Mechanism and Anaerobic Propan-1-ol Oxidation Reaction over Au/TiO2 Catalysts
[1]
Abdullahi Nuhu, Department of Pure and Applied Chemistry, Bayero University, Kano P. M. B 3011, Kano State, Nigeria.
[2]
Albert Carley, School of Chemistry, Cardiff University, Cardiff, CF10 3AT UK.
Our recent results concerning the propan -1-ol oxidation to propanal and other side products on gold based catalyst has motivated us to investigate and explore the anaerobic oxidation of propan -1- ol over Au/ TiO2 catalysts. In our study we found that gold on titania based catalyst are capable of converting propan –1-ol to propanal and other side products. It is suggested that the conversion of propan-1-ol to propanal by dehydrogenation and propene by dehydration by gold on TiO2 catalyst prepared by deposition precipitation. The adsorption of propan-1-ol over TiO2 (P25) indicated a full monolayer with much of it in a dissociated state, forming propoxy group on the cationic site and hydroxyl group at anions. The propoxy is relatively stable until about 250oC, at which dehydration to propene occurs by bimolecular surface reaction. As the concentration of propoxy on the surface disappear, so mechanism reverts to a decomposition pathway, producing CO2 and H2O. However, the presence of gold on the catalyst is marked with complete conversion of propan-1-ol at low temperature (230oC) lower than Titania (300oC).
[1]
M. Haruta, Catal. Today 36 (1997) 153
[2]
M. Bowker, A. Nuhu, and J. Soares, Catalysis Today, 122 245-247 (2007)
[3]
A. Nuhu Bayero Journal of Physical and Applied Sciences (BAJOPAS) 23 134-139 (2009)
[4]
J. Arana. J. M. Dona- Rodrigues, J. A. Herrera Melian, E. Tello Rendon, O. Gonzalez Diaz, J. of PhotoChem. And Photobio. A: Chemistry 174 7-14(2005)
[5]
J. E.Baile, C. H. Rochester and G. Hutchings, J. of Chem. Soc., Faraday Trans., 93 4389-4394 (1997)
[6]
T. A. Nijhuis, T. Visser and B. M.. Weckhysen, Angew. Chem. Int. Ed. 44 1115-1118 (2005)
[7]
T. Kecskes, J.Rasko and J. Kiss, Appl. Catal. A: Gen. 273 55-62 (2004).
[8]
A. V. Vorontsov and V. P. Dubovitskaya, Journal of Catalysis 221102-109 (2004).
[9]
F. G. Montanez, Z. Yu, S. S.Chuang and Chen Yang,
[10]
Gamal. A. M. Hussein and N. Sheppard. M.I. Zaki and R. B. Fahim, J. Chem. Soc. Faraday Trans., 87(16), 2661-2668 (1991)
[11]
H. Idriss, Platinum Metal Rev, 48(3), 105-115 (2004)
[12]
J. Rasko, M. Domok, K. Baan and A. Erdohelyi, App. Cat. A: Gen. 299 202-211 (2006)
[13]
A. Erdohelyi, J. Rasko, T. Kecskes, M. Toth, Marta Domok, and K. Baan, Cat. Today 116 367-376 (2006)
[14]
J.M.Guil, N. Homs, J. Llorca, and P. Ramirez de la Piscina, J. Phys. Chem. B. 109 10813-10819 (2005)
[15]
R. Hayashi, M. Onishi, M. Sugiyama, S. Koda, and Y. Oshima, J. of supercritical Fliuds 40 74-83 (2007)
[16]
J. Arana. J. M. Dona- Rodrigues, J. A. Herrera Melian, E. Tello Rendon, O. Gonzalez Diaz, J. of PhotoChem. And Photobio. A: Chemistry 174 7-14 (2005)
[17]
T. A. Egerton, and J. A. Mattinson, J. J. of PhotoChem. And Photobio. A: Chemistry 186 115-120 (2007)
[18]
A. E. Mucients, F. J. Poblete, M. A. Rodriguez and F. Santiago, J. of Phys. Org. Chem, 10 662-668 (1997)
[19]
J. E.Baile, C. H. Rochester and G. Hutchings, J. of Chem. Soc., Faraday Trans., 93 4389-4394. (1997)
[20]
Z. Yu, S.C. S. Chuang, Journal of Catalysis 246 118-126 (2007).
[21]
L.Parti and F. Porta, Appl. Catal. A: Gen. 291 199 (2005).
[22]
S. Biella and M. Rossi, Chem, Commun. 378 (2003).
[23]
M.A. Centeno, M. Paulis, M. Montes and J. A. Odriozola, Appl. Catal. A: Gen. 234 65 (2002).
