Solar-Powered Asymmetric C-C Coupling toward Efficient CO₂-to-C₂₊ Hydrocarbon Conversion at Ultralow Bias

Area of Science:

• Materials Science and Nanotechnology
• Electrochemistry
• Catalysis

Background:

• Electrochemical reduction of carbon dioxide (CO2) to multicarbon (C2+) hydrocarbons is crucial for sustainable fuels and chemicals.
• Limited selectivity in CO2 reduction is often due to slow C-C coupling.
• Developing efficient catalysts is key to overcoming these limitations.

Purpose of the Study:

• To synthesize and characterize novel phosphidated copper-nickel single-atom cones (Ni1PCu2) for enhanced CO2 reduction.
• To investigate the catalytic performance, selectivity, and stability of the Ni1PCu2 catalyst.
• To elucidate the reaction mechanism for selective C2+ hydrocarbon formation.

Main Methods:

• Synthesis of Cu nanowires decorated with Ni single atoms and P.
• Electrochemical characterization under solar light irradiation.
• Analysis of catalytic performance including Faradaic efficiency and production rates.
• In-situ mechanistic studies to understand the role of catalyst components.

Main Results:

• Achieved a 91% Faradaic efficiency for CO2 to C2+ hydrocarbons (C2H4 43%, C2H6 48%) under solar light at -0.3 VRHE.
• Demonstrated a stable C2+ hydrocarbon production rate of 370 μmol h-1 cm-2 for 4 days at 100 mA cm-2.
• Identified the synergistic roles of plasmonic Cu nanowires, phosphidation-induced Cu+ sites, and Ni single atoms in facilitating C-C coupling.

Conclusions:

• The Ni1PCu2 catalyst significantly enhances selectivity and efficiency in electrochemical CO2 reduction to C2+ hydrocarbons.
• The catalyst design leverages plasmonic effects, stabilized intermediates, and targeted hydrogenation for asymmetric C-C coupling.
• This work offers a promising strategy for solar-driven conversion of CO2 into valuable chemical products.