Anita Sharma, Vijay Devra and Ashu Rani
This study investigated the chemical modifications of coal fly ash treated with concentrated HClO4. A solid acid catalyst PAFA was synthesized by the chemical treatment which was prepared from Perchloric acid activation. The physico-chemical modifications of PAFA catalyst was investigated by employing various analytical techniques such as XRF, XRD, FT-IR, SEM and BET surface area. The Brønsted and Lewis acidity of the catalysts were measured by pyridine adsorbed FT-IR. The catalytic performance of PAFA catalyst was evaluated for the series of esterificationt reaction viz. esterification of acetic acid and various alcohols (such as ethanol, propanol, n-butanol, isoamyl alcohol, octanol and benzyl alcohol) to give ester, which are an important fine chemical intermediate, widely used in pharmaceutical and as flavoring agent in confectionary. The catalyst was completely recyclable without significant loss in activity up to 4 reaction cycles, which confers its stability during reaction. The work reports an innovative use of solid waste fly ash as an effective solid acid catalyst.