Abstract
The use of transition metal cations complexed by polyamines as structure directing agents (SDAs) for silicoaluminophosphate (SAPO) zeotypes provides a route, via removal of the organic by calcination, to microporous solids with well-distributed, catalytically-active extra-framework cations and avoids the need for post-synthesis aqueous cation exchange. Iron(II) complexed with tetraethylenepentamine (TEPA) is found to be an effective SDA for SAPO- 34, giving as-prepared solids where Fe2+-TEPA complexes reside within the cha cages, as indicated by Mössbauer, optical and X-ray absorption near edge spectroscopies. By contrast, when non-coordinating tetraethylammonium ions are used as the SDAs in Fe-SAPO-34 preparations, iron is included as octahedral Fe3+ within the framework. The complex- containing Fe-SAPO-34(TEPA) materials give a characteristic visible absorption band at 550 nm (and purple colouration) when dried in air that is attributed to oxygen chemisorption. Some other Fe2+ polyamine complexes (diethylenetriamine, triethylenetetramine and pentaethylenehexamine) show similar behaviour. After calcination in flowing oxygen at 550 °C, ‘one-pot’ Fe(TEPA) materials possess Fe3+ cations and a characteristic UV-visible spectrum: they also show appreciable activity in the selective catalytic reduction of NO with NH3.
Original language | English |
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Pages (from-to) | 4366-4374 |
Journal | Catalysis Science & Technology |
Volume | 7 |
Issue number | 19 |
Early online date | 29 Aug 2017 |
DOIs | |
Publication status | E-pub ahead of print - 29 Aug 2017 |
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Synthesis and activation for catalysis of Fe-SAPO-34 prepared using iron polyamine complexes as structure directing agents (dataset)
Turrina, A. (Creator), Dugulan, A. I. (Creator), Collier, J. E. (Creator), Walton, R. I. (Creator), Casci, J. L. (Creator) & Wright, P. A. (Creator), University of St Andrews, 30 Aug 2017
DOI: 10.17630/599b513d-b173-425c-ac2c-0ccfc50d8798
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