Chemical deactivation of H-BEA and Fe-BEA as NH3-SCR catalysts - Effect of potassium
Journal article, 2015

H-BEA and Fe-BEA were experimentally studied for selective catalytic reduction of NOx using ammonia (NH3-SCR) with focus on the chemical deactivation caused by potassium exposure where cordierite supported H-BEA and Fe-BEA samples were exposed to 10 or 50 ppm KNO3 for 14, 24 and 48 h in a continuous gas flow reactor at 3500C. The samples where catalytically evaluated and characterized using a flow-reactor system and X-ray photoelectron spectroscopy. The results show that new NOX storage sites are formed on the expense of Brønsted acid sites for ammonia storage for all potassium exposed samples. The formation of new NOX storage sites results in increased NH3-SCR activity for the potassium exposed H-BEA samples. However, for the potassium exposed Fe-BEA samples the results show a significant decrease in SCR activity. Deconvolution of the Fe 2p3/2 XPS peak shows a clear increase in the relative amount of Fe3+ for the potassium exposed Fe-BEA samples, indicating that isolated iron species active for NH3-SCR are exchanged with potassium forming smaller trivalent iron clusters inside the zeolite pores. Transient experiments during NH3-SCR show that the decrease in ammonia storage capacity due to potassium exposure results in a decreased period with improved NO reduction after NH3 cut-off.

Potassium

NOx adsorption

Fe-BEA

Chemical deactivation

NH3-SCR

XPS

Author

Soran Shwan

Competence Centre for Catalysis (KCK)

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Jonas Jansson

Volvo Group

Louise Olsson

Competence Centre for Catalysis (KCK)

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Reaction Engineering

Magnus Skoglundh

Competence Centre for Catalysis (KCK)

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Applied Catalysis B: Environmental

0926-3373 (ISSN) 1873-3883 (eISSN)

Vol. 166-167 277-286

Driving Forces

Sustainable development

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Transport

Energy

Materials Science

Subject Categories

Physical Chemistry

Chemical Process Engineering

Materials Chemistry

DOI

10.1016/j.apcatb.2014.11.042

More information

Latest update

11/16/2018