Kinetics of Performic Acid Synthesis and Decomposition

The kinetics of performic acid decomposition was studied with a gas-volumetric technique in which we measured the volume of gas developed over time as a consequence of the reaction. Several kinetic runs were performed in the presence of catalytic amounts of H₂SO₄ and H₃PO₄ and in autocatalytic conditions by mixing solutions of HCOOH and H₂O₂. The trends of the curves of the gas volume (CO₂) released, as a function of time, were all characterized by a more or less long induction time, followed by a straight line. Induction time appeared to be related to the kinetics of performic acid formation, rapidly reaching the equilibrium, while the successive linear trends corresponded to performic acid decomposition. A kinetic model was developed to interpret all the kinetic runs performed. The kinetic parameters with the best fits were determined, and the model was used to also simulate kinetic runs performed by other authors.