Fully copper-exchanged high-silica LTA zeolites as unrivaled hydrothermally stable NH3-SCR catalysts
Abstract
Diesel engine technology is still the most effective solution to meet tighter CO2 regulations in the mobility and transport sector. In implementation of fuel-efficient diesel engines, the poor thermal durability of lean nitrogen oxides (NOx) aftertreatment systems remains as one major technical hurdle. Divalent copper ions when fully exchanged into high-silica LTA zeolites are demonstrated to exhibit excellent activity maintenance for NOx reduction with NH3 under vehicle simulated conditions even after hydrothermal aging at 900 °C, a critical temperature that the current commercial Cu-SSZ-13 catalyst cannot overcome owing to thermal deactivation. Detailed structural characterizations confirm the presence of Cu2+ ions only at the center of single 6-rings that act not only as a catalytically active center, but also as a dealumination suppressor. The overall results render the copper-exchanged LTA zeolite attractive as a viable substitute for Cu-SSZ-13.
Citation
Ryu , T , Ahn , N H , Seo , S , Cho , J , Kim , H , Jo , D , Park , G T , Kim , P S , Kim , C H , Bruce , E L , Wright , P A , Nam , I-S & Hong , S B 2017 , ' Fully copper-exchanged high-silica LTA zeolites as unrivaled hydrothermally stable NH 3 -SCR catalysts ' , Angewandte Chemie International Edition , vol. 56 , no. 12 , pp. 3256-3260 . https://doi.org/10.1002/anie.201610547
Publication
Angewandte Chemie International Edition
Status
Peer reviewed
ISSN
1521-3773Type
Journal article
Description
We acknowledge financial support from the National Creative Research Initiative Program (2012R1A3A2048833) through the National Research Foundation of Korea and from Hyundai Motor Group. We also thank J. Y. Koo (POSTECH) for assistance with ESR measurements, K.-S. Lee and Y. H. Jung (8C and 9B, PAL, respectively) for help in X-ray absorption and diffraction data, S. P. Thompson (I11,DLS) for help in obtaining powder X-ray diffraction data, and PAL and DLS for beam time. PAL is supported by MSIP and POSTECH. We acknowledge financial support from the National Creative Research Initiative Program (2012R1A3A2048833) through the National Research Foundation of Korea and from Hyundai Motor Group. We also thank J. Y. Koo (POSTECH) for assistance with ESR measurements, K.-S. Lee and Y. H. Jung (8C and 9B, PAL, respectively) for help in X-ray absorption and diffraction data, S. P. Thompson (I11,DLS) for help in obtaining powder X-ray diffraction data, and PAL and DLS for beam time. PAL is supported by MSIP and POSTECH.Collections
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