14
2 Comprehensive Electrochemistry of Tc …
Fig. 2.3 The potential pH diagram for Ru-H 2 O system, (left panel) c 0
Ru = 10 −6 mol dm −3 (right
panel) c 0
Ru = 10 −4 mol dm −3 (reprinted with permission from Povar and Spinu (2016). Copyright
2016 Creative Common License)
Fig. 2.4 E h -pH diagram
obtained from the equations
published by Pourbaix
(reprinted with permission
from Schrebler et al. (2001).
Copyright 2001 Elsevier)
When the total concentration of ruthenium increases the area of stability of
Ru(OH)
2+
2 ions becomes more narrow while for Ru polymeric species an opposite
effect is observed. Other than ionic forms of Ru present in the diagrams include Ru 2 O 5
and Ru(OH) 3 . The existence of Ru(OH) 3 makes this element similar to rhenium for
which Re 2 O 3 is observed (Fig. 2.4). Another one aspect that is characteristic of Re is
the presence of oxides with higher oxidation states, e.g., ReO 3 , that is stable in acidic
2 Comprehensive Electrochemistry of Tc …
Fig. 2.3 The potential pH diagram for Ru-H 2 O system, (left panel) c 0
Ru = 10 −6 mol dm −3 (right
panel) c 0
Ru = 10 −4 mol dm −3 (reprinted with permission from Povar and Spinu (2016). Copyright
2016 Creative Common License)
Fig. 2.4 E h -pH diagram
obtained from the equations
published by Pourbaix
(reprinted with permission
from Schrebler et al. (2001).
Copyright 2001 Elsevier)
When the total concentration of ruthenium increases the area of stability of
Ru(OH)
2+
2 ions becomes more narrow while for Ru polymeric species an opposite
effect is observed. Other than ionic forms of Ru present in the diagrams include Ru 2 O 5
and Ru(OH) 3 . The existence of Ru(OH) 3 makes this element similar to rhenium for
which Re 2 O 3 is observed (Fig. 2.4). Another one aspect that is characteristic of Re is
the presence of oxides with higher oxidation states, e.g., ReO 3 , that is stable in acidic