“…The catalytic properties can be improved by different acid treatment and/or pillaring methods (Auer and Hofmann, 1993;Ravichandran et al, 1996;Upadhya et al, 1996;Chitnis and Sharma, 1997;Clark et al, 1997). For example, the alkylation of many organic compounds, including phenols, aromatics, and other hydrocarbons, is catalyzed by acid-treated clays (Chitnis and Sharma, 1997).…”