Selective Electro-Oxidation of Glycerol to Glycolate On Au/CNT Catalysts

Selective Electro-Oxidation of Glycerol to Glycolate on Au/CNT Catalysts

Zhiyong Zhang, Le Xin, Ji Qi, Zhichao Wang, Li Wenzhen

Glycolic acid has a broad range of cleanser applications due to its high acidity (pK_a=3.83) and chelation properties with metal ions. However, the current industry glycolic acid production processes involve formaldehyde, carbon monoxide, or hydrogen cyanide, all of them are highly toxic chemicals. In this work, we developed an alternative green approach to produce glycolate with high selectivity through electro-oxidizing bio-renewable glycerol in alkaline solution on carbon nanotube (CNT) supported gold catalyst (average particle size: 2.5 nm; 1.0 - 4.5 nm). CNT was used as electro-catalyst support based on the consideration of its higher electric conductivity, and better durability under high potentials. It has been demonstrated that the product distribution from glycerol electro-oxidation is strongly dependent on the applied anode potential. Under an anode applied potential of 1.6 V (vs. Standard Hydrogen Electrode, SHE) at ambient conditions (room temperature and atmosphere), a selectivity of 85% to glycolate was successfully achieved with a glycerol conversion of 50%, after 3 hour's reaction. The detailed reaction pathways will be presented.