The Mechanism and Kinetic Models of the Catalytic Oxidation of Ethylene by p-Benzoquinone in Aqueous–Acetonitrile Solutions of Pd(II) Cationic Complexes

A kinetic study of ethylene oxidation to acetaldehyde by p-benzoquinone in the Pd(OAc)2–HClO4−LiClO4–CH3CN–H2O system has been carried out under conditions when palladium(II) cationic complexes exist at a molar fraction of water of 0.67 and 30°С. For a reaction that mostly lead to the formation ofPd(CH3CN)(H2O) 3 2+ two-route mechanism and a kinetic model have been proposed that describe adequately the experimental dependence of the reaction initial rate on the concentration of p-benzoquinone, HClO4, and palladium. The model takes into account previous findings on the H2O/D2O and C2H4/C2D4 kinetic isotope effects and the important role of Pd(0) quinone complexes.