Photoelectrocatalytic reactor for the oxidation of glycerol to dihydroxyacetone

Glycerol is the principal byproduct of biodiesel production, which has caused a market price drop to a level that makes its purification and incineration economically marginal. Upgrading glycerol to higher-value chemicals offers an attractive alternative, and dihydroxyacetone is an appealing target. It can be produced by the photoelectrocatalytic oxidation of glycerol. This thesis pursued three objectives: synthesis and characterization of porous BiVO4 photoanodes, design and assemble continuous photoelectrocatalytic reactors, and analyze the reaction products by HPLC. Nanoporous BiVO4 photoanodes were prepared on FTO by the electrodeposition technique. SEM, AFM, profilometry, XRD, and UV-Vis diffuse reflectance spectroscopy confirmed a porous morphology with an indirect band gap of 2.49 eV, consistent with literature for this synthesis route. Linear sweep voltammetry and chronoamperometry in an H-type cell showed that glycerol addition more than doubled the photocurrent and suppressed transient recombination spikes, saturating above 0.1 M glycerol, indicating charge-transport-limited kinetics. Two 3D-printed continuous reactors were designed and assembled, including a novel fractal reactor with an internal channel following a three-dimensional Hilbert curve, intended to approximate plug flow and narrow the residence time distribution to protect DHA from over-oxidation. HPLC chromatograms of the H-cell reactions revealed two dominant, growing product peaks under all tested conditions, consistent with selective, non-fragmenting oxidation. This work establishes a novel reactor geometry for the photoelectrocatalytic re-valorization of glycerol.