PH value

Calcination

Drying

Citric acid to total metals molar ratio

Cu-Cr ratio

Sample No.

3.32

3 hrs in 700˚C

2 hrs in 160˚C

2:1

0.05

1

5

3 hrs in 700˚C

2 hrs in 160˚C

2:1

0.05

2

7

3 hrs in 700˚C

2 hrs in 160˚C

2:1

0.05

3

9

3 hrs in 700˚C

2 hrs in 160˚C

2:1

0.05

4