Study on the Mechanism of Catalytic Oxidation of NO with H2O2 Based on Fly-Ash-Derived Fe/ZSM-5 Catalysts

Solid waste fly ash can encroach on land, contaminate the environment, and jeopardize human health. An alkali fusion method combined with a hydrothermal method was adopted to prepare fly ash-derived ZSM-5 molecular sieves, and a series of Fe/ZSM-5 catalysts were also prepared to test their catalytic performance in NO oxidation with H2O2. Moreover, the characteristics of catalysts synthesized by fly ash, as well as the relationship between the structure and the catalytic activity, were analyzed in detail through multiple characterization approaches. The results gave important insights into the active sites of catalytic oxidation. They concluded that 10% Fe/ZSM-5 had the best catalytic activity in which Fe sites and Brønsted acid sites collectively provided the catalytic functionality, and 92% NO removal efficiency was obtained achieved under optimal experimental conditions. This work provided a new way for recycling fly ash and developing low-cost catalysts for NO removal.