Accelerating Ethanol Complete Electrooxidation via Introducing Ethylene as the Precursor for the C-C Bond Splitting

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Direct ethanol fuel cells (DEFCs) are hindered by incomplete ethanol electrooxidation due to the stable C-C bond.
• Developing efficient catalysts for ethanol oxidation reaction (EOR) is crucial for advancing DEFC technology.

Purpose of the Study:

• To propose a novel ethylene-mediated pathway for 100% C1-selectivity in ethanol oxidation.
• To develop and characterize a Pt/Al2O3@TiAl catalyst with cascade active sites for enhanced EOR.

Main Methods:

• Electrochemical in situ Fourier transform infrared spectroscopy (FTIR) and differential electrochemical mass spectrometry (DEMS) were employed.
• X-ray absorption spectroscopy and density functional theory (DFT) studies were conducted.
• Catalyst performance was evaluated for activity and durability.

Main Results:

• A unique ethylene-mediated pathway for EOR with 100% C1-selectivity was identified.
• The Pt/Al2O3@TiAl catalyst demonstrated efficient ethanol dehydration and ethylene oxidation.
• Al doping in Pt nanocrystals lowered reaction barriers and eliminated poisonous species, enhancing EOR kinetics.

Conclusions:

• The Pt/Al2O3@TiAl catalyst exhibits a specific activity 7.4 times higher than commercial Pt/C.
• The catalyst shows superior long-term durability, paving the way for practical DEFC applications.