Polyethyleneimine functionalized gold nanodendrites for gluconic acid electroreduction

The gluconic acid electroreduction reaction (GAER) coupled with renewable energy is a carbon-free and highly promising biomass utilization route. However, this process still suffers from low conversion efficiency and poor selectivity due to the competitive hydrogen evolution reaction. Some organic amine molecules can not only serve as surfactants to synthesize noble-metal based catalysts with special morphologies, but also can further optimize the catalytic activity of metal surfaces by modulating their electronic structure. Herein, polyethyleneimine (PEI) functionalized gold nanodendrites (PEI-Au NDs) are applied as an efficient electrocatalyst for GAER, in which the production rate and Faradaic efficiency of glucose on PEI-Au NDs reaches to 9.86 μg h −1 mg cata −1 and 15.7 % at − 0.80 V vs. RHE, respectively. The mechanism study through density functional theory calculations reveals that the adsorbed PEI molecule exhibits an electron donating-effect, which can promote the adsorption process of gluconic acid molecules on the Au(1   1   1) plane and the subsequent reduction process. This work offers a novel pathway to rational regulate the adsorption properties and electronic structures of noble metal-based electrocatalysts through chemical functionalization strategy.