Changes in the specific surface area of porous aluminium oxide films during sealing

2006 ◽  
Vol 200 (14-15) ◽  
pp. 4530-4537 ◽  
Author(s):  
M.J. Bartolomé ◽  
V. López ◽  
E. Escudero ◽  
G. Caruana ◽  
J.A. González
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Oxide Films ◽  
Aluminium Oxide

scholarly journals The effect of aluminium oxide on the reduction of cobalt oxide and thermostabillity of cobalt and cobalt oxide

2011 ◽  
Vol 9 (5) ◽  
pp. 834-839 ◽  
Author(s):  
Zofia Lendzion-Bieluń ◽  
Roman Jędrzejewski ◽  
Walerian Arabczyk
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Cobalt Oxide ◽  
Specific Surface Area ◽  
Hydrogen Reduction ◽  
Aluminium Oxide ◽  
Reduction Process ◽  
Oxide Phase ◽  
Recrystallization Process ◽  
Average Size

AbstractDuring precipitation and calcination at 200°C nanocrystalline Co3O4 was obtained with average size crystallites of 13 nm and a well developed specific surface area of 44 m2 g−1. A small addition of a structural promoter, e.g. Al2O3, increases the specific surface area of the cobalt oxide (54 m2 g−1) and decreases the average size of crystallites (7 nm). Al2O3 inhibits the reduction process of Co3O4 by hydrogen. Reduction of cobalt oxide with aluminium oxide addition runs by equilibrium state at all the respective temperatures. The apparent activation energy of the recrystallization process of the nanocrystalline cobalt promoted by the aluminium oxide is 85 kJ mol−1. Aluminium oxide improves the thermostability of both cobalt oxide and the cobalt obtained as a result of oxide phase reduction.

Effect of steaming on physical properties of aluminium hydroxide and aluminium oxide

1990 ◽  
Vol 55 (8) ◽  
pp. 1920-1927 ◽  
Author(s):  
Ro Yong Zun ◽  
Jaroslava Polednová ◽  
Květa Jirátová
Keyword(s):  
Physical Properties ◽  
Partial Pressure ◽  
Specific Surface ◽  
Surface Area ◽  
Water Vapour ◽  
Surface Properties ◽  
Specific Surface Area ◽  
Aluminium Hydroxide ◽  
Aluminium Oxide ◽  
Total Acidity

The effect of partial pressure of water vapour (50-750kPa) in air on physical properties of calcinated aluminium hydroxide AlOOH and aluminium oxide Al2O3 was examined. For both materials it was found that increasing pressure of water vapour leads to a decrease in the specific surface area and to an increase in the diameter of their mesopores. However, changes in the surface properties have not been identical: the total acidity of Al2O3 decreased whereas the acidity of calcinated AlOOH passed through a maximum. The total basicity of Al2O3 increased while that of AlOOH decreased.

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