Kinetics of the oxygen evolution reaction on rhodium electrodes with different electrocatalytic activity

C Pallotta,N.R De Tacconi,A.J Arvia

doi:10.1016/s0022-0728(81)80169-6

Abstract

Kinetics of the oxygen evolution reaction on rhodium electrodes with different electrocatalytic activity

Highlights

Instituto de Investigaciones Fisicoquimicas TeOricas y Aplicadas. (INIFTA), DivisiOn Electroquimica, Sucursal 4 --Casilla de Correo 16 (1900), La Plata (Argentina)
It has recently been demonstrated [1] that the potentiodynamic behaviour of Rh/H2SO4(aq) interphases in the potential range of the thermodynamic stability of bulk water is associated with at least two-well defined and different electrochemical characteristics of rhodium, which were referred to as Aand B-type Rh electrodes [ 1 ]
The aim of the present report is to show the electrocatalytic difference of A- and B-type electrodes for the 02 evolution reaction, on the basis that the corresponding structures of the electrodes remain stable during the time the electrochemical measurements last

Summary

Short communication

Instituto de Investigaciones Fisicoquimicas TeOricas y Aplicadas. (INIFTA), DivisiOn Electroquimica, Sucursal 4 --Casilla de Correo 16 (1900), La Plata (Argentina). The A-type Rh electrodes are characterized by an Eli potentiodynamic profile in the 0--1.60 V range (vs RHE), which involves the already known contributions of the H-electrosorption/H-electrodesorption (0.0--0.24 V)and the O-electrosorption/O-electrodesorption (0.6--1.6 V) (Fig. 1) These electrodes were first subjected to repetitive triangular potential sweeps (RTPS) in the 0---1.60 V range at one preset potential sweep rate (v) in the 0.03 V s -1 ~< v ~< 0.3 V s-' range in order to attain a stabilized E / / display. These electrodes are characterized by a stabilized potentiodynamic Eli profile, including a fast response conjugated redox system in the 1.54--1.66 V range Once this situation has been attained v is changed from 80 to 0.03 V s -1 ~< v ~< 0.3 V s -I and the anodic potential limit is extended to 1.9 V (Fig. 1) to cover a part of the 02 evolution potential range.

1JJ tm

Findings

ACKN OWLEDG EME NTS