Table 3: BET results for catalysts containing 50%Fe/50%Mn with different aging times.

Specific surface area ( /g)
Aging time (minute)PrecursorCalcined catalyst (before reaction)Calcined catalyst (after reaction)

0 85.0 82.3 79.1
30 89.3 84.2 80.5
60 93.2 86.6 82.7
120 107.9 98.6 95.6
180 115.8 113.1 109.5
300 119.0 115.6 112.9