Synthesis, Characterization and Catalytic Properties of Microporous Cobalt Aluminosilicate (CoLTL) Molecular Sieves

P. Selvam; S. Rajasekar

doi:10.18321/ectj397

Authors

P. Selvam National Centre for Catalysis Research, Department of Chemistry, Indian Institute of Technology-Madras, Chennai 600 036, India
S. Rajasekar National Centre for Catalysis Research, Department of Chemistry, Indian Institute of Technology-Madras, Chennai 600 036, India

DOI:

https://doi.org/10.18321/ectj397

Abstract

Thermally stable divalent cobalt substituted microporous aluminosilicate (CoLTL) molecular sieves were synthesized and characterized. These studies revealed isomorphous substitution of divalent cobalt in tetrahedral framework of LTL structure. In addition, the typical blue color of CoLTL confirms the tetrahedral environment of divalent cobalt in the framework, and as a result the catalyst showed excellent activity for the oxidation of cyclohexane under mild reaction conditions. Furthermore, unlike the many other cobaltbased microporous (heterogeneous) catalysts reported so far, CoLTL does not show any dislodgement or segregation of cobalt upon calcination or any other post-synthesis treatments. In this study, the performance of CoLTL was also compared with cobalt-containing aluminophosphate and silicate molecular sieves having AFI and MFI structures, respectively.

References

(1). Sheldon, R.A., and Kochi, J.K., Metal Catalysed Oxidation of Organic Compounds, Academic Press, New York, 1981. Crossref

(2). Lin, S.-S., and Weng, H.-S., Appl. Catal. A 105: 289 (1993). Crossref; 118:21 (1994).

(3). Vanoppen, D. L., De Vos, D.E., Genet, M.J., Rouxhet, P.G., and Jacobs, P.A., Angew. Chem. Int. Ed. Engl. 34:560 (1995). Crossref

(4). Thomas, J.M., Raja, R., Sankar, G., and Bell, R.G., Acc. Chem. Res. 34:191 (2001). Crossref

(5). Selvam P., and Mohapatra, S.K., J. Catal. 233: 276 (2005). Crossref

(6). Hamdy, M.S., Ramanathan, A., Maschmeyer, T., Hanefeld U., and Jansen, J.C., Chem. Eur. J. 12:1782 (2006). Crossref

(7). Hartmann M., and Kevan, L., Chem. Rev. 99: 635 (1999). Crossref

(8). Weckhuysen, B.M., Rao, R.R., Martens, J.A. and Schoonheydt, R.A., Eur. J. Inorg. Chem. 4:565 (1999). Crossref

(9). Montes, C., Montes, V.C., Villa A.L., and Corredores, N.M.R., Appl. Catal. A 197:151 (2000). Crossref

(10). Wan, Y., Williams, C.D., Duke C.V.A., and Cox, J.J., Micropor. Mesopor. Mater. 47:79 (2001). Crossref

(11). Sakthivel A., and Selvam, P., J. Catal. 211:134 (2002). Crossref

(12). Barrer R.M., and Villiger, H., Z. Kristallogr. 128:270 (1969). Crossref

(13). Jentys, A., Pham, N.H., Vinek, H., Englisch, M., Lercher, J.A., Micropor. Mater. 6:13 (1996). Crossref

(14). Weckhuysen, B.M., Verberckmoes, A.A., Uytterhoeven, M.G., Mabbs, F.E., Collison, D., Boer, E., Schoonheydt, R.A., J. Phys. Chem. B 104:37 (2000). Crossref

(15). Frache, A., Gianotti, E., Marchese, L., Catal. Today 77:371 (2003). Crossref