Green Chemistry and Technology

Biography

Biography: Yaxin Su

Abstract

Iron based catalysts supported on Aluminum Pillared Montmorillonite (Fe-Al-PILC) were prepared. The methods including XRD, H₂-TPR, Py-FTIR, Uv-Vis spectroscopy, ICP, N₂ adsorption-desorption, etc were used to characterize the basic physical and chemical properties of the catalysts. The characteristics of selective catalytic reduction of NO by propylene on the catalyst surface were studied experimentally in a fixed-bed reactor, and the effect of the Al³⁺/clay ratios on the physicochemical properties of the catalyst and the SCR-C₃H₆ was investigated. The results show that 9Fe/Al-PILC has higher SCR-C₃H₆ denitrification performance, e.g., 100% of NO conversion to N₂ was tested over 400 °C. The Al³⁺/clay ratio plays more important role on NO conversion than the calcination temperature of the carrier. According to the Al³⁺/clay ratios, the order of catalytic activity is 9Fe/Al-PILC-10 > 9Fe/Al-PILC-20 > 9Fe/Al-PILC-5 > 9Fe/clay > 9Fe/Al-PILC-40. Al³⁺ increased the specific surface area of the montmorillonite dramatically, and the catalyst had micropores and mesoporous structures. When the Al³⁺/clay ratio was 10 mmol/g, the pillared montmorillonite had the best physicochemical property. In the Fe/Al-PILC catalysts, the iron oxides are highly dispersed on the surface of the support. H₂-TPR shows that the reduction of Fe₂O₃ phase determines the SCR activity of the catalyst. With the increase of Al³⁺/clay ratio, the reducing temperature of the reducing process Fe₃O₄→Fe gradually increases. UV-vis results showed that Al³⁺ increased the oligomer FexOy, and the activity of the catalyst was positively correlated with the oligomer FexOy. Py-IR results showed that both Lewis acid and Bronsted acid were favorable for the selective catalytic reduction of NO. The 9Fe/Al-PILC-10 catalyst had the best activity, which was related to its higher Brønsted acid content.