A Greener Route for Synthesis of Fly Ash Supported Heterogeneous Acid Catalyst

Abstract

Fly ash, a solid by-product obtained from coal-fired thermal power plants, is basically a silico-aluminate material having varying minor amounts of other metal oxides. For suitable bulk utilization of this solid waste, a novel kind of solid acid catalyst has been successfully synthesized by employing microwave assisted greener route. For enhancing the efficacy, amorphous silica was extracted from fly ash in a cost-effective manner which was further chemically activated with H2SO4. Various analytical techniques were utilized to study physico-chemical properties of the as-prepared catalyst, while the catalytic activity was tested by a serious of microwave assisted esterification and Friedel-Crafts alkylation reactions under optimized reaction conditions. Higher yield of products attributes to the presence of significant number of Bronsted acidic sites on catalyst, also proved by Pyridine adsorbed FT-IR spectrum of catalyst. The catalyst was recovered and reused up to five reaction cycles with similar competence as in first run which deliberates its stability during the course of reaction