Organic interfacial engineering of gold nanowires for selective glycerol electrooxidation

The selective electrochemical conversion of glycerol into value-added products is a green and sustainable strategy for the biomass utilization. In this work, Au nanowires (Au-NW) modified with polyethyleneimine (PEI) molecule (Au-NW@PEI) is obtained by an up-bottom post-modification approach. Physical characterization, molecular dynamics simulation and density functional theory demonstrate that the loose-packed PEI monolayer firmly and uniformly distribute on the Au-NW surface due to the strong Au-N interaction. Electrochemical experiments and product analysis display that PEI modification significantly enhance the electro-activity of Au-NW for the glycerol electro-oxidation reaction (GEOR) due to the electronic effect. Meanwhile, the steric hindrance and electrostatic effect of PEI layer make the optimizing adsorption of intermediates possible. Therefore, the selectivity of C3 product glyceric acid over Au-NW@PEI is increased by nearly 20%. The work thus indicates that the rational design of metal-organic interface can effectively elevate the electro-activity and selectivity of Au nanostructures, which may have wide application in biomass development.