Improvement the Activity and Selectivity of Fenton System in the Oxidation of Alcohols
Table 2
Effect of additives for the oxidation of benzyl alcohol to benzaldehyde at 25°Ca.
Entry
Catalyst
Amountb (mol%)
Time (h)
Conv. (%)
Sel.c (%)
1
FeSO4/NaH2PO4
2.5%/1%
0.5
3.8
95.9 (91 : 9)
2
2
8.6
95.1 (90 : 10)
3
4
9.5
91.2 (90 : 10)
4
FeSO4/NaH2PO4
2.5%/2.5%
0.5
1.1
98.2 (92 : 8)
5
2
1.9
98.2 (93 : 7)
6
FeSO4/NaH2PO4
2.5%/10%
0.5
1.1
98.8 (92 : 8)
7
19
1.3
98.9 (91 : 9)
8
FeSO4/KBr
2.5%/10%
0.5
3.4
100 (89 : 11)
9
FeSO4/NaBF4
2.5%/10%
0.5
1.7
>99.9 (100 : 0)
10
FeSO4/KH2PO4
2.5%/2.5%
0.5
1.2
98.3 (93 : 7)
11
FeSO4/N1111Gly
2.5%/2.5%
0.5
20.6
91.7 (96 : 4)
12
FeSO4/N2111OAc
2.5%/2.5%
0.5
25.7
98.4 (87 : 13)
13
FeSO4/[HMIM][HSO4]
2.5%/10%
0.5
1.3
>99.9 (100 : 0)
20 mmol of benzyl alcohol, 2.2 equiv. of H2O2 (30 wt% in water). H2O2 was added with a syringe pump by 0.2 mL/min speed. bAmount of catalyst. cTotal selectivity to benzaldehyde and benzoic acid. Value in parentheses means the ratio of benzaldehyde/benzoic acid.
