Abstract

Cu-based nanostructures establish efficient electrocatalytic activity/selectivity toward 

heterocyclic biomass-analog molecules, upgrading them into value-added chemicals 

and fuels. Herein, Cu-metal–organic framework-derived CuO/C and CuO/RuO2/C were 

fabricated via pulsed laser ablation and calcination, demonstrating multifunctional 

electrocatalytic performances toward hydrogen and oxygen evolution, furfural 

hydrogenation, and oxidation reactions (HER, OER, FHR, and FOR, respectively) in 

alkaline solution. CuO/RuO2/C showed a high HER activity with 108 mV overpotential 

and 98.4 mV/dec Tafel slope in 1.0-M KOH. In contrast, during FHR, Cu/O converted 

14.93-mM of furfural to furfuryl alcohol (FFA) in 120-min with a Faradaic efficiency (FE) 

of 80.12%, demonstrating a high conversion yield. This endows from the partial 

conversion of CuO/C to Cu2O/C during FHR, resulting in an enlarged active-site and 

selectivity. Similarly, CuO/RuO2/C showed a high OER activity with lowest 

overpotential ~346 mV; subsequently, adding 50-mM furfural reduced that to 306 mV. 

Furthermore, during FOR, the furfural conversion was highly favorable to achieve furoic 

acid (FA) upto 13.28-mM with a FE ~77.56% and C balance of ~77.56%. Moreover, 

CuO/C‖CuO/RuO2/C electrolyzer was fabricated to simultaneously convert furfural into 

FA and FFA, saving-energy with enhanced efficiency. Finally, in situ/operando 

electrochemical-Raman spectroscopy revealed the surface reorientation and MIII–O 

intermediate formation during HER and OER.