METHOD FOR DETERMINING OF THE TRUE SURFACE OF THE ELECTROLYTIC PRECIPITATES OF PLATINUM DEPOSITED ON THE CARBON-CONTAINING ELECTRODE BY THE METHOD OF INVERSION VOLTAMMETRY

摘要

FIELD: chemistry.;SUBSTANCE: invention relates to electrochemistry, namely to the study and analysis of materials by determining the electrochemical parameters for voltammetric measurements, and can be used to evaluate the surface of electrodes modified with platinum, as well as surfaces of highly developed micro- and nanoporous catalysts with precipitates of this metal. Method for determining the true surface of electrolytic precipitates of platinum deposited on a carbon-containing electrode by the method of inversion voltammetry is that conduct electrooxidation of mercury (II) ions with a concentration of 10 mg/dm³ on the surface of a carbon-containing electrode in a constant-current regime from solutions of 1 M HCl at a potential E_E of –0.8 V for 180 s and the rate of change of potential W of 0.08 V/s. Then register the peak-point current of the mercury electrooxidation from the surface of the carbon-containing electrode I_d observed at a potential of +0.1 V of comparison CSE (chloride silver electrode), and determine the surface of the carbon-containing electrode without a platinum precipitate S₀. Add additives of platinum (IV) ions in the concentration range of 0.03 to 0.15 mg/dm³, conduct electrooxidation of platinum (IV) ions in the presence of 10 mg/dm³ ions of mercury (II) at a potential E_E –0.8 V for 180 s and the rate of change of potential W of 0.08 V/s. Register values of the peak area of electrooxidation of mercury from two binary precipitates with platinum Q₂ observed in the range of potentials of +0.3 to +0.6 V. Plot a graph of the peak area of electrooxidation of mercury from the surface of the carbon-containing electrode Q₁ dependency on the concentration of platinum (IV) ions. By extrapolating the graph, the limit value Q₀ and determine the true surface of electrolytic precipitates of platinum by a certain formula, and the surface of the carbon-containing electrode without the platinum precipitate is determined from the proposed expression.;EFFECT: technical result of the invention consists in determining the true surface of platinum precipitates at different degrees of filling them with the surface of the carbon-containing electrode.;1 cl, 3 dwg, 1 tbl