Perovskite catalytic ozonation of pyruvic acid in water: Operating conditions influence and kinetics

The catalytic ozonation of pyruvic acid in the presence of the perovskite LaTi0.15Cu0.85O3 has been carried out. Typical operating parameters like ozone inlet concentration, catalyst dosage, protons concentration (below 0.01 M) and temperature (below 303 K) exert a positive influence on the pyruvic acid depletion rate. Regarding the pyruvic acid concentration, a zero kinetic order holds for most of experiments. Under the conditions applied, the process is controlled by the chemical reaction. Acetic and oxalic acids are the only intermediates formed with a higher selectivity towards the former (above 90–95%). The similarities between experimental total organic carbon (TOC) and calculated from the contributions of remaining pyruvic acid and formed acetic and oxalic acids corroborate the previous statement. The activity of the catalyst is enhanced after the first usage. Thereafter, four consecutive reutilisations of the catalyst indicate the high stability of the solid. The process is acceptably simulated by a Langmuir–Hinshelwood kinetic expression derived from adsorption of ozone and pyruvic acid onto different active sites.