1. Introduction2. Coal fly ash hazards3. Coal fly ash applications4. Coal fly ash as a catalyst5. Characterization of catalysts5.1. Mineralogy5.2. Morphology6. Effective parameters in catalytic reactions6.1. Effects of reaction time6.2. Effects of reaction temperature6.3. Effects of catalysts loading and molar ratio7. Kinetic and isotherm studies8. Performance of CFA catalysts8.1. Degradation of aqueous and gaseous pollutants by CFA catalysts8.1.1. Dyes degradation8.1.2. Phenol derivatives degradation8.1.3. Pollutant degradation by CFA-based photocatalysts8.1.4. Capturing gaseous pollutants8.2. Chemical conversion reactions by CFA catalysts8.2.1. Oxidation reactions8.2.2. Esterification and trans-esterification reactions8.2.3. Condensation reactions8.2.4. Acylation reactions8.2.5. Glycerol hydrogenolysis reaction8.2.6. Other reactions8.3. Synthesis of chemical materials9. ConclusionsReferences