Abstract
In this work a significant improvement of VOx/TiO2 photocatalytic activity in the selective partial oxidation of ethanol to acetaldehyde was achieved by the simultaneous irradiation with light emitting phosphorescent particles and UVA-LEDs as external light source. Photocatalytic tests were carried out in a gas-solid photocatalytic fluidized bed reactor at high illumination efficiency, in which the bed is constituted by VOx/TiO2 photocatalyst at nominal V2O5 content of 5 wt% and suitable selected phosphors, diluted with glass spheres. In this way, phosphors were fluidized together with the catalyst, excited by external UVA-LEDs, emitting their stored energy in close proximity to the catalyst. In the absence of phosphors the ethanol consumption rate initially grows linearly with initial alcohol concentration, then bends towards an asymptotic value for initial ethanol concentration higher than 0.5 vol%. By contrast, when phosphors are present, the ethanol consumption rate increased linearly in the overall range. In all cases acetaldehyde was the main product detected in gas phase with a selectivity of about 97%, ethylene and carbon dioxide the by-products. The results evidenced that the presence of phosphors allowed improved photon transfer, increasing the apparent quantum yield from 2 to 30% together with a high photoreactivity.
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References
V. Subbarayan, S. Arumugam and T. Punniyamurthy, Tetrahedron Lett., 2006, 47, 923.
R. A. Sheldon and J. K. Kochi, Metal-Catalyzed Oxidation of Organic Compounds, Academic Press, New York, 1981.
M. Hudlicky, Oxidations in Organic Chemistry, American Chemical Society, Washington, DC, 1990.
U. R. Pillai and E. Sahle-Demessie, J. Catal, 2002, 211, 434.
M. Gomez, L. Arrua and M. C. Abello, Ind. Eng. Chem. Res., 1997, 36, 3468.
N. Quaranta, J. Soria, V. Cortes Corbaran and J. L. G. Fierro, J. Catal, 1997, 171, 1.
R. Tesser, V. Maradei, M. Di Serio and E. Sannteacesaria, Ind. Eng. Chem. Res., 2004, 43, 1623.
O. S. Mohamed, A. E. M. Gaber and A. A. Abdel-Wahab, J. Photochem. PhotobioL, A, 2002, 148, 205.
S. Farhadi, M. Afshari, M. Maleki and Z. Badazadeh, Tetrahedron Lett., 2005, 46, 8483.
G. Palmisano S. Yurdakal, V. Augugliaro, V. Loddo and L. Palmisano, Adv. Synth. Catal, 2007, 349, 964.
P. Ciambelli, D. Sannino, V. Palma and V. Vaiano, Catal. Today, 2005, 99, 143.
P. Ciambelli, D. Sannino, V. Palma and V. Vaiano, Stud. Surf. Sci. Catal, 2005, 155, 179.
P. Ciambelli, D. Sannino, V. Palma, V. Vaiano and R. I. Bickley, Appl. Catal, A, 2008, 349, 140.
P. Ciambelli, V. Palma, D. Sannino, S. Vaccaro and V. Vaiano Stud. Surf Sci. Catal, 2007, 172, 453.
P. Ciambelli, D. Sannino, V. Palma, V. Vaiano, P. Eloy, F. Dury and E. M. Gaigneaux, Catal. Today, 2007, 128, 251.
P. Ciambelli, D. Sannino, V. Palma, V. Vaiano, P. Eloy, F. Dury and E. M. Gaigneaux, Catal. Today, 2009, 141, 367.
P. Ciambelli, D. Sannino, V. Palma and V. Vaiano Int. J. Photoenergy, 2008, DOI: 10.1155/2008/258631.
T. Carlson and G. L. Griffin, J. Phys. Chem., 1986, 90, 5896.
D. Masih, H. Yoshitake and Y. Izumi, Appl. Catal, A, 2007, 325, 276.
T. Van Gerven, G. Mul, J. Moulijn and A. Stankiewicz, Chem. Eng. Process., 2001, 46, 781.
P. Ciambelli, D. Sannino, V. Palma, V. Vaiano, under PCT. application WO2009IT00239 20090529.
P. Ciambelli, D. Sannino, V. Palma, V. Vaiano and R. S. Mazzei, Photochem. PhotobioL Sci., 2009, 8, 699.
P. Ciambelli, D. Sannino, V. Palma and V. Vaiano, Int. J. Photoenergy, 2009, DOI: 10.1155/2009/709365.
V. Palma, D. Sannino, V. Vaiano and P. Ciambelli, Ind. Eng. Chem. Res., 2010, DOI: 10.1021/iel005383.
S. L. Issler and C. C. Torandi, J. Alloys Compd, 1995, 229, 54.
W. Liedy, PCT Int. Appl. (2003), WO 2003086618.
C. Anderson and A. J. Bard, J. Phys. Chem. B, 1997, 101, 2611.
V. Vaiano, Heterogeneousphotocataly tic selective oxidation of cyclohex-ane, PhD. Thesis University of Salerno, 2006.
L. Alemany, L. Lietti, N. Ferlazzo, P. Forzatti, G. Busca, E. Giamello and F. Bregani, J. Catal, 1995, 155, 117.
W. G. Nilsen, Phys. Rev., 1969, 182, 838.
C. Falcony, M. Garcia, A. Ortiz and J. C. Alonso, J. Appl. Phys., 1992, 72, 1525.
W. Tang and D. C. Cameron, Thin Solid Films, 1996, 280, 221.
L. Jianhua, Y. Rong and L. Songmei, Rare Met., 2006, 25, 636.
J. M. Hermann, Top. Catal, 2005, 34, 49.
T. H. Lim, S. M. Jeong, S. D. Kim and J. Gyenis, React. Kinet. Catal. Lett, 2000, 71, 223.
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This paper is published as part of the themed issue of contributions from the 6th European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications held in Prague, Czech Republic, June 2010.
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Ciambelli, P., Sannino, D., Palma, V. et al. Intensification of gas-phase photoxidative dehydrogenation of ethanol to acetaldehyde by using phosphors as light carriers. Photochem Photobiol Sci 10, 414–418 (2011). https://doi.org/10.1039/c0pp00186d
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DOI: https://doi.org/10.1039/c0pp00186d