Research on Performance and Mechanism of the NH3-SCR Reaction over Fly Ash-derived Mn-Ce/Zeolite X

Zeolite X was synthesized from fly ash under optimized conditions, which supported with Mn, Ce, and Mn-Ce respectively. Fly ash-derived zeolite catalysts exhibited similar catalytic performance as compared the commercial catalyst. XRD, N2 adsorption, SEM, XPS, H2-TPR were used to investigate relationship among structure, physicochemical properties, activities of catalysts. Finally, mechanism NH3-SCR reaction on Mn-Ce/zeolite systematically performed by using diffused reflectance infrared Fourier transform spectroscopy (DRIFTS). The characterization results showed that amorphous structure good dispersion between Mn Ce surface changed electronic properties active components, improved its low-temperature activity, brought it characteristics at same time, broaden temperature range. NO conversion rate Mn-Ce-FX catalyst remained above 80% 200℃~300℃. From DRIFTS we suggest Eley-Rideal Langmuir-Hinshelwood are simultaneously carried out surface. According FTIR results, has a great influence below 250℃, Brønsted acid sites adsorb large amount NH3, resulting in an excellent activity. When plays dominant role. nitrates gradually convert bidentate nitrates, impeding SCR reaction, could be one reasons for reducing high-temperature