Electrochemical kinetics of the Ti(IV)/Ti(III) couple in sulfuric acid

Voltamperometric study of the titanium IV–oxalate complexes

“…The same reaction scheme is valid for Ti(IV) species in H 2 SO 4 solutions greater than 4 M [2]. Of course, in this case, S i refers to titanium complexes formed with HSO À 4 ligand.…”

“…As part of a systematic review of the electrochemical behavior of Ti(IV)/Ti(III) couple in acidic media [1,2], the catalytic reduction of the oxalato complexes of Ti(IV) is currently being investigated. For the interpretation of the results, values of the concentration equilibrium constants for the chemical reaction between the mono and the dioxalato complexes of Ti(IV) are necessary.…”

“…The electrochemical reduction of Ti(IV) to Ti(III) at the mercury electrode in HClO 4 up to about 2 M behaves irreversibly without apparent chemical complications [2]. For these solutions, ion exchange elution techniques showed that two ionic forms of Ti(IV) predominate: TiðOHÞ þ 3 þ H þ ¼ TiðOHÞ 2þ 2 þ H 2 O for which the concentration quotient is 2 [3].…”

Theory of square-wave voltammetry of quasireversible electrode reactions using an inverse scan direction

“…At higher frequencies the net response of electrode reaction that is controlled by the charge transfer kinetics may split into two peaks originating from the separated reduction and oxidation electrode processes [5]. The method was used for the explanation of electrode mechanisms and the determination of kinetic parameters of electrode reactions [5][6][7][8][9]. In this short communication a relationship between peak potentials and the logarithm of frequency in SWV with inverse scan direction is analyzed theoretically and the critical kinetic parameters are calculated for the standard experimental conditions, as it was done in the classical SWV previously [1,5,10].…”

Determination of Ti(IV) at low levels by voltammetry

“…Well-formed voltammograms and accurate current readings are obtained only with the mercury drop electrode [2][3][4]. The investigation of the electrochemical kinetics of the Ti(IV)/Ti(III) couple in sulfuric acid and in acid oxalate media [5][6][7][8], enabled us to define and validate the experimental conditions for determining Ti(IV) at minor or trace levels by DC polarography, square wave voltammetry (SWV) and differential pulse voltammetry (DPV) at the static mercury drop electrode (SMDE).…”