SU1348666A1 - Device for determining temperature effects on electrode - cathode boundary - Google Patents

Abstract

The invention can be used to study the energy and mechanism of electrode processes in scientific research. The purpose of the invention is to increase the information content in the study of electrode processes occurring in dynamic electrolysis modes. In the electrolytic cell 1 is placed a working temperature sensor 2, made in the form of a ceramic capacitor. One of the plates 3 is replaceable, made of metal foil, is in contact with the electrolyte solution, serves as the working electrode of the cell and, together with electrode 4, is connected to source 5 of polarizing current. The temperature changes during the electrolysis process are determined relative to the temperature of the solution measured by the temperature sensor 6, which is included in the output parameter conversion circuit 7 into the recorded signal. 3il. with S (L you move on: registration CO N 00 05 05 O5 ig.1

Description

The invention of thermochemical measurements and can be used to study the energy and mechanism of electrode processes in scientific research and to improve technological processes in electrochemical production.

The aim of the invention is to increase the information content in the study of electrode processes occurring in dynamic electrolysis modes.

Fig. 1 shows a block diagram of a device for determining temperature effects at the electrode-solution boundary; Fig. 2 shows schematically the structure of a working temperature sensor; Fig. 3 shows the dependence of the temperature change at the electrode-solution interface on the potential of the electrode in the Pt / CuBr system,.

In the electrolytic cell 1, the working temperature sensor 2 measures the temperature at the border of the working electrode – solution, which is insulated in the form of a ceramic capacitor. One of the plates 3 of this

The temperature effects of cathode reduction of copper (Cu) to metallic copper on a platinum cathode in a CuBr solution with a concentration of 0.25 mol / l were determined, the cell was thermostated at t 25 ° C, the potentiometer of the working electrode was developed 5 mV / s. as a source, a metal foil floor is in contact with the electrolyte solution and serves as the working electrode of the cell. The metal of the electrode plate determines the gizing current that served as a potentiostat for the purpose of studying specific electro-G1-5827M. The working electrode is a cell of chemical objects. This worker was a C 560 pF ceramic capacitor lining, made of platinum foil with a thickness of 40 0.05 mm. The reference sensor was a ceramic capacitor with the same characteristics. The temperature sensors were connected to the conversion circuit and the auxiliary electrode A is connected to the source of the polarizing current 5, and together they form an electrochemical circuit. The temperature changes during the electrolysis process are determined with respect to the temperature of the solution, measured by the reference temperature sensor 6, which is also a ceramic capacitor, but electrically isolated from the electrolyte solution.

Sensors are included in the circuit 7 for converting the output parameter into a recorded signal, for example, in an oscillator circuit that converts capacitance into frequency, giving the difference between the output parameters of the reference and operating temperature sensors. The recorded signal can be both digital and analog and can be recorded by a digital printing device50

No output parameters in the recorded signal. The temperature change was recorded by a two-coordinate recorder of the PDP4 type. The output frequency was transformed into a voltage using a frequency meter 43–7 and recorded by a two-coordinate recorder of the PDPA type.

The dependence obtained by the proposed method provides information about the copper reduction mechanism, the staging process and the formation of the surface film under certain conditions, and also makes it possible to judge the processes accompanying the electrode peaKiuni. Points of inflection

55

or recorded as a chart by a chart recorder. The working temperature sensor 2 contains a 1t replaceable capacitor plate, which is a thin metal foil attached to a ceramic dielectric 2 by soldering it to a deposited capacitor plate, from which the surface insulator, the second capacitor plate 8, and the capacitor terminals 9 and 10 are removed. to the capacitance conversion circuit into the recorded signal, by terminal 10 the capacitor plate as an electrode of an electrolytic cell is connected to a polarizing current source 5, a holding body 11, the insulation adhesive 12 for reinforcing the capacitor and the protection against the penetration of solution to the inner plate of the capacitor.

The device works as follows.

The temperature effects of cathode reduction of copper (Cu) to metallic copper on a platinum cathode in a CuBr solution with a concentration of 0.25 mol / l were determined, the cell was thermostated at t 25 ° C, the potentiometer of the working electrode was developed 5 mV / s. as a source of polarization current, the potentiometer G1-5827M served. The working electrode of the cell was a C-560 pF ceramic capacitor lining, made of platinum foil 0.05 mm thick. The reference sensor was a ceramic capacitor with the same characteristics. Temperature sensors connected to the transform circuit 50

No output parameters in the recorded signal. The temperature change was recorded by a two-coordinate recorder of the PDP4 type. The output frequency was transformed into a voltage using a frequency meter 43–7 and recorded by a two-coordinate recorder of the PDPA type.

The dependence obtained by the proposed method provides information about the copper reduction mechanism, the staging process and the formation of the surface film under certain conditions, and also makes it possible to judge the processes accompanying the electrode peaKiuni. Points of inflection

55

and the breaks in the curve depicted in FIG. 3 correspond to the beginning of the electrode stages of electroreduction

7. CHC and water, and also indicate the moment of formation and removal of the surface film during the electrolysis of an aqueous solution of CuBr. So, electro

ny process begins with the reaction of the restoration of t - the establishment of C to C according to

Cu + and is accompanied by the release of heat.

Since the solubility product of CuBr is low (pKg (CuBr) 8.2), when Cu ions reach the concentration of the solubility product, a solid phase of CuBr is formed. Since the Cu ions are formed on the electrode, they are bound here by the Br ions to the insoluble CuBr surface film. This moment is fixed on the curve (inflection point). A sharper temperature increase due to the deterioration of the heat sink from the electrode due to this film.

The next bend in the curve, corresponding to the onset of a sharp cooling in the pre-electrode zone, corresponds to the stage of copper reduction to metallic copper and indicates the removal of

surface film by electro-restoration, according to the equation CuBr + с -.Cu ° + Вг,

The minimum on the curve corresponds to the beginning.

electro-water recovery,

-t- 2e-- 201G, the release of heat.

2 N, 0

accompanying

Claims (1)

IQ Invention Formula A device for determining temperature effects at the electrode-solution interface containing a working and a reference temperature sensor connected to a recorder and placed in an electrolytic cell with electrodes connected to a source of polarizing current that differs 20 informativeness in the study of electrode processes occurring in dynamic modes of electrolysis, in it the working and reference temperature sensors are made in the form of ceramic capacitors, and one of the plates of the working temperature sensor, made replaceable from metal foil, is an electrode of an electrolytic cell. 0, 0.3 0.2 V about -0,. 0.1 FIG. J Compiled by Y. Kletsko Editor E. Kopcha Tehred M. Khodanich Proofreader V. Gnrn to Order 5180/40 Circulation 775 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4