Novel mesoporous SnCeVOx catalyst modified by amorphous titanium tungsten oxides for highly efficient NH3-SCR

Abstract

It is still difficult to create environment friendly, efficient and stable V-based catalysts for the selective catalytic reduction of NO_x with NH₃. In this work, amorphous titanium tungsten oxide (TiWO_y) modified mesoporous SnCeVO₄ (SnCeVO_x/TiWO_y) is reported as a promising alternative to address this issue. The as-prepared SnCeVO_x/TiWO_y exhibits excellent deNO_x activity with a wide active temperature window (>95% NO conversion at 195–430 °C) and high N₂ selectivity (>90% at 190–350 °C). Moreover, SnCeVO_x/TiWO_y delivers remarkable anti-poisoning durability to H₂O and SO₂, with negligible deNO_x activity loss at 215 °C after continuous reaction for 12 h in the presence of 200 ppm SO₂ and 5% H₂O. This excellent deNO_x performance is mainly attributed to the high specific surface area, strong surface acid properties, and rich oxygen vacancies, which benefits from introducing SnO₂ into CeVO₄ and further modification by TiWO_y. In situ DRIFTS spectra display that SnCeVO_x/TiWO_y follows both the L–H mechanism and E–R mechanism. This construction strategy provides a new insight for the development of efficient deNO_x catalysts with superior H₂O and SO₂ resistance.