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The polarographic reduction of perbromate and its use as a probe of double layer structure

1975; Elsevier BV; Volume: 58; Issue: 1 Linguagem: Inglês

10.1016/s0022-0728(75)80349-4

2590-2954

Robert de Levie, Maria Nemes,

Membrane-based Ion Separation Techniques

o1.The reduction of perbromate has been studied in dilute (1, 10 and 100 mM) aqueous alkali halide solutions, in which they exhibit a polarographic minimum and an associated negative faradaic admittance.2.In electrolytes which exhibit only weak specific ion adsorption (e.g., 0.1 M NaF), the perbromate reduction is characterized by a low and apparently potential-dependent transfer coefficient.3.The marked effects of the adsorbable ions Cl−, Br− and I− can be accounted for quantitatively by the Frumkin correction, using classical double layer theory and assuming that the intrinsic perbromate reduction rate is not affected by specific halide adsorption.4.The 1 mM electrolyte solutions, the charge density due to specifically adsorbed Cl− and F− almost equals the electronic charge density, but the double layer potentials do not vanish.5.Specific advantages of the use of anions as quantitative probes of double layer structure have been outlined. The reduction of perbromate has been studied in dilute (1, 10 and 100 mM) aqueous alkali halide solutions, in which they exhibit a polarographic minimum and an associated negative faradaic admittance. In electrolytes which exhibit only weak specific ion adsorption (e.g., 0.1 M NaF), the perbromate reduction is characterized by a low and apparently potential-dependent transfer coefficient. The marked effects of the adsorbable ions Cl−, Br− and I− can be accounted for quantitatively by the Frumkin correction, using classical double layer theory and assuming that the intrinsic perbromate reduction rate is not affected by specific halide adsorption. The 1 mM electrolyte solutions, the charge density due to specifically adsorbed Cl− and F− almost equals the electronic charge density, but the double layer potentials do not vanish. Specific advantages of the use of anions as quantitative probes of double layer structure have been outlined.