TY - JOUR
T1 - Inelastic neutron scattering of Na-zeolite A with in situ ammoniation
T2 - An examination of initial coordination
AU - Seel, A.G.
AU - Sartbaeva, A.
AU - Edwards, P.P.
AU - Rammirez-Cuesta, A.J.
PY - 2010/9/7
Y1 - 2010/9/7
N2 - The detection and rationalization of the coordination of low concentrations of ammonia within Na-zeolite A is carried out by the application of inelastic neutron scattering (INS), using inverse geometry time of flight spectrometry to study the partial phonon density of states of in situ ammoniated Na-zeolite A. The experimental spectra are subsequently characterised by density functional calculations, incorporating pre-optimisation by geometric simulation. We find that at a concentration of four ammonia molecules per α-cage, the ammonia molecule coordinates with extra-framework Na* cations and gives rise to three structured regions in the INS spectrum. We show that these regions correspond to translational, librational and tilting motions of the ammonia molecule. These results are in agreement structurally with previous studies of ammonia within a zeolite, and thus show that INS is a valid technique for such investigations.
AB - The detection and rationalization of the coordination of low concentrations of ammonia within Na-zeolite A is carried out by the application of inelastic neutron scattering (INS), using inverse geometry time of flight spectrometry to study the partial phonon density of states of in situ ammoniated Na-zeolite A. The experimental spectra are subsequently characterised by density functional calculations, incorporating pre-optimisation by geometric simulation. We find that at a concentration of four ammonia molecules per α-cage, the ammonia molecule coordinates with extra-framework Na* cations and gives rise to three structured regions in the INS spectrum. We show that these regions correspond to translational, librational and tilting motions of the ammonia molecule. These results are in agreement structurally with previous studies of ammonia within a zeolite, and thus show that INS is a valid technique for such investigations.
UR - http://www.scopus.com/inward/record.url?scp=77955876456&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1039/C003567J
U2 - 10.1039/c003567j
DO - 10.1039/c003567j
M3 - Article
AN - SCOPUS:77955876456
SN - 1463-9076
VL - 12
SP - 9661
EP - 9666
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 33
ER -