fulltext.study @t Gmail

Development of optimized Cu–ZSM-5 deNOx catalytic materials both for HC-SCR applications and as FCC catalytic additives

Paper ID Volume ID Publish Year Pages File Format Full-Text
43669 45981 2007 8 PDF Available
Title
Development of optimized Cu–ZSM-5 deNOx catalytic materials both for HC-SCR applications and as FCC catalytic additives
Abstract

Cu-exchanged ZSM-5 zeolites finely coated with CeO2 nanoparticles were tested in this work as catalysts for the selective catalytic reduction (SCR) of NO with C3H6. The CeO2 coated Cu/ZSM-5 shows lower maximum NO conversion activity compared to the non-coated Cu/ZSM-5 catalyst at relatively high temperatures (ca. 450 °C) but the former catalyst is significantly more active at lower temperatures (ca. 350 °C), especially at lower space velocities, both under dry and wet feed conditions. Under simultaneous addition of both SO2 and water in the feed, the beneficial effect of the CeO2 coating at lower reaction temperatures was retained only at low space velocities. The same Cu/ZSM-5 based samples were evaluated as fluid catalytic cracking (FCC) catalytic additives for the in situ reduction of NOx formed during regeneration of the coked FCC catalyst. The amounts of NO and CO emitted during regeneration of the spent FCC catalyst at 700 °C in the presence of Cu/ZSM-5 based additives were compared with those obtained when a commercial CO promoter was used in the FCC catalyst inventory. All Cu/ZSM-5 additives exhibited significant NO reduction ability, which was further enhanced by increasing the Cu loading or the amount of additive in the FCC catalyst. The CeO2-coated sample reached the highest deNOx performance (up to 78% NO reduction); however, all additives presented insufficient activity for CO oxidation. Simultaneous NO reduction and CO oxidation was achieved only when the CeO2-Cu/ZSM-5 additive was promoted with Rh or when the non-promoted additives were combined with a commercial CO promoter. Preliminary studies suggested that the Rh-promoted CeO2-Cu/ZSM-5 additives can be very effective for both NO reduction by CO and CO oxidation at certain O2 concentrations, such as in the O2-deficient zones of the FCC regenerator. Further studies are in progress in order to elucidate the reaction mechanism and optimize the additive's formulation.

Keywords
Cu–ZSM-5; NO reduction; FCC regenerator; CO oxidation; Rh–Ce promotion
First Page Preview
Development of optimized Cu–ZSM-5 deNOx catalytic materials both for HC-SCR applications and as FCC catalytic additives
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 325, Issue 2, 15 June 2007, Pages 345–352
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us