Mesoporous PtPd Alloy - High Entropy Oxide Heterostructures for Efficient Electrocatalytic Methanol Oxidation...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Direct methanol fuel cells (DMFCs) are hindered by low catalyst activity and CO poisoning during methanol oxidation reactions (MOR).
• Commercial noble metal catalysts like Pt/C suffer from poor performance and durability issues.

Purpose of the Study:

• To develop a novel catalyst with enhanced activity and stability for MOR in DMFCs.
• To investigate the synergistic effects of high entropy oxides (HEO) and PtPd alloys in a mesoporous heterostructure.

Main Methods:

• In situ assembly of a mesoporous PtPd-HEO heterostructure from a metal-organic framework (MOF)-derived high entropy alloy (HEA).
• Electrochemical testing of the catalyst in a DMFC.
• In situ spectroscopic studies and density functional theory (DFT) simulations.

Main Results:

• The mesoporous PtPd-HEO catalyst exhibited mass activity over ten times higher than commercial Pt/C.
• DMFCs utilizing PtPd-HEO achieved a peak power density of 155 mW cm⁻² with long-term stability.
• HEO component modulated the PtPd alloy's electronic structure, improving MOR selectivity and hydroxyl species formation.

Conclusions:

• The PtPd-HEO catalyst demonstrates superior performance and durability for MOR, addressing key challenges in DMFC technology.
• Synergistic electronic tuning and porous structure contribute to the catalyst's enhanced properties.
• HEO-based mesoporous heterostructures represent a promising strategy for designing advanced catalysts for energy conversion.