Solid-State Ion-Exchange of Copper into Zeolites Facilitated by Ammonia at Low Temperature
Journal article, 2015

The effect of the gas phase during solid-state ion-exchange of copper into zeolites was studied by exposing physical mixtures of copper oxides (CuI2O and CuIIO) and zeolites (MFI, *BEA and CHA) to various combinations of NO, NH3, O2 and H2O. It is shown that heating these mixtures to 250°C results in active catalysts for the selective catalytic reduction of NO with NH3 (NH3-SCR), indicating that the Cu has become mobile at that temperature. Such treatment allows for a fast (<5-10 h) preparation of copper exchanged zeolites. Scanning transmission electron microscopy analysis of Cu-CHA prepared using this method shows homogenous distribution of the Cu in the primary particles of the zeolite. In situ XRD reveals that the Cu ion-exchange is related to the formation of CuI2O. When the zeolite is mixed with CuIIO, addition of NO to the NH3-containing gas phase enhances the formation of CuI2O, and the Cu ion-exchange. The mobility of Cu at low temperatures is proposed to be related to the formation of [CuI(NH3)x]+ (x≥2) complexes.

nitric oxide

ammonia

copper

low-temperature

zeolites

solid-state ion-exchange

Author

Soran Shwan

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Competence Centre for Catalysis (KCK)

Magnus Skoglundh

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Competence Centre for Catalysis (KCK)

Lars Lundegaard

Haldor Topsoe

Tiruvalam Ramchandra

Haldor Topsoe

Ton Janssens

Haldor Topsoe

Anna Carlsson

FEI Company

Peter Vennestrøm

Haldor Topsoe

ACS Catalysis

21555435 (eISSN)

Vol. 5 1 16-19

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Areas of Advance

Nanoscience and Nanotechnology

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Chemical Process Engineering

Materials Chemistry

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DOI

10.1021/cs5015139

More information

Latest update

3/27/2018