ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The reactors used for Selective Catalytic Reduction (SCR) of NOx require low pressuredrop structured catalyst packing. Structured packings, such as ceramic foams, are gaining increasinginterest for application in low pressure drop reactors, membrane reactors and catalytic distillationunits. In this work, cobalt ion exchanged mordenite (Co-HMOR)-coated cordierite-based foamsproduced by the replication method were evaluated for catalytic reduction of NOx with methane.The addition of 0.3 wt.% Pd to 2 wt.% Co-HMOR leads to a material that can convert 50 % NOx toN2 at 450 ºC in a reaction mixture containing 2000 ppm CH4, 1000 ppm NOx, 5 % O2 and balancehelium, at GHSV=17000 h-1. Although in an early stage of development, an efficient coatingprocedure was explored and different ways of exchange of Co and Pd cations into mordenite(Si/Al=10) were studied. Additions of 2 wt.% fumed silica enhanced adhesion of the zeolite ontothe ceramic foam. Pd-exchanged Co-HMOR showed to be very sensitive to steam. A 50 % decreasein NOx conversion to N2 was observed after Pd/Co-HMOR samples were exposed at 450 ºC to areaction mixture containing 2 vol% H2O. Although further research is needed to ascertain themechanism of this deactivation behaviour, agglomeration of Pd forming PdO particles is envisaged
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.587-588.810.pdf
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