Co-catalytic effect of Al-Cr pillared montmorillonite as a new SCR catalytic support

Abstract

BACKGROUND It is of great interest to use pillared clay (PILC) as a cheap support for a selective catalytic reduction (SCR) catalyst. Al‐Cr pillared clay (AlCr‐PILC) has high thermal stability due to the introduction of polycations of Al. As a support, AlCr‐PILC may show a co‐catalytic effect in SCR processes because chromium oxide itself is an active SCR catalyst. The aim of this work is to investigate the potential of AlCr‐PILC as a new low temperature SCR catalyst support. RESULTS A series of AlCr‐PILC with Al:Cr molar ratio varying from 0:4 to 4:0 were successfully synthesized to support manganese and cerium active phase. MnCe/AlCr(2:2)‐PILC exhibited the highest NOx conversion close to 100% at 200–300 °C, and more than 90% N2 selectively over a wide temperature window of 140–300 °C. The catalytic activity of MnCe/AlCr‐PILC in terms of both NOx conversion and N2 selectivity is much higher than those of MnCe/Al‐PILC, MnCe/Cr‐PILC, AlCr‐PILC, and the simple mixed MnCeAlCr, indicating the co‐catalytic effect of AlCr‐PILC support. CONCLUSION AlCr‐PILC is a very promising low‐temperature SCR catalyst support. The XRD, XPS, and H2‐TPR measurements prove that the co‐catalytic effect of AlCr‐PILC occurred via the strong interaction between MnCe and the AlCr‐PILC support. © 2016 Society of Chemical Industry

Low Temperature Selective Catalytic Reduction (SCR) of NOx Emissions by Mn-doped Cu/Al2O3 Catalysts

“…The observed binding energies 644.8 eV, and 653.85 eV are associated with the presence of Mn 2+ and Mn 3+ respectively in their respective samples [36,37]. BE of Al-2p is shown at 74.6 eV revealed Al 3+ oxidation state as shown in Figure 2(c).…”

Molybdenum modified Montmonrillonite clay as an efficient catalyst for low temperature NH3‐SCR

“…The Al‐, Zr‐, AlZr‐intercalations: as described in our previous report, the Al and/or Zr pillaring solution was synthesized by adding a 1 M Na 2 CO 3 (100 mL) solution into a solution of AlCl 3 and/or ZrOCl 2 under continuously stirring at 60 °C for 2 h, and aged for 24 h at room temperature. The optimized molar ratio of Al to Zr in the AlZr co‐pillaring solution was 1:1.…”

“…The commercial Vanadium‐based NH 3 ‐SCR catalyst, such as V 2 O 5 ‐WO 3 (MoO 3 )/TiO 2 , operates in a narrow reaction temperature window of 300–400 °C, hence, the SCR catalyst units need to be installed in the upstream of the desulfurizers and dust removal devices. However, this setup can cause some problems, such as the oxidation of SO 2 to SO 3 , corrosion of the downstream devices and the deactivation of catalysts due to dust and alkali metals deposition . Therefore, a NH 3 ‐SCR catalyst that works at temperature lower than 300 °C is highly desired.…”

“…However, this setup can cause some problems, such as the oxidation of SO 2 to SO 3 , corrosion of the downstream devices and the deactivation of catalysts due to dust and alkali metals deposition. [4][5][6][7] Therefore, a NH 3 -SCR catalyst that works at temperature lower than 300°C is highly desired.…”

Selective catalytic reduction of NOx with NH3 over iron‐cerium mixed oxide catalyst prepared by different methods

“…Selective catalytic reduction (SCR) is the most critical technology to control the emission of nitrogen oxides [NO x , mainly nitric oxide (NO)], which has been widely used in chimney exhaust of thermal power plants and incineration plants, as well as motor vehicle exhaust fueled by diesel oil. The technology uses ammonia (NH 3 ) as reducing agent that is produced by urea, ammonia water or liquid ammonia, and the principal is to prepare denitration catalysts with good selectivity, high selectivity and high strength . At present, the most commonly used catalysts in industry are vanadium (V)‐based catalysts including V 2 O 5 ‐WO 3 /TiO 2 and MoO 3 ‐V 2 O 5 /TiO 2 .…”