Influence of organic templates on the structure and on the concentration of framework metal ions in microporous aluminophosphate catalysts.
1112 - 1118.
Energy minimization methods are used to investigate the packing energies of triethylamine and triethylammonium templates in two distinct aluminosilicate structures, AIPO(4)-5 (AFI code) and the chabazitic AIPO(4)-34 polymorph (CHA), both of which may be synthesized as Co-AIPOs from the same gel, depending on the concentration of Co2+ and template. We show that higher (cationic) concentrations of template, induced by higher (negatively charged) Co2+ substitution levels in the framework, favor the formation of a chabazitic structure. The AIPO(4)-5 polymorph is, however, marginally more stable in the untemplated state, a result which is consistent with the reversion of the chabazitic phase to the AIPO(4)-5 polymorph at higher temperatures or increased reaction time.
|Title:||Influence of organic templates on the structure and on the concentration of framework metal ions in microporous aluminophosphate catalysts|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Chemistry|
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