KINETIC MODELING FOR WET AIR OXIDATION OF FORMIC-ACID ON A CARBON-SUPPORTED PLATINUM CATALYST

A study of the intrinsic kinetics of the oxidation of formic acid over a 1% Pt/C catalyst has been performed, at oxygen concentrations in wa ter varying from 0.6 to 2.8 mol m(-3) and at formic acid concentration s varying from 30 to 400 mol m(-3). Experiments were performed in a co ntinuous-flow stirred slurry reactor. To avoid mass transfer limitatio n of oxygen, a temperature interval from 282 to 293 K and a total pres sure in the reactor of 0.6 MPa has been used. The pH interval of the e xperiments ranged from 1.1 to 13.0. Single response non-linear regress ion has been used to fit the parameters for a kinetic model. The propo sed model can predict the steady-state disappearance rate of formic ac id, as a function of the oxygen concentration, the formic acid concent ration, the temperature and of the pH. Electrochemical experiments hav e been carried out for a better understanding of the pH effect on the formic acid oxidation. (C) 1997 Elsevier Science B.V.