Electro-oxidation of glycerol on CoNiBi supported on carbon cloth in alkaline media

Toward the development of non-noble metal electrocatalysts for the valorization of glycerol, the effect of the addition of Bi on Co-Ni electrocatalysts supported on carbon cloth (CC) for the electro-oxidation of glycerol (EOG) was investigated. The CoNiBi/CC electrocatalysts were prepared via an electroless deposition method and characterized using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Their electrochemical activity was investigated using cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. The effect of the Bi (NO3)3 concentration in the electroless bath on the EOG performance was studied, finding that CoNiBi/CC prepared using 6 mM Bi (NO3)3 (CoNiBi_6/CC) provided higher current density and lower onset potential than other electrocatalysts. The effect of applied potentials on the formation of products was also investigated. The analysis of the liquid products using high-performance liquid chromatography showed that formic acid (FA) was obtained as the main product along with oxalic acid as a minor product. The highest rate of FA formation was 772.95 mol cm−2 h−1 at 0.7 V vs. Ag/AgCl after 2 h of reaction, and the highest selectivity for FA was 77.5% at 0.6 V vs. Ag/AgCl. Overall, the CoNiBi/CC electrocatalyst is a promising and cost-effective alternative for the electrochemical valorization of glycerol into value-added chemicals.