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Fully Copper‐Exchanged High‐Silica LTA Zeolites as Unrivaled Hydrothermally Stable NH 3 ‐SCR Catalysts
Author(s) -
Ryu Taekyung,
Ahn Nak Ho,
Seo Seungwan,
Cho Jung,
Kim Hyojun,
Jo Donghui,
Park Gi Tae,
Kim Pyung Soon,
Kim Chang Hwan,
Bruce Elliott L.,
Wright Paul A.,
Nam InSik,
Hong Suk Bong
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201610547
Subject(s) - nox , zeolite , diesel fuel , catalysis , copper , chemistry , hydrothermal circulation , chemical engineering , selective catalytic reduction , inorganic chemistry , combustion , organic chemistry , engineering
Diesel engine technology is still the most effective solution to meet tighter CO 2 regulations in the mobility and transport sector. In implementation of fuel‐efficient diesel engines, the poor thermal durability of lean nitrogen oxides (NO x ) 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 NO x reduction with NH 3 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 Cu 2+ 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.