Impact of Different Synthesis Methods on the Low-Temperature Deactivation of Cu/SAPO-34 for NH3-SCR Reaction

• Published in: Emission control science and technology (Online) Vol. 7; no. 3; pp. 198 - 209
• Main Authors: Woo, Jungwon, Wang, Aiyong, Bernin, Diana, Ahari, Homayoun, Shost, Mark, Zammit, Michael, Olsson, Louise
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-09-2021; Springer Nature B.V
• Subjects: Ammonia; Catalysts; Chemical synthesis; Copper; Deactivation; Earth and Environmental Science; Earth Sciences; Environmental Science and Engineering; Experiments; Geographical distribution; Industrial Chemistry/Chemical Engineering; Ion exchange; Low temperature; Methods; Morpholine; NMR; Nuclear magnetic resonance; Regeneration; Solid state; Surfaces and Interfaces; Temperature; Temperature tolerance; Tetraethylammonium; Thin Films; Triethylamine; Water vapor; Zeolites; Low-temperature deactivation; SCR, Cu/SAPO-34; NH; Different SDAs; Synthesis methods
• ISSN: 2199-3629; 2199-3637
• DOI: 10.1007/s40825-020-00182-y

SAPO-34 were synthesized using three structure-directing agents (SDAs), i.e., tetraethylammonium hydroxide (TEAOH), triethylamine (TEA), and morpholine (MO). These SAPO-34 supports were used to prepare Cu/SAPO-34 catalysts via two different Cu-exchange methods: incipient wetness impregnation (IWI) and solid-state ion exchange (SSIE). The catalytic performance of Cu/SAPO-34(TEAOH, TEA, MO) catalysts prepared with IWI and SSIE before and after exposure to water vapor at 70 °C was systemically examined, and their deactivation behavior during low-temperature NH
3
-SCR reaction was studied. These catalysts were characterized by XRD, BET, ICP-SFMS, SEM/EDX, solid-state NMR, CO-DRIFTS, NO-DRIFTS, and H
2
-TPR. The various characterization findings for the Cu/SAPO-34 catalysts suggest that the distribution of different Cu
2+
species and the mobility of Cu
2+
in chabazite (CHA) structure are important for the low-temperature deactivation and regeneration behaviors of the Cu/SAPO-34(TEAOH, TEA, MO)-IWI and -SSIE during the NH
3
-SCR reaction. Thus, it has been determined that the choice of SDA and Cu-exchange method is vital to design of an efficient Cu/SAPO-34 catalyst that is highly active during a NH
3
-SCR reaction and has a high tolerance for the low-temperature deactivation caused by exposure to water vapor.