202
S. Gil et al. / Applied Catalysis A: General 450 (2013) 189–203
production process (note that in the present work, the same purifi-
cation processes as those used by the biodiesel production industry
were used [46]).
[3] A. Nieto-Márquez, S. Gil, A. Romero, J.L. Valverde, S. Gómez-Quero, M.A. Keane,
Appl. Catal. A 363 (2009) 188–198.
[4] C.D. Taboada, J. Batista, A. Pintar, J. Levec, Appl. Catal. B 89 (2009) 375–382.
[5] G.L. Bezemer, P.B. Radstake, V. Koot, A.J. van Dillen, J.W. Geus, K.P. de Jong, J.
Catal. 237 (2006) 291–302.
[6] C. Liang, Z. Li, J. Qiu, C. Li, J. Catal. 211 (2002) 278–282.
[7] K.P. de Jong, J.W. Geus, Catal. Rev.: Sci. Eng. 42 (2000) 481–510.
[8] C. Amorim, G. Yuan, P.M. Patterson, M.A. Keane, J. Catal. 234 (2005) 268–281.
[9] A. Nieto-Márquez, M.A. Keane, J.L. Valverde, Appl. Catal. A: Gen. 332 (2007)
237–246.
[10] Z.C. Kang, Z.L. Wang, J. Mol. Catal. A: Chem. 118 (1997) 215–222.
[11] J. Bedia, J.M. Rosas, J. Rodríguez-Mirasol, T. Cordero, Appl. Catal. B 9 (2010)
8–18.
[12] S. Demirel-Gülen, M. Lucas, P. Claus, Catal. Today 102 (2005) 166–172.
[13] K. Tanaka, M. Shou, Y. Yuan, J. Phys. Chem. 114 (2010) 16917–16923.
[14] F. Porta, L. Prati, M. Rossi, G. Scari, J. Catal. 211 (2002) 464–469.
[15] F. Porta, M. Rossi, J. Mol. Catal. A: Chem. 204 (2003) 553–559.
[16] L. Prati, M. Rossi, J. Catal. 176 (1998) 552–560.
[17] S. Biella, L. Prati, M. Rossi, J. Catal. 206 (2002) 242–247.
[18] P. Serp, R. Feurer, Y. Kihn, P. Kalck, J.L. Faria, J.L. Figueiredo, J. Mater. Chem. 11
(2001) 1980–1981.
On the other hand, methyl esters, formed in the saponifica-
tion process that takes place during the transesterification of fatty
oils, could not be eliminated by any of the above commented
production-side reaction where methyl esters and/or triglyceride,
diglyceride and monoglyceride react with hydroxyl anions to form
production reaction yield [88]. In order to reduce the impact of the
saponification reaction, CH3ONa is often used as a catalyst for the
transesterification of fatty oils [46], since its use allows to decrease
the concentration of these impurities, produced to the saponifica-
tion process [89,90].
[19] A. Nieto-Márquez, D. Toledano, P. Sánchez, A. Romero, J.L. Valverde, J. Catal. 269
(2010) 242–251.
4. Conclusions
[20] M. Mittelbach, C. Remschmidt, Biodiesel: The Comprehensive Handbook,
Boersedruck Ges M.B.H., Vienna, 2004.
[21] M. McCoy, Chem. Eng. News 84 (2006) 23.
[22] K.T. Tan, K.T. Lee, A.R. Mohamed, Fuel 89 (2010) 3833–3839.
[23] M.-I. Galan, J. Bonet, R. Sire, J.-M. Reneaume, A.E. Ples, Bioresour. Technol. 100
(2009) 3775–3778.
[24] S. Carrettin, P. McMorn, P. Johnston, K. Griffin, G.J. Hutchings, Chem. Commun.
(2002) 696–697.
From our investigation about the liquid phase selective glycerol
oxidation arises that the nature of the support strongly influ-
ences the catalyst properties. Obtained results show that the Au
particle size decreases with the graphitic character. Furthermore,
comparing the catalytic behavior of different Au/C catalysts (with
different gold particles sizes), it could be shown that the glycerol
oxidation is structure-sensitive. Catalyst Au/G resulted in a higher
catalytic activity than that obtained with the catalyst Au/CNF-R.
However, the CNS-based catalyst resulted to be more active, which
was attributed to the higher dispersion of Au particles as a con-
sequence of the presence of many open edges at the surface, that
allow to a high chemical reactivity. In fact, the selectivity to glyc-
eric acid was not affected with the gold particle size (Au/CNS,
dAu = 4.2 nm). Consequently, the metal particle size of the Au/C cat-
alyst plays a major role in the oxidation of glycerol. On the other
hand, catalytic activity was considerably decreased when using
crude glycerol as the feedstock due to the presence of impuri-
ties (mainly CH3ONa and methyl esters), producing the important
changes in the surfaces properties of the support and the leaching of
gold into the liquid reaction solution. Nevertheless, after a low cost
crude glycerol purification treatment (neutralization of the previ-
ously evaporated crude glycerol using hydrochloric acid), very good
catalytic results were obtained (similar to those obtained using
the commercial glycerol as the feedstock). As final conclusion it is
important to note that, process using unrefined glycerol involved
to animal feed, co-digestion/co-gasification, and waste treatment,
have potential to be adopted in the short term. Nevertheless, in
the medium and long term these alternatives should be replaced
with alternatives that could provide more value-added products
with low environmental impact similar to the process and product
studied in this work (production of chemical products, polymers,
fuel additives, hydrogen production and development of fuel cells)
[91].
[25] Ch.-H. Zhou, J.N. Beltramini, Y.-X. Fana, G.Q. Lu, Chem. Soc. Rev. 37 (2008)
527–549.
[26] N. Dimitratos, J.A. Lopez-Sanchez, G.J. Hutchings, Top. Catal. 52 (2009) 258–268.
[27] L. Prati, P. Spontoni, A. Gaiassi, Top. Catal. 52 (2009) 288–296.
[28] S.D. Pollington, D.I. Enache, P. Landon, S. Meenakshisundaram, N. Dimitratos,
A. Wafland, G.J. Hutchings, E.H. Stitt, Catal. Today 145 (2008) 169–175.
[29] G.-J. Ten Brink, I.W.C.E. Arends, R.A. Sheldon, Science 287 (2000) 1636–1639.
[30] J.C. Yori, S.A. D’Ippolito, C.L. Pieck, C.R. Vera, Energy Fuels 21 (2007) 347–353.
[31] C.W. Chiu, M.J. Goff, G.J. Suppes, AIChE J. 51 (2005) 1274–1278.
[32] L. Bournay, D. Casanave, B. Delfort, G. Hillion, J.A. Chodorge, Catal. Today 106
(2005) 190–192.
[33] M. Di Serio, R. Tesser, M. Dimiccoli, F. Cammarota, M. Nastasi, E. Santacesaria,
J. Mol. Catal. A: Chem. 239 (2005) 111–115.
[34] S. Gil, L. Mun˜oz, L. Sánchez-Silva, A. Romero, J.L. Valverde, Chem. Eng. J. 172
(2011) 418–429.
[35] S. Gil, M. Marchena, L. Sánchez-Silva, P. Sánchez, A. Romero, J.L. Valverde, Chem.
Eng. J. 178 (2011) 423–435.
[36] S. Carrettin, P. McMorn, P. Johnston, K. Griffin, G.J. Hutchings, C.J. Kielly, Phys.
Chem. 5 (2003) 1329–1336.
[37] W.C. Ketchie, M. Murayama, R.J. Davis, Top. Catal. 44 (2007) 307–317.
[38] G.J. Hutchings, S. Carrettin, P. Landon, J.K. Edwards, D. Enache, D.W. Knight, Y.-J.
Xu, A.F. Carley, Top. Catal. 38 (2006) 223–230.
[39] V. Jiménez, A. Nieto-Márquez, J.A. Díaz, R. Romero, P. Sánchez, J.L. Valverde, A.
Romero, Ind. Eng. Chem. Res. 48 (2009) 8407–8417.
[40] L. Prati, F. Porta, Appl. Catal. A: Gen. 291 (2005) 199–203.
[41] F. Porta, L. Prati, M. Rossi, S. Coluccia, G. Martra, Catal. Today 61 (2000) 165–172.
[42] S. Biella, F. Porta, L. Prati, M. Rossi, Catal. Lett. 90 (2003) 1–2.
[43] J.D. Grunwaldt, C. Kiener, C. Wögerbauer, A. Baiker, J. Catal. 181 (1999) 223–232.
[44] I. Sobczak, K. Jagodzinska, M. Ziolek, Catal. Today 158 (2010) 121–129.
[45] F. Wang, G. Lu, Catal. Lett. 115 (2007) 46–51.
[46] M.J. Ramos, C.M. Fernández, A. Casas, L. Rodríguez, Á. Pérez, Bioresour. Technol.
100 (2009) 261–268.
[47] A. Casas, C.M. Fernández, M.J. Ramos, Á. Pérez, J.F. Rodríguez, Fuel 89 (2010)
650–658.
[48] J.R. Anderson, Structure of Metallic Catalysts, Academic Press, New York, Lon-
don, 1975, p. 296.
[49] C. Amorim, M.A. Keane, J. Chem. Technol. Biotechnol. 83 (2008) 662–672.
[50] K.S.W. Sing, D.H. Everett, R.A.W. Haul, L. Moscou, R.A. Pierotti, J. Rouquerol, T.
Siemieniewska, Pure Appl. Chem. 57 (1985) 603–619.
Acknowledgements
[51] P. Serp, R. Feurer, Ph. Kalck, Y. Kihn, J.L. Faria, J.L. Figueiredo, Carbon 39 (2001)
621–626.
[52] Z.L. Wang, Z.C. Kang, Carbon 35 (1997) 419–426.
[53] C. Park, M.A. Keane, J. Catal. 221 (2004) 386–399.
[54] D. Bom, R. Andrews, D. Jacques, J. Anthony, B. Chen, M.S. Meier, J.P. Selegue,
Nano Lett. 2 (2002) 615–619.
[55] Z. Yu, D. Chem, M. Ronning, B. Totdal, T. Vralstad, E. Ochoa-Fernández, A. Hol-
men, Appl. Catal. 338 (2008) 147–158.
The authors gratefully acknowledge financial support from the
Regional Government of Castilla-La Mancha (Project PCI08-0020-
1239). Prof. Anne Giroir-Fendler and Laurence Massin (Université
Claude Bernard Lyon 1, France (IRCELYON)) are gratefully acknowl-
edged for assistance in XPS measurements and for stimulating
discussions.
[56] A. Romero, A. Garrido, A. Nieto-Márquez, A. de la Osa, A. de Lucas, J.L. Valverde,
Appl. Catal. A: Gen. 319 (2007) 246–258.
[57] A. Romero, A. Garrido, A. Nieto-Márquez, P. Sánchez, A. de Lucas, J.L. Valverde,
Micropor. Mesopor. Matter 110 (2008) 318–329.
References
[58] S. Choi, K.H. Park, S. Lee, K.H. Koh, J. Appl. Phys. 92 (2002) 4007.
[59] M.S. Dresselhaus, G. Dresselhaus, R. Saito, A. Jorio, Phys. Rep. 409 (2005) 47–99.
[60] F. Tuinstra, J.L. Koenig, J. Chem. Phys. 53 (1970) 1280–1281.
[61] R.J. Nemanich, S.A. Solin, Phys. Rev. B 20 (1979) 392–401.
[1] P. Serp, M. Corrias, P. Kalck, Appl. Catal. A 253 (2003) 337–358.
[2] F. Rodríguez-Reinoso, Carbon 36 (1998) 159–175.