECHANISM SURFACES CARBIDE Fuel Cells Oxygen Reduction Reaction (ORR) Non-precious Metal Catalysts High-energy Ball-mill Vapor Grown Carbon Nano Fiber (VGCNF)