Selective catalytic reduction of NO by NH3 over Fe2O3-promoted V2O5/TiO2-based catalysts with high Fe2O3-to-V2O5 ratios

Publication date: Available online 20 February 2020Source: Catalysis TodayAuthor(s): Thi Phuong Thao Nguyen, Ki Hyuck Yang, Moon Hyeon Kim, Yong Seok HongAbstractFe2O3-promoted V2O5-WO3/TiO2 catalysts with high Fe2O3-to-V2O5 ratios (3.4 – 6) have been prepared for the selective reduction of NO with NH3 (NH3-SCR) and extensively characterized using various spectroscopic measurements. No crystalline iron oxides were indicated even for 8% Fe2O3-promoted V2O5-WO3/TiO2 but distorted α-Fe2O3 crystallites were observed in a XRD pattern for 7.04% Fe2O3-promoted WO3/TiO2. Both Raman and XPS measurements suggest the formation of Fe-O-V species which may make a better N2 selectivity in NH3-SCR reaction at high temperatures. All Fe2O3-promoted catalysts showed a great depression on N2O formation. At temperatures> 400 °C, samples with 5.46 and 8% Fe2O3 (Fe2O3/V2O5 ratio = 3.4 and 5) gave significantly lower N2O production levels compared with the unpromoted and lower Fe2O3 loading catalysts. However, increasing in Fe2O3 loading resulted in a decrease in high temperature deNOx activity due to the oxidation of NH3 into NO. All the 3.4 and 5 ratio catalysts after a hydrothermal aging at 550 °C for 10 h gave NO removal activity and N2O formation similar to those measured over non-aged ones. However, such an aging at 750 °C could lead to a considerable increase in N2O formation even for the 5.46% Fe2O3-promoted catalyst. Fe2O3-promoted V2O5/TiO2-based catalysts could catalyze...

Source: Catalysis Today - February 21, 2020 Category: Chemistry Source Type: research