This study addresses the critical challenge of carbon corrosion in proton exchange membrane fuel cells (PEMFCs) by developing hybrid supports that combine the high surface area of carbon black (CB) with the superior crystallinity and graphitic structure of carbon nanofibers (CNFs). Two commercially available CB samples were physically activated and composited with two types of CNFs synthesized via chemical vapor deposition using different carbon sources. The structure, morphology, and crystallinity of the resulting CNF–CB hybrid supports were characterized, and the performances of these hybrid supports in mitigating carbon corrosion and enhancing the PEMFC performance was evaluated through full-cell testing in collaboration with a membrane electrode assembly (MEA) manufacturer (VinaTech, Seoul, Republic, of Korea), adhering to industry-standard fabrication and evaluation procedures. Accelerated stress tests following the US Department of Energy protocols revealed that incorporating CNFs enhanced the durability of the CB-based hybrid supports without compromising their performance. The improved performance of the MEAs with the hybrid carbon support is attributed to the ability of the CNF to act as a structural backbone, facilitate water removal, and provide abundant edge plane sites for anchoring the platinum catalyst, which promoted the oxygen reduction reaction and improved catalyst utilization. The findings of this study highlight the potential of CNF-reinforced CB supports for enhancing the durability and performance of PEMFCs.

Uniform thin tubular carbon nanofibers (TCNFs), composed of two nanofibrils ca. 20 nm in diameter and with relatively high graphitic property, were prepared using a chemical deposition method from a CO/H₂ gas mix (1:4 v/v) over a novel bimetallic (Fe–Mn, 3:7 w/w) catalyst at a low temperature of 500–540 °C. Mn effectively activated the Fe catalyst when preparing selective thin TCNFs. The specific amount of Mn 70 wt % on the Fe–Mn catalyst was key for the selective preparation of uniform duplicated CNFs with an aligned tubular graphene structure. The obtained TCNFs had relatively high graphitic property; the interlayer spacing (d ₀₀₂) and the stacking height Lc(002) were 5.4 nm, respectively, because of the unique duplicated morphology.