Furfural electroreduction in choline-glycerol deep eutectic solvent

Electroreduction of furfural, a platform chemical that can be obtained from lignocellulosic biomass and agricultural waste, was studied by coupling in-situ FTIR spectroscopy and cyclic voltammetry on gold and copper electrodes in Deep Eutectic Solvent (DES) unconventional medium. Choline-glycerol DES medium was selected by investigating with the help of NMR spectroscopy the stability of furfural in the two commonly used DES: choline chloride/urea 1:2 and glycerol 1:2. Instability of furfural in choline chloride/urea 1:2 and the presence of a specific reaction between urea and furfural was evidenced with the same technique. After that, the electrochemical stability of the glycerol DES itself was monitored by FTIR measurements in the absence and presence of furfural. The product of furfural reduction, furfuryl alcohol, was evidenced. The influence of the electrode morphology on the stability of the DES and the furfural behavior was investigated by synthesizing Au/C and Cu/C nanoparticles.