Electrocatalytic activity and stability of carbon nanotubes-supported Pt-on-Au, Pd-on-Au, Pt-on-Pd-on-Au, Pt-on-Pd, and Pd-on-Pt catalysts for methanol oxidation reaction

• Compared with Pd-on-Au catalyst, Pt-on-Au catalyst exhibits higher activity for methanol oxidation in alkaline media but lower stability.
• After modifying Pd surface with low amount of Pt, the activity for methanol oxidation get improved greatly.
• The Pt deposited on Pd shows improved stability in comparison with the Pt deposited on Au substrate.
• The total mass activity of Pt-on-Pd/CNTs for methanol oxidation is on a similar level to that of Pt/CNTs.

For optimizing both the activity and stability of Pt-based catalysts for methanol oxidation reaction (MOR), several carbon nanotubes(CNTs)-supported catalysts such as Pt-on-Au/CNTs, Pd-on-Au/CNTs, Pt-on-Pd-on-Au/CNTs, Pt-on-Pd/CNTs, and Pd-on-Pt/CNTs catalysts are synthesized mainly through electrodeposition method. The activity and stability comparisons show that Pt-on-Au/CNTs has a higher MOR activity but a lower stability than Pd-on-Au/CNTs. To utilize the merits of the Pt and Pd components, Pt-on-Pd-on-Au/CNTs and Pt-on-Pd/CNTs catalysts are synthesized. The Pt-on-Pd-on-Au/CNTs and Pt-on-Pd/CNTs catalysts shows higher MOR activity than Pd-on-Au/CNTs and Pd/CNTs catalysts and higher stability than Pt-on-Au/CNTs, suggesting a synergistic interaction between Pt and Pd in catalyzing methanol oxidation reaction. Calculation shows that the total mass activity of Pt-on-Pd/CNTs with quite low Pt amount is on a similar level as that of Pt/CNTs for MOR oxidation, indicating the Pt-on-Pd catalyst could have promising potential as a low-Pt catalyst for MOR in alkaline media.

By modifying Pd surface with Pt moieties, both the methanol oxidation activity and cycling stability get evidently improved.Figure optionsDownload as PowerPoint slide