Effect of Composition on the Electrocatalytic Activity of the Ternary Oxide Ru0.3Ti ( 0.7 − x ) Sn x  O 2 : I . Oxygen Evolution from Solutions

Abstract

The electrocatalytic activity of ternary oxides of general formula Ru0.3Ti(0.~_=>Sn=O2 for 02 evolution from 1 mol dm -3 HC104 solution has been studied as a function of x by current-potential curves and reaction order determination. The surface state of the electrodes has been monitored by voltammetric curves before and after each run of experiments. The mechanism of O2 evolution has been found not to depend on oxide composition, whereas the electrocatalytic activity has been observed to rise as the SnO2 content increases. The surface charge drops dramatically after extensive 02 evolution, thus indicating collapse of the surface morphology. The open-circuit potential and the shape of the voltammetric curves have also been used as diagnostic parameters. The present results show that SnO2 activates RuO2 + TiO2 electrodes, consequently decreasing their stability.

Surface Characterization and Electrocatalytic Properties of the Ti/Ir0.3Ti(0.7-x)Pb x O2-Coated Electrodes for Oxygen Evolution Reaction in Acidic Media

“…The broad peak observed at 0.85 V has been attributed to the Ir(III)/Ir(IV) transition 12 which suggests that the surface electrochemistry is controlled by this redox transition. All these results are similar to those previously reported for Ti/Ru 0.3 Ti (0.7-x) Sn x O 2 -coated 11 and Ti/Ir 0.3 Ti (0.7-x) Ce x O 2 -coated 12 electrodes.…”

“…23 The dependence of q a on the composition of the layer is presented in Figure 4, which reveals that the anodic charge density increases A maximum of q a with composition is also reported for Ti/ Ru 0.3 Ti (0.7-x) Sn x O 2 -coated, 11 for Ti/Ir 0.3 Ti (0.7-x) Ce x O 2 -coated 12 and for Ti/Ru 0.3 Ti (0.7-x) Ce x O 2 -coated 14 electrodes. It is related to the deposition of the oxide as a very fine crystallite structure during the thermal decomposition of the precursors, due to the non-intimate mixing between the individual components.…”

“…It is related to the deposition of the oxide as a very fine crystallite structure during the thermal decomposition of the precursors, due to the non-intimate mixing between the individual components. [11][12][13][14] Figure 4 also shows that, after extensive oxygen evolution (Tafel experiments), the values of q a slightly increase. This behavior is explained by Boodts and collaborators [11][12][13][14][15][16] as a result of an increase of the degree coverage of the electrode surface by the active species OH, resulting from water discharge, leading to additional activation of the surface sites.…”

“…10 A third component can be added to the electrocatalyst layer to modify the electrochemical and electrocatalytical properties of the electrodes. Boodts and Trasatti [11][12][13][14][15][16] have carried out systematic investigations of the physicochemical and electrochemical properties of ternary DSA electrodes using PtO 2 , CeO 2 and SnO 2 as the third component. The methodology used by these authors is to substitute TiO 2 by one of these oxides in the 30 mol % RuO 2 + 70 mol %TiO 2 or 30 mol % IrO 2 + 70 mol % TiO 2 systems.…”

Hydrogen production by alkaline water electrolysis

“…86,87 Recently, Ru-rich Pt electrocatalysts and titanium (Ti)-or titanium carbide (TiC)-supported electrocatalysts for OER have been suggested. 88,89 Bifunctional electrocatalysts, which can work for both oxygen evolution and oxygen reduction, have also been proposed for water electrolysis. A typical bifunctional electrocatalyst is composed of a noble metal oxide such as IrO 2 .…”