%0 Journal Article
%T Insights over Titanium Modified FeMgOx Catalysts for Selective Catalytic Reduction of NOx with NH3: Influence of Precursors and Crystalline Structures
%J Catalysts | An Open Access Journal from MDPI
%D 2019
%R https://doi.org/10.3390/catal9060560
%X Titanium modified FeMgO x catalysts with different precursors were prepared by coprecipitation method with microwave thermal treatment. The iron precursor is a key factor affecting the surface active component. The catalyst using FeSO 4 and Mg(NO 3) 2 as precursors exhibited enhanced catalytic activity from 225 to 400 ¡ãC, with a maximum NO x conversion of 100%. Iron oxides existed as ¦Ã-Fe 2O 3 in this catalyst. They exhibited highly enriched surface active oxygen and surface acidity, which were favorable for low-temperature selective catalytic reduction (SCR) reaction. Besides, it showed advantage in surface area, spherical particle distribution and pores connectivity. Amorphous iron-magnesium-titanium mixed oxides were the main phase of the catalysts using Fe(NO 3) 3 as a precursor. This catalyst exhibited a narrow T 90 of 200/250¨C350 ¡ãC. Side reactions occurred after 300 ¡ãC producing NO x, which reduced the NO x conversion. The strong acid sites inhibited the side reactions, and thus improved the catalytic performance above 300 ¡ãC. The weak acid sites appeared below 200 ¡ãC, and had a great impact on the low-temperature catalytic performance. Nevertheless, amorphous iron-magnesium-titanium mixed oxides blocked the absorption and activation between NH 3 and the surface strong acid sites, which was strengthened on the ¦Ã-Fe 2O 3 surface. View Full-Tex
%U https://www.mdpi.com/2073-4344/9/6/560