Electrocatalytic C-C Coupled Oligomerization From Biomass Molecules Through Pd Single-Atom Interfacial Regulation

Area of Science:

• Sustainable Chemistry
• Catalysis
• Renewable Energy

Background:

• Fossil diesel presents sustainability and air quality challenges.
• Current biomass-to-biodiesel methods face issues like food-fuel competition and energy-intensive processing.
• Electrocatalytic C─C coupling followed by hydrodeoxygenation (HDO) is a promising but limited alternative.

Purpose of the Study:

• To overcome the limitation of dimer formation in electrocatalytic biomass upgrading.
• To develop a selective and efficient pathway for producing diesel blendstocks from biomass.
• To establish an electricity-driven route for controlled carbon-chain growth from biomass platforms.

Main Methods:

• Fabrication of a Palladium-Copper (Pd1Cu) single-atom alloy electrocatalyst.
• Electrocatalytic C─C coupling of biomass molecules (5-hydroxymethylfurfural).
• Subsequent hydrodeoxygenation (HDO) of biomass oligomers.
• Operando spectroscopy for mechanistic investigation.

Main Results:

• Achieved selective formation of biomass oligomers (dimers and trimers) with a trimer selectivity of 44.7%.
• Combined oligomer selectivity reached 95.0% with 93.2% Faradaic efficiency.
• Record production rate of approximately 50 g gcat−1 h−1.
• HDO conversion of oligomers yielded heteroatom-free n-dodecane and n-octadecane diesel blendstocks.

Conclusions:

• The Pd1Cu single-atom alloy catalyst effectively overcomes the bottleneck in electrocatalytic C─C coupling for biomass upgrading.
• A surface-confined ketyl-radical pathway, regulated by isolated Pd atoms, favors C─C coupling over hydrogenation.
• This work presents a viable, electricity-driven strategy for sustainable diesel production from biomass, enabling controlled carbon-chain growth.