Effect of various structure directing agents (SDAs) on low-temperature deactivation of Cu/SAPO-34 during NH3-SCR reaction
Journal article, 2018

Cu/SAPO-34 and Cu/SSZ-13 having chabazite structure (CHA) have attracted significant attention because of their high activity and N2selectivity during SCR reaction as well as superior resistance to hydrocarbon poisoning. Cu/SAPO-34 has shown better hydrothermal durability than Cu/SSZ-13 at high temperature. However, we have observed earlier that Cu/SAPO-34 prepared using morpholine as a structure directing agent (SDA) deteriorated under water exposure at low temperature, where the NOxconversion activity decreased from 87% to 6% after 9 h of low temperature exposure. In this study, Cu/SAPO-34 catalysts prepared using three different SDAs, i.e., morpholine (MO), triethylamine (TEA), and tetraethylammonium hydroxide (TEAOH), were prepared by the incipient wetness impregnation (IWI) method. A commercially purchased SAPO-34 (SAPO-34(ACS)) was also used for comparison purposes. After low temperature water deactivation, Cu/SAPO-34(TEA) and (TEAOH) mostly recovered their activities while Cu/SAPO-34(MO) and (ACS) only regained part of their activities after regeneration tests under a series of experimental conditions for the NH3-SCR reaction. Solid-state MAS NMR was employed to study the impact of SDAs on the coordination of Al, P, and Si in the SAPO-34 supports and Cu/SAPO-34 catalysts. CO-DRIFTS, NO-DRIFTS, and H2-TPR employed in this study collectively propose the presence of two different Cu locations in Cu/SAPO-34(MO, TEA, TEAOH, and ACS). It is suggested that the concentrations of Cu in two distinct locations within Cu/SAPO-34 catalysts characterized by CO-DRIFTS, NO-DRIFTS, and H2-TPR studies are significantly influenced by the choice of SDA, which will be important for understanding the deactivation mechanism of Cu/SAPO-34 catalysts during low temperature NH3-SCR reaction.


Jung Won Woo

Chemical Process and Reaction Engineering

Kirsten Leistner

Chemical Process and Reaction Engineering

Diana Bernin

Chemical Process and Reaction Engineering

Homayoun Ahari


Mark Shost


Michael Zammit


Louise Olsson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology

Competence Centre for Catalysis (KCK)

Catalysis Science and Technology

2044-4753 (ISSN) 2044-4761 (eISSN)

Vol. 8 12 3090-3106

Subject Categories

Inorganic Chemistry

Other Chemical Engineering

Organic Chemistry

Areas of Advance




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