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Abstract:
Samples of two differently prepared zeolite rho loaded with different amounts of dimethylamine (DMA) were studied in their hydrated forms by X-ray diffraction. Both zeolites are partially dealuminated, as indicated by nonframework A1 which is assumed to be Al2O3 or AlOOH. Series I was prepared from dry-calcined NHn-rho at 873 K, series II from steam-calcined NHn-rho at 773 K. The samples were loaded with different amounts of DMA. Rietveld refinements yielded the following results for series I: (1) H3.8(H-DMA)5Cs0.2Al9Si39O96.Al2O3.21H2O, X-ray data collection at room temperature, Im3̅m, a = 15.0590 (2) Å, Rwp = 0.089; (2) (H-DMA)8.8Cs0.2Al9Si39O96.Al2O3.18H2O, X-ray data collection at room temperature, Im3̅m, a = 15.0680 (2) Å, Rwp = 0.091. Series II: (3) H0.3(H-DMA)5Cs0.7Al6Si42O96.2.5Al2O3.24H2O, X-ray data collection at room temperature, Im3̅m, a = 15.0596 (2) Å, Rwp = 0.120. DMA resides on the center axis through the α-cage with the N atoms pointing to the single eight-ring and the two methyl groups oriented towards the center of the α-cage.
