Construction of PdCo catalysts on Ni bowl-like micro/nano array films for efficient methanol and ethanol electrooxidation

Direct alcohol fuel cells (DAFCs) are renewable energy sources with the potential to replace fossil fuels. Investigating high-performance electrocatalysts that promote alcohol oxidation is critical. In this study, we demonstrate simple electrodeposition for the controlled synthesis of PdCo catalysts on Ni bowl-like micro/nano array films with the assistance of the monodisperse colloidal sphere template. The PdCo catalysts with the optimal properties was synthesized by optimizing the stirring rate of the electrolyte and the solution concentration. The Pd8Co1/Ni array film catalyst synthesized at a stirring speed of 200 Revolutions Per Minute (RPM) exhibited the highest electrochemical active surface area (ECSA, 95.65 cm2/mg) and specific and mass activities in methanol (173.2 mA/cm2 and 2032.9 mA/mgPd, respectively) and ethanol (240.1 mA/cm2 and 2846.1 mA/mgPd, respectively) oxidation in alkaline media. This was a considerable improvement compared to the electrocatalytic activities of single-phase Pd and a commercial Pd/C catalyst, and the superior performance of the Pd8Co1 micro/nano array film could be attributed to the bowl-like structure with a high ECSA and the synergistic effect of Pd and Co. Therefore, this study yields necessary insights into the development of high-performance electrocatalysts with potential applications in DAFCs.