| 초록 |
A rotating disk electrode (RDE) is a widely used method to characterize the electrocatalytic information including electron transfer number. Such number can be calculated from the Koutecky-Levich (K-L) equation utilizing the measured current density at different rotating rates. Basically, the flat and smooth electrode is presumed when estimated the electron transfer number. However, it is not easy to satisfy the above assumption with a common carbon-based electrocatalysts. Furthermore, “the flat and smooth surface” is a subjective standard. We characterized the electrode surface conditions to obtain more accurate data from the RDE experiment. So, we selected representative model catalysts such as a carbon black for 2e- reaction, and a Pt/C for a 4e- process, in an oxygen reduction reaction. AFM is adopted to examine surface roughness of the catalysts-coated electrode and we proposed the reasonable surface roughness factor (e.g. Ra and Rq) to determine the precise ORR selectivity. |
