The current density and catalytic properties of Cobalt-based electrocatalyts on carbon paper by sputtering for PEMFC

A Co-based MEA for polymer electrolyte membrane fuel cell were prepared by sputter deposition on 5×5cm² carbon paper and heat treatment in an NH₃ environment. There is optimum heat treatment temperature to form sufficient ligands between Co and CP, A 100nm thick Co/N/CP treated at 750°C showed more current density compared with other temperature samples. This is quite different than that of our previous report that current density is the highest at 850°C. It is related with mechanical degradation of the samples treated at 800°C or higher temperature. It can be speculated that the optimal heat temperature of Co/N/CP needed to produce maximum current density is directly related to the formation of ligands between Co and CP when linked by nitrogen. It is not possible to form sufficient ligands between Co and CP at other temperatures. That means the performance of Co-based electrocatalysts should be optimized to form sufficient ligands. It is also related with mechanical degradation.