Selective Aerobic Oxidation of Aromatic Alcohols Catalyzed by TiO₂: An Insight on the Effect of Surface Fluorination

Abstract:

To achieve better activity, TiO2 was modified through surface fluorination using hydrofluoric acid (denoted as HF-TiO2). The photocatalytic activities of the as-prepared HF-TiO2 and pure TiO2 photocatalysts were evaluated for selective aerobic oxidation of benzyl alcohol. Experimental results indicated that without any loss of selectivity (>98%), distinct rate enhancement can be observed on HF-TiO2 comparing to pure TiO2. To optimize the condition of pretreatment, different concentrations of hydrofluoric acid were also used and the optimal concentration was determined to be 2%. Moreover, the dynamics of benzyl alcohol oxidation followed pseudo-first-order kinetic. By ESR technique and experiments adding different captures, the active specie is determined to be O2 while O2.- and H2O2 were byproducts of the reaction. In a word, this study opens a new path to obtain both high selectivity and conversion yield by TiO2 photocatalysis.

• Periodical: Advanced Materials Research (Volumes 113-116)
• Pages: 327-330
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.113-116.327
• Online since: June 2010
• Authors: Qi Wang
• Keywords: Photocatalytic, Selective Oxidation, Surface Fluorination, TiO₂

References

[1] R. A. Sheldon and J. K. Kochi, in: Metal-Catalysed Oxidations of Organic Compounds. Academic Press: New York (1981).

[2] I. E. Marko, P. R. Giles, M. Tsukazaki, S. M. Brown and C. J. Urch: Science Vol. 274 (1996), p. (2044).

[3] K. Mori, T. Hara, T. Mizugaki, K. Ebitani and K. Kaneda: J. Am. Chem. Soc. Vol. 126 (2004), p.10657.

[4] D. I. Enache, G. J. Hutchings and etc.: Science Vol. 311 (2006), p.362.

[5] D. S. Muggli and J. L. Falconer: J. Catal. Vol. 175 (1998), p.213.

[6] Y. Tamaki, A. Furube, M. Murai, K. Hara, R. Katoh and M. Tachiya: J. Am. Chem. Soc. Vol. 128 (2006), p.416.

[7] V. Augugliaro, T. Caronna, V. Loddo, G. Marci, G. Palmisano, L. Palmisano and S. Yurdakal: Chem. Eur. J. Vol. 14 (2008), p.4640.

DOI: 10.1002/chem.200702044

[8] O. S. Mohamed, A. M. Gaber and A. A. Abdel-Wahab: J. Photochem. Photobiol. A: Chem. Vol. 148 (2002), p.205.

[9] M. Zhang, C. Chen, W. Ma and J. Zhao: Angew. Chem. Int. Ed. Vol. 47 (2008), p.9730.

[10] M. S. Vohra and K. Tanaka: Environ. Sci. Technol. Vol. 35 (2001), p.411.

[11] E. H. Mert, Y. Yalcin, M. Kilic, N. San and Z. Cinar: J. Adv. Oxid. Tech. Vol. 11 (2008), p.199.

[12] J. Lee, W. Choi and J. Yoon: Environ. Sci. Technol. Vol. 39 (2005), p.6800.

[13] C. Minero, G. Mariella, V. Maurino and E. Pelizzetti: Langmuir Vol. 16 (2000), p.2632.

[14] H. Park and W. Choi: J. Phys. Chem. B Vol. 108 (2004), p.4086.