Ceria–tungsten–tin oxide catalysts with superior regeneration capacity after sulfur poisoning for NH₃-SCR process

Abstract

Nowadays, there exists a trade-off between high-temperature thermal stability and low-temperature catalytic activity for metal oxide catalysts for the NH3-SCR reaction, which restricts the practical application of metal oxide catalysts...

A Study of CeSnOx and Pd/CeSnOx as Low-Temperature NOx Adsorbers with Excellent Hydrothermal Stability

“…The XPS Ce 3d spectra are shown in Figure a. The peaks noted μ′ and υ′ are attributed to Ce 3+ and those noted μ, υ, μ″, υ″, μ‴, and υ‴ are related to Ce 4+ . − The proportion of Ce 3+ /Ce is shown in Figure a. Ce 3+ /Ce was increased for CeSnO x -F by loading Pd and increased with the increase of Pd loading, which indicated that the addition of Pd increased the redox ability .…”

Research on structural strengthening technology for regenerative denitration catalysts

“…9,10 Long-term operation at high temperatures can easily cause clogging and sintering of vanadium and titanium SCR catalysts, thus severely wearing the catalyst surface and further degrading the catalyst strength. 11 Regeneration techniques for deactivated SCR catalysts include water-wash regeneration, 12,13 thermal reduction regeneration, 14,15 acid (alkali)-wash regeneration, 12,16 and compound regeneration. 5,17,18 Regeneration is also subject to ultrasonic cleaning, which leads to wear and tear of the catalyst surface and a reduction in the compressive strength, thereby affecting the performance of the regenerated SCR catalyst.…”

“…Many current studies on improving the mechanical properties of catalysts have focused on the mechanical strength of industrial catalysts during molding, and few studies have focused on improving the mechanical properties of the molded or regenerated catalysts. 5,12,13,19 However, the regenerated catalysts must satisfy the mechanical strength requirements of GB/T 31587-2015 (compressive strength Z2.0 Mpa, wear rate r0.1% kg À1 ). Researchers [13][14][15][20][21][22][23] conducted regeneration experiments on SCR catalysts using a microwave-ethanol solution and found that a microwave-ethanol solution not only increased the specific surface area of denitration catalysts but also improved their mechanical properties.…”

“…5,12,13,19 However, the regenerated catalysts must satisfy the mechanical strength requirements of GB/T 31587-2015 (compressive strength Z2.0 Mpa, wear rate r0.1% kg À1 ). Researchers [13][14][15][20][21][22][23] conducted regeneration experiments on SCR catalysts using a microwave-ethanol solution and found that a microwave-ethanol solution not only increased the specific surface area of denitration catalysts but also improved their mechanical properties. However, the compressive strength of the catalysts increased only by 1.612 MPa after three reaming cycles, because of the absence of a structural strengthening process, and could not meet practical requirements.…”