BREEN, C. and WATSON, R. (1998). Acid-activated organoclays: preparation, characterisation and catalytic activity of polycation-treated bentonites. Applied Clay Science, 12 (6), 479-494.Full text not available from this repository.
Samples of SWy-2 and SAz-1 loaded with increasing amounts of the polycation magnafloc 206, [(Me2NCH2CHOHCH2)(n)]Cl-n+(n), were acid-treated using 6 M HCI at 95 degrees C for 30, 90 and 180 min. The activity of these acid-activated polycation-exchanged clays for the conversion of alpha-pinene to camphene and limonene was determined and compared with that from clay samples (without polycation) acid-treated in the same manner. Acid treatment of polycation-exchanged bentonites produced hybrid catalysts which enhanced the activity of the clays for the isomerisation of alpha-pinene to camphene and limonene. The presence of the polycation had a more marked influence on the activity of samples derived from SAz-1 increasing the yield from 25% for acid-activated SAz-1 with no added polycation to 50% camphene for acid-activated polycation-exchanged SAz-1. The increase in yield for corresponding samples derived from SWy-2 was only from 42 to 52%. This enhancement in yield for samples derived from SAz-1 was attributed to the increased hydrophobicity of the polycation loaded clay whilst the comparable yields for SWy-2 in the absence and presence of polycation may suggest that SWy-2 disperses well in the non-polar a-pinene. The total yields (based on alpha-pinene) for the most active catalysts was between 80 and 90%. These yields are directly comparable with those obtained by others using zeolites and pillared clays although the acid-activated polycation-treated clays were marginally less selective towards camphene. (C) 1998 Elsevier Science B.V.
|Research Institute, Centre or Group:||Materials and Engineering Research Institute > Polymers Nanocomposites and Modelling Research Centre > Polymers, Composites and Spectroscopy Group|
|Depositing User:||Jill Hazard|
|Date Deposited:||13 May 2010 09:46|
|Last Modified:||28 Sep 2010 17:12|
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