Electronic Structure Effect of PtCo Alloy with Adjustable Compositions for Efficient Methanol Electrooxidation

Area of Science:

• Electrochemistry
• Materials Science
• Energy Conversion

Background:

• Methanol electrooxidation in fuel cells faces challenges due to complex mechanisms and catalyst limitations.
• Developing efficient and durable anodic electrocatalysts is crucial for advancing methanol-based fuel cells.

Purpose of the Study:

• To synthesize and characterize PtCo nanoparticles supported on multiwalled carbon nanotubes (PtCo/MWCNTs) with tunable compositions.
• To evaluate the electrocatalytic performance, specifically methanol oxidation reaction (MOR) activity and durability, of the synthesized catalysts.

Main Methods:

• Synthesis of PtCo nanoparticles on MWCNTs using an adsorbing-coating-annealing-etching route.
• Electrocatalytic testing including chronoamperometry, cyclic voltammetry, and CO stripping tests.
• Compositional analysis and structural characterization of the catalysts.

Main Results:

• Pt1Co3/MWCNTs demonstrated superior MOR activity and durability compared to commercial Pt/C catalysts.
• The synthesized catalyst exhibited high electrochemical mass activity (1.04 mA μg-1 Pt) and specific activity (2.18 mA cm-2).
• Pt1Co3/MWCNTs showed a lower onset potential in CO stripping and reduced current density decay in durability tests.

Conclusions:

• The enhanced performance of Pt1Co3/MWCNTs is attributed to their ordered structure, MWCNT-nanoparticle electronic interactions, and optimal Pt/Co ratios.
• This catalyst design offers a novel approach for developing advanced methanol electrooxidation catalysts.
• The findings pave the way for the practical application of fuel cells.