Photocatalytic oxidation of aromatic hydrocarbons
- Iowa State Univ., Ames, IA (United States)
In acidic aqueous solutions UO{sub 2}{sup 2+} serves as a photocatalyst ({lambda}{sub irr} {plus_minus} 425 nm) for the oxidation of benzene by H{sub 2}O{sub 2}. Under conditions where 50% of the excited state {sup *}UO{sub 2}{sup 2+} is quenched by H{sub 2}O{sub 2} (k = 5.4 x 10{sup 6} M{sup {minus}1}s{sup {minus}1}) and 50% by benzene (k = 2.9 x 10{sup 8} M{sup {minus}1} s{sup {minus}1}), the quantum yield for the formation of phenol is 0.70. The yield does not change when benzene is replaced by benzene-d{sub 6}, but decreases by a factor of {approximately}4 upon the change of solvent from H{sub 2}O to D{sub 2}O. Photocatalytic oxidation of toluene by UO{sub 2}{sup 2+}/H{sub 2}O{sub 2} produces PhCHO, PhCH{sub 2}OH, and a mixture of cresols with a total quantum yield of 0.28 under conditions where 50% of {sup *}UO{sub 2}{sup 2+} is quenched by H{sub 2}O{sub 2}. The quenching of {sup *}UO{sub 2}{sup 2+} by benzene and substituted benzenes takes place with k > 10{sup 8} M{sup {minus}1} s{sup {minus}1}. The system UO{sub 2}{sup 2+}/t-BuOOH/C{sub 6}H{sub 6}/hv does not result in the oxidation of benzene, but instead yields methane and ethane.
- OSTI ID:
- 281962
- Journal Information:
- Inorganic Chemistry, Journal Name: Inorganic Chemistry Journal Issue: 13 Vol. 35; ISSN 0020-1669; ISSN INOCAJ
- Country of Publication:
- United States
- Language:
- English
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