A Phosphorus-Doped Ag@Pd Catalyst for Enhanced CC Bond Cleavage during Ethanol Electrooxidation

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Complete ethanol oxidation (EOR) to CO₂ is crucial for high-performance direct ethanol fuel cells, transferring 12 electrons.
• However, EOR is often hindered by sluggish kinetics, low activity, and poor selectivity, particularly in C-C bond cleavage.

Purpose of the Study:

• To design and synthesize novel phosphorus-doped silver-core-and-palladium-shell (Ag@PdP) catalysts to promote EOR.
• To enhance the C-C bond cleavage selectivity of ethanol oxidation towards CO₂.

Main Methods:

• Synthesis of phosphorus-doped silver-core-and-palladium-shell (Ag@PdP) catalysts.
• Electrochemical evaluation of catalysts for EOR in alkaline media.
• Density functional theory (DFT) calculations and in situ Fourier-transform infrared spectroscopy (FTIR) for mechanistic studies.

Main Results:

• A Ag@Pd₂P_0.2 catalyst demonstrated superior performance for EOR to CO₂, exhibiting seven times higher mass activity and six times higher selectivity than Pd/C.
• DFT and in situ FTIR confirmed that high performance is due to increased OH adsorption on Pd sites and tensile strain effects favoring CH₃CO intermediate formation.
• The catalyst design promotes C-C bond cleavage into CO₂ rather than acetate formation.

Conclusions:

• The developed Ag@Pd₂P_0.2 catalyst significantly enhances the activity and selectivity of the ethanol oxidation reaction (EOR).
• This core-shell catalyst design offers a promising strategy for advancing direct alkaline ethanol fuel cell technology.
• The findings provide insights into catalyst design for efficient C-C bond cleavage in electrocatalysis.