The Mechanism of Redox Reaction between Palladium(II) Complex Ions and Potassium Formate in Acidic Aqueous Solution

Abstract

The kinetics studies of redox reaction between palladium(II) chloride complex ions and potassium formate in acidic aqueous solutions was investigated. It was shown, that the reduction reaction of Pd(II) is selective in respect to Pd(II) complex structure. The kinetic of the process was monitored spectrophotometrically. The influence of chloride ions concentration, Pd(II) initial concentration, reductant concentration, ionic strength as well as the temperature were investigated in respect to the process dynamics. Arrhenius equation parameters were determined and are equal to 65.8 kJ/mol, and A = 1.12×10 11 s -1 .

The Kinetics of the Redox Reaction of Platinum(IV) Ions with Ascorbic Acid in the Presence of Oxygen

“…The obtained results indicate that with an increase in the chloride ions, an increa the amount of [PtCl6] 2− ions can be expected, because the addition of chloride ions rev hydrolysis process (2). Thus, the amount of [PtCl5(H2O)] − ions in the solution decre The obtained values of [PtCl4] 2− ([Cl − ] = 0.0 M, see Supplementary Materials, Table S1 interesting since they exceed the value of the initial concentration of Pt(IV), i.e., 0.1 This can be explained by the presence of Pt(0) and is described in detail in Section The obtained results indicate that with an increase in the chloride ions, an increase in the amount of [PtCl 6 ] 2− ions can be expected, because the addition of chloride ions reverses hydrolysis process (2). Thus, the amount of [PtCl 5 (H 2 O)] − ions in the solution decreases.…”

“…At a higher pH, only one process takes place, and it relates to the [PtCl 5 (H 2 O)] − reduction. The increased share of the hydrolyzed form of Pt(IV) can be explained by the hydrolysis progress (2), which strongly depends on the pH [26,36].…”

“…Taking into account the used pH value (mainly 2.5) and the registered spectrum intensity (Figure 1a), at the beginning of the process, we have no hydrolyzed form of Pt(IV) (2).…”

“…The reduction process of the Pt(IV) ions was studied in detail by Elding et al [1], Wojnicki et al [2] and Jovanović et al [3]. They showed that the reduction process of Pt(IV) to Pt(II) ions is usually pseudo-first-order, and the reduction process of metal ions depends strongly on the pH of the solution, which is related to the form of the metal precursor or reducing agent.…”

Archives of Metallurgy and Materials

“…However, it cannot be excluded that the reaction involves other mixed complexes such as Pt(IV)-formate or Pt(IV)-Cl-OH -. DFT calculations indicated existence of In Pd(II)-formate complex [20].…”