Influence of copper oxide modification of a platinum cathode on the activity of direct methanol fuel cell

To determine whether a copper oxide modified Pt cathode (PtCuOm) improves a performance of direct methanol fuel cells (DMFC), we performed structural and morphological analysis of the cathode and measured current–potential profile and impedance spectroscopy. Comparing with an unmodified Pt cathode, we found that PtCuOm prepared by rf sputtering techniques induced higher oxygen reduction reaction rate and suppressed electrocatalytic oxidation of methanol, which is the main reason of the mixed potential occurred at a cathode. Therefore, PtCuOm increased the power performance of DMFC applying both oxygen and air and electrochemical impedance spectra clearly supported the difference of the performance between unmodified and modified Pt electrodes. These results may play a role in better long-term stability of DMFC systems.