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Investigations of fast electrode processes by means of a micro-ring electrode in turbulent pipe flow

1978; Elsevier BV; Volume: 87; Issue: 1 Linguagem: Inglês

10.1016/s0022-0728(78)80382-9

2590-2954

C. Bernstein, A. Heindrichs, W. Vielstich,

Electrochemical sensors and biosensors

A micro-ring electrode in turbulent pipe flow is presented as a useful tool in hydrodynamic voltammetry. The high rate of mass transfer attainable with this system enables steady state measurements of fast electrode reactions with rate constants up to 5 cm s−1. The construction of the flow system and the electrode arrangement are described. The theory of mass and charge is discussed and an expression for determining kinetic parameters from current-potential curves is derived. The technique is illustrated using the redox couple Fe[CN]64−/Fe[CN]63−. The rate constant was found to be 0.12 cm s−1, the transfer coefficient 0.5 at 25°C. A comparison with other methods capable for the study of fast electrode processes is made.