Selective furfural conversion via parallel hydrogenation–oxidation on MOF-derived CuO/RuO2/C electrocatalysts via pulsed laser

Abstract

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) in alkaline solution. CuO/RuO2/C showed a high HER activity with 127-mV overpotential and 98.4-mV/dec Tafel slope. In contrast, during FHR, CuO/C converted 14.93-mM furfural to furfuryl alcohol (FFA) in 120-min with a Faradaic efficiency (FE) of 80.12 %, demonstrating a high yield. Similarly, CuO/RuO2/C showed a high OER activity with lowest overpotential ∼346-mV; subsequently, adding 50-mM furfural reduced that to 1.536 V vs. RHE. Furthermore, during FOR, 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.