Synthesis of basic zeolite from coal fly ash and its reactivity in Knoevenagel reaction
DOI:
https://doi.org/10.11113/mjfas.v6n1.177Keywords:
coal fly ash, zeolites, ultrasonic treatment, Knoevenagel reaction, basic zeolite,Abstract
Zeolite was hydrothermally synthesized from coal fly ash in NaOH solution and static condition, at various times of crystallization and treatment. Gel
treated with ultrasonication before heating resulted in the formation of pure zeolite P (Na-P) while untreated gel formed a mixture of sodalite and Na-P. Pure zeolite P was produced in 5 days and stable up to 31 days of crystallization time without the trace of sodalite formed. The synthesized Na-P was then ion-exchanged with potassium (K-P) and cesium (Cs-P) ions in order to increase the basicity of the Na-P obtained. The reactivity of the catalysts was tested in Knoevenagel reaction between benzaldehyde and malononitrile, producing solid benzylidenemalononitrile as single product. The reactivity was measured by the time when the first solid product formed. K-P catalyst was found to be the most reactive followed by Cs-P and Na-P in which the reactivity depends more on the number of base sites as well as the basic strength of zeolite. In conclusion, zeolites synthesized from CFA is potential catalysts for the Knoevenagel reaction.
References
Keka,O., Narayan,C.P., Amar,N.S. Bull.of Mat.Sci, 27 (2004) 555-564
Querol,X. et al. Int. J. Coal Geology, 50 (2002) 413-423
Martin, W and Ulf, S. J. Brazil Chem. Society. 6 (1995) 393-403
Hollman, G.G., Steenbruggen, G., and Janssen-Jurkovicova, M., Fuel, 78 (1999) 1225-1230
Shamsul.K.,S. Solid State Science and Technology , 16 (2008) 107-113
Ono, Y. and Baba, T. Catalysis Today. 38 (1997) 321-337
Volcho.K.P et al. J. Molecular Catalysis A : Chemical. 195 (2003) 263-274
Lai,S.M. , Ng, C.P. , Rosa, M. ,King,L.Y. Microporous and Mesoporous Materials, 66 (2003) 239-252
Lau, W. N., Yeung, K. L., and Martin-Aranda, R. Microporous and Mesoporous Materials. 115 (2008) 156-163
Ganapati,V.S. , Minkee,C. , Jeongnam,K. , Ryong,R. J of Catalysis, 264 (2009) 88-92