Linear sweep voltammetry at the tubular electrode: Theory of EC mechanisms

Hydrodynamic voltammetry at the interface between immiscible electrolyte solutions: Numerical simulation of the voltammetric response

“…The E 1/2 is dependent on the ratio of mass-transport in the organic and aqueous phases [38], hence decreasing the organic phase flow rate results in a shift of E 1/2 to more positive potentials. This behaviour is analogous to that of an EC reaction seen in channel and other hydrodynamic electrodes, where the E 1/2 shifts to more negative or positive values [39,40], for an oxidation or reduction, respectively, as the rate constant of the chemical reaction is increased.…”

“…In this case decreasing the aqueous flow rate causes a shift of E 1/2 to more negative potentials. This shift in E 1/2 is again analogous to an EC reaction seen in hydrodynamic electrodes [39,40].…”

Chemical instability promotes apparent electrochemical irreversibility: Studies on the electrode kinetics of the one electron reduction of the 2,6-diphenylpyrylium cation in acetonitrile solution

“…The tubular flow cell is a non-uniformly accessible hydrodynamic electrode which has been used extensively in experimental investigations [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], with insight gained into reaction mechanisms and kinetics by monitoring the changing current with varying rates of mass transport. The behaviour of tubular flow cells has been developed via numerical simulations [19][20][21][22], some of which noted that for practical electrodes where the diffusion layer is thin compared to the radius of the tube, the problem may be treated as similar to that of the channel flow cell. The numerical approach has been applied to the EC [21] and EC 2 [19] mechanisms at a tubular flow cell, to study the potential shift of the voltammetric wave with varying kinetic parameters.…”

“…The behaviour of tubular flow cells has been developed via numerical simulations [19][20][21][22], some of which noted that for practical electrodes where the diffusion layer is thin compared to the radius of the tube, the problem may be treated as similar to that of the channel flow cell. The numerical approach has been applied to the EC [21] and EC 2 [19] mechanisms at a tubular flow cell, to study the potential shift of the voltammetric wave with varying kinetic parameters. In these studies a change in waveshape was observed with varying kinetics, although the magnitude of this effect was not quantified.…”

Theory of EC Processes under Steady State Conditions at Microdisk Electrodes: Reversible and Irreversible Homogeneous Kinetics

“…In the limit of high K eq the EC rev process is essentially EC irr and so we see a very similar variation in half-wave potential as shown in Figure and discussed above. When the equilibrium lies well to the right, we can equate the Gibbs energy change of the electrochemical step to that of the homogeneous step as demonstrated for the tubular electrode by Thompson . For A ⇌ B we have and for B ⇌ C Therefore equating the two expressions yields the result that This expression allows the calculation of the limiting half-wave potential for a given value of K eq , and predicts that at high K f a plot of half-wave potential as a function of K eq will have a slope of 2.3 in the linear region.…”