Photo-electro-catalytic oxidation reactions of 1,6-hexanediol were carried out in a coil-type continuous-flow microreactor with an immobilized TiO2 catalyst material. Bio-based adipic acid was formed as the only intermediate product before the total mineralization process. The production was stable, enabling green, selective and continuous resource conversion, but with low, non-optimized yields. In addition, the catalyzed chemical kinetics was modeled, based on mechanisms as well as approximated rate-determining steps. The Butler-Volmer relation was used for activation. The electro-catalytic oxidative pathway was demonstrated to dominate over photo-catalysis, also on account of the band gap characteristics of the titania nanotube electrode.