Photocatalytic degradation of citric acid under different conditions: TiOb>2 b> heterogeneous photocatalysis against homogeneous photolytic processes promoted by Fe(III) and Hb>2 b>Ob>2
- 作者：Natalia Quici ; Marí ; a E. Morgada ; Raquel T. Gettar ; Michè ; le Bolte ; Marta I. Litter
- 关键词：Heterogeneous photocatalysis ; TiO
- 刊名：Applied Catalysis B ; Environmental
- 出版年：2007
- 期刊代码：4_09263373
- 类别：ce
- 出版时间：15 February 2007
- 卷：71
- 期：3-4
- 页码：117-124
- 文件大小：460 K
摘要
Degradation of citric acid (Cit) at relatively high concentrations by photocatalysis over TiOb>2 b> under air bubbling and near UV-light was tested under different conditions. The reaction was improved by addition of Hb>2 b>Ob>2 b>, Fe(III) or both. Minor amounts of Hb>2 b>Ob>2 b> were effective to enhance the oxidation and the mineralization. Hb>2 b>Ob>2 b> addition impacts more on the initial rate, while the effect of Fe(III) is more important after prolonged irradiation. The kinetic profiles were analyzed and compared, and the best ratio of reagents was found (1:1:1 Hb>2 b>Ob>2 b>/Cit/Fe molar ratio). However, a lower amount of Fe (1:1:0.2 Hb>2 b>Ob>2 b>/Cit/Fe ratio) was also effective. Similar experiments under the optimal conditions in the absence of TiOb>2 b> were performed for comparison. When both Hb>2 b>Ob>2 b> and Fe(III) were present, the behavior with and without TiOb>2 b> was very similar. So far, 3-oxoglutaric acid was detected as a reaction intermediate. A mechanistic analysis is initiated to explain some features of these complex systems.