Development of non-noble Co–N–C electrocatalyst for high-temperature proton exchange membrane fuel cells

Abstract The development of a non-noble Co–N/MWCNT (MWCNT = multi-walled carbon nanotubes) electrocatalyst is achieved through the high-temperature pyrolysis method and successfully characterized by five-step physico-chemical analysis. By utilizing high-resolution analytical surface characterization methods, the chemical states of elements are determined, and the presence of Co-Nx sites is confirmed. ORR activity of a Co–N/MWCNT is found to be auspicious. The maximum number of transferred-electron (n) and the diffusion-limiting current density (jd) are calculated as 3.95 and 4.53 mA· cm−2, respectively. The catalyst is further evaluated under a single-cell test station. The test results show that the current and power density values of Co–N/MWCNT are found superior to those of the commercial Pt/C at the 150 °C and 160 °C (e.g., 57 vs. 69 mW· cm−2 at 150 °C). Due to some stability issues, it is observed that the performance of the Co–N/MWCNT catalyst is slightly decreased while switching the temperature towards 180 °C.