Electrooxidation of Glycerol on Gold in Acidic Medium: A Combined Experimental and DFT Study
Journal article, 2018
Glycerol is a byproduct of biodiesel production and an abundant feedstock for synthesis of high-value chemicals. A promising approach for valorization of glycerol is electrooxidation on gold. In this work, we investigate electrooxidation of glycerol on gold in acidic media using cyclic voltammetry and density functional theory calculations. Experimentally, we observe activity for electrooxidation above a potential of 0.5 V vs. the reversible hydrogen electrode (RHE). A Pourbaix diagram is calculated to evaluate the surface coverage under reaction conditions, indicating that *O and *OH are not present at the measured onset potential. Computationally, we find that the onset potentials for partial dehydrogenation of glycerol to dihydroxyacetone, 2,3-dihydroxy-2-propenal and glyceraldehyde are 0.39, 0.39, and 0.60 V vs. RHE, respectively, while complete dehydrogenation to carbon monoxide requires 0.50 V vs. RHE. Our theoretical and experimental findings are in agreement and show the possibility of using gold as a catalyst for production of hydrogen and other valuable chemicals from glycerol.