High-temperature vanadium-free catalyst for selective catalytic reduction of NO with NH₃ and theoretical study of La₂O₃ over CeO₂/TiO₂

Abstract

High-temperature SCR catalyst of La2O3-CeO2/TiO2 was prepared by an impregnation method. The effect of CeO2 and La2O3 content on the NO conversion was studied and the experiment result showed that...

Insight on the anti-poisoning mechanism of in situ coupled sulfate over iron oxide catalysts in NOx reduction

“…[8][9][10] However, plenty of shortcomings such as inevitable biological toxicity, narrow active window, inferior low-temperature SCR activity, strong SO 2 oxidation ability, and poor resistance to alkali, alkaline earth, and heavy metal poisoning still exist and restrain the further application of vanadium-based catalysts. [11][12][13][14] Thus, it is still quite urgent to develop nonvanadium catalysts that can express better SCR activity and poisoning resistance that broaden the application potential. Among various kinds of metal oxide-based catalysts, Fe 2 O 3based catalysts possess environment-friendly characteristics, outstanding thermal stability, great N 2 selectivity, eminent mid-to-high SCR activity, and remarkable tolerance to SO 2 at high temperatures, which is a potential candidate that can be applied for the NH 3 -SCR reaction.…”

Preparation of high temperature NH3-SCR catalysts with carbonate as precursors by ball milling method

“…The catalyst prepared by the ball milling method using Ce(OH) 4 and La(OH) 3 instead of Ce 2 (CO 3 ) 3 and La 2 (CO 3 ) 3 as raw materials was denoted as BH-10Ce–2La/TiO 2 . The catalysts prepared by the impregnation method 7 and co-precipitation method 11 according to the literature were labeled as IN-10Ce–2La/TiO 2 and CN-10Ce–2La/TiO 2 , respectively.…”

“…3(c), the lower binding energy (529.5-530 eV) of O1s is attributed to lattice oxygen, denoted as O b ; the higher binding energy (531.4-531.8 eV) is attributed to surface unsaturated oxygen, denoted as O a ; and the highest peak (532-532.8 eV) corresponds to adsorbed water, denoted as O g . 7,10 Because O a has a higher mobility than the lattice oxygen O b , O a can lead to form more surface oxygen vacancies and subsequently be more highly active in oxidation reactions. As can be seen from Table 3, the O a concentration (76.92%) and O a /(O a + O b ) ratio (47.62%) of BC-10Ce-2La/TiO 2 are the highest among all catalysts, which is favorable for the oxidation of NO to NO 2 in the "fast SCR" mechanism.…”

“…In our previous report, we prepared a series of Ce–La/TiO 2 high-temperature NH 3 -SCR catalysts by the impregnation method. 7 The introduction of La 2 O 3 improved the catalytic activity and the Ce–La/TiO 2 catalysts had a wide temperature window (355–590 °C) and better catalytic performance than commercial vanadium-based catalysts at high temperature.…”

La and Co Addition to Mn/TiO2 Catalysts for Enhancing Low-Temperature Denitrification Activity and H2O/SO2 Tolerance

“…Doping or addition of other elements is a common way to improve the water and sulfur tolerance as well as the catalytic activity. Fan et al reported that a Mn-doped LaMnO 3 catalyst exhibited a long-term NO conversion of 95% along with high N 2 selectivity not affected by SO 2 and H 2 O. Wang et al found that La 3+ played a role in reducing the NH 3 and NO adsorption energies of CeO 2 /TiO 2 catalysts in the NH 3 –SCR reaction. Chen et al prepared manganese oxide (MnO x ) doped with several metals (Zr, Ni, and Co) by an impregnation method using biochar (BC) as the carrier.…”