Pd₃Co₁ Alloy Nanocluster on the MWCNT Catalyst for Efficient Formic Acid Electro-Oxidation

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The direct formic acid fuel cell (DFAFC) is a promising energy conversion technology.
• Efficient electrocatalysts are crucial for improving the performance of DFAFCs, particularly for the formic acid oxidation reaction (FAOR).
• Palladium-based catalysts are effective for FAOR but suffer from CO poisoning and dissolution.

Purpose of the Study:

• To fabricate a high-performance palladium-cobalt alloy nanocluster catalyst (Pd3Co1/CNTs) for the formic acid oxidation reaction (FAOR).
• To investigate the effect of cobalt doping and deep eutectic solvents (DESs) on the catalyst's activity and stability.
• To demonstrate a new strategy for constructing advanced alloy catalysts for direct formic acid fuel cells.

Main Methods:

• Fabrication of Pd3Co1 alloy nanoclusters on multiwalled carbon nanotubes (MWCNTs) using deep eutectic solvents (DESs).
• Electrochemical characterization of the catalyst's performance in the formic acid oxidation reaction (FAOR).
• Evaluation of anti-CO poisoning and palladium dissolution resistance.

Main Results:

• The synthesized Pd3Co1/CNTs catalyst exhibited a mass activity of 2410.1 mA mgPd-1 for FAOR, outperforming Pd/CNTs and commercial Pd/C.
• The catalyst demonstrated improved anti-CO toxicity, with an onset potential of 0.36 V.
• Cobalt doping altered the electronic state of Pd, forming Pd-Co bonds, which weakened intermediate adsorption and reduced Pd dissolution.

Conclusions:

• The Pd3Co1/CNTs catalyst synthesized in DESs offers enhanced activity and stability for the formic acid oxidation reaction (FAOR).
• The improved performance is attributed to synergistic effects of Co doping and the unique nanostructure facilitated by DES.
• This study presents a viable approach for developing high-performance palladium-alloy catalysts for direct formic acid fuel cells.