Development of cathode ordered membrane electrode assembly based on TiO2 nanowire array and ultrasonic spraying

Membrane electrode assembly (MEA) is the core component of proton exchange membrane fuel cells (PEMFCs). The multi-phase channels inside the catalyst layer of the MEA are generally messy, thus leading to inefficient mass transfer characteristics. Meanwhile, the corrosion of carbon carriers and agglomeration of catalyst will aggravate the performance degradation and reduce its service life. This study presented an MEA with cathode ordered catalyst layer to improve the mass transfer characteristics and durability. The TiO2 nanowire arrays were prepared on the porous surface of carbon paper by seed-assisted hydrothermal reaction, the catalyst was applied on the surfaces of TiO2 carrier and PEM uniformly by ultrasonic spraying. The microstructure characterization and electrochemical tests were conducted, and the results showed that the peak power of the cathode ordered MEA (CO-MEA) can reach 539.5 mW/cm2 at a platinum loading of 0.21 mg/cm2. Furthermore, the MEA with ordered cathode catalyst layer can maintain a higher output voltage under high current density, indicating that the MEA's internal three-phase reaction channels have been significantly improved. Finally, by comparing with the other processes, it was found that the combination of ultrasonic spraying and cathode ordered structures would be a promising solution for developing efficient and stable MEA.