Journal article
Sulfur poisoning and regeneration of the Ag/γ-Al2O3 catalyst for H2-assisted SCR of NOx by ammonia
Department of Physics, Technical University of Denmark1
Computational Atomic-scale Materials Design, Department of Physics, Technical University of Denmark2
SLAC National Accelerator Laboratory3
Surface Physics and Catalysis, Department of Physics, Technical University of Denmark4
Haldor Topsoe AS5
Sulfur poisoning and regeneration mechanisms for a 2% Ag/γ-Al2O3 catalyst for the H2-assisted selective catalytic reduction of NOx by NH3 are investigated. The catalyst has medium sulfur tolerance at low temperatures, however a good capability of regeneration at 670°C under lean conditions when H2 is present.
These heating conditions can easily be established during soot filter regeneration. Furthermore, two types of active sites could be identified with different regeneration capabilities, namely finely dispersed Ag and larger Ag nanoparticles. The most active sites are associated with the finely dispersed Ag.
These sites are irreversibly poisoned and cannot be regenerated under driving conditions. On the other hand the larger Ag nanoparticles are reversibly poisoned by direct SOx adsorption. The interpretation of the data is supported by DFT calculations.
Language: | English |
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Year: | 2012 |
Pages: | 49-58 |
ISSN: | 18733883 and 09263373 |
Types: | Journal article |
DOI: | 10.1016/j.apcatb.2012.01.002 |