Effect of acid leaching on the denitrification efficiency of a MnCe@FA catalyst derived from fly ash: structure, crystal phase, active component interaction phase and active components

The development of low-cost and highly active denitrification catalyst systems is of significant importance for the sustainable management of air pollution. In this study, a MnCe@FA catalyst was prepared using fly ash (FA) as the support and was utilized for the removal of NO. The acid leaching of fly ash allows for the regulation of SiO₂ crystal faces, while also enhancing the pore structure of the catalyst, achieving an increase in the average pore diameter by up to 26%. Moreover, the proportion of surface Ce⁴⁺, Mn³⁺, and O_β in the catalyst derived from acid-treated fly ash showed a marked enhancement. At 200 °C, this catalyst demonstrated an NO removal efficiency of 84%. The denitrification reaction occurs as NO adsorbs onto the catalyst surface, forming -NO₂, which subsequently reacts with NH₃ species, following the Langmuir-Hinshelwood mechanism. This research provides meaningful insights into the comprehensive utilization of fly ash and the development of low-temperature denitrification catalysts.