Heusler alloy catalysts for electrochemical CO₂ reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical CO2 reduction reaction (ECO2RR) to hydrocarbons is crucial for sustainable energy but faces challenges with catalyst efficiency, high overpotential, and poor selectivity.
• Heusler alloys are a class of materials with tunable properties, but their potential for ECO2RR has not been explored.

Purpose of the Study:

• To investigate Heusler alloys as novel catalysts for ECO2RR using density functional theory.
• To identify specific Heusler alloy compositions with high activity and selectivity for hydrocarbon production from CO2.

Main Methods:

• Density functional theory (DFT) calculations were employed to study the catalytic performance of various Heusler alloys (Cu2TMAl).
• The study analyzed the adsorption energies of key intermediates (CHO, COOH, CO) and the competition with the hydrogen evolution reaction.

Main Results:

• The linear scaling relationship between intermediate adsorption energies was broken in Heusler alloys, enabling tunable overpotentials.
• Cu2ZnAl exhibited the highest activity and selectivity for ECO2RR among 30 investigated alloys, showing a 41% energy efficiency improvement over pure Cu.
• Cu2PdAl, Cu2AgAl, Cu2PtAl, and Cu2AuAl were also identified as promising candidates.

Conclusions:

• Heusler alloys, particularly Cu2ZnAl, are viable and efficient catalysts for electrochemical CO2 reduction to hydrocarbons.
• This research opens up a broad area for exploring numerous other Heusler alloys for advanced CO2 conversion technologies.