aluminum pourbaix diagram for - uci...
TRANSCRIPT
Pourbaix Diagram for Aluminum Nithya, Xuan, Yipin
Possible Reactions in Al-H2O system
Hydrogen/Oxygen ReactionsE=E° -0.059log ( [H2])/E=
E= E° -(0.059/n)( log ( [H2])/([H+]2))
Reaction CalculationsHalf reaction E0 (V)
Reaction Calculations Al2O3.H2O + 6 H+ + 6 e- → 2 Al (s) + 4 H2O
Reaction CalculationsAl2O3.H2O
H2O
Al
H+
-1825.5 kJ/mol
-237.0 kJ/mol
-0.0 kJ/mol
-0.0 kJ/mol
Reaction Calculations
Reaction Calculations
Reaction Calculations
Al
Al3+ Al2O3 .H2O AlO2-
immunity
corrosion passivation corrosion
Al3+ concentration 10-4 10-2 100
pH 4.064 3.398 2.732
Al3+ concentration 10-4 10-2 100
E -1.7408 -1.7014 -1.662
AlO2- concentration 10-4 10-2 100
pH 8.93 10.93 12.93
