Table Of ContentMol.Sieves (2004) 4:1–200
DOI 10.1007/b94235
Vibrational Spectroscopy
Hellmut G.Karge1· Ekkehard Geidel2
1 Fritz-Haber-Institut der Max-Planck-Gesellschaft,Faradayweg 4–6,14195 Berlin,Germany
E-mail:[email protected]
2 Institut für Physikalische Chemie,Universität Hamburg,Bundesstraße 45,20146 Hamburg,
Germany.E-mail:[email protected]
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2 Theoretical Background . . . . . . . . . . . . . . . . . . . . . . 12
2.1 Normal Mode Analysis . . . . . . . . . . . . . . . . . . . . . . . 13
2.2 Molecular Mechanics . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3 Molecular Dynamics Simulations . . . . . . . . . . . . . . . . . 21
2.4 Quantum Mechanical Calculations . . . . . . . . . . . . . . . . 24
2.5 Some Selected Examples ofModeling Zeolite Vibrational
Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3 Spectra Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.1 Qualitative Interpretation . . . . . . . . . . . . . . . . . . . . . 35
3.2 Quantitative Evaluation . . . . . . . . . . . . . . . . . . . . . . 35
4 Experimental Techniques . . . . . . . . . . . . . . . . . . . . . 40
4.1 Transmission IR Spectroscopy . . . . . . . . . . . . . . . . . . . 40
4.2 Diffuse Reflectance IR (Fourier Transform) Spectroscopy
(DRIFT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.3 Photoacoustic IR Spectroscopy (PAS) . . . . . . . . . . . . . . . 43
4.4 Fourier Transform Infrared Emission Spectroscopy (FT-IRES) 44
4.5 Raman Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . 45
4.6 Inelastic Neutron Scattering Spectroscopy (INS) . . . . . . . . 47
5 Information Available from IR,Raman and Inelastic Neutron
Scattering Spectroscopy . . . . . . . . . . . . . . . . . . . . . . 48
5.1 Introductory Remarks . . . . . . . . . . . . . . . . . . . . . . . 48
5.2 Framework Modes . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.2.1 Pioneering Work . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.2.2 More Recent Investigations ofVarious Molecular Sieves . . . . 52
5.2.2.1 Faujasite-Type Zeolites (FAU) . . . . . . . . . . . . . . . . . . . 52
5.2.2.2 Zeolite A (LTA) . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.2.2.3 Sodalite (SOD) . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.2.2.4 Clinoptilolite (Heulandite-Like Structure,HEU) . . . . . . . . . 54
5.2.2.5 Erionite (ERI),Offretite (OFF) . . . . . . . . . . . . . . . . . . . 55
5.2.2.6 Zeolite L (LTL) . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
© Springer-Verlag Berlin Heidelberg 2004
2 H.G.Karge · E.Geidel
5.2.2.7 Zeolite Beta (BEA) . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.2.2.8 Ferrierite (FER) . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.2.2.9 Chabazite (CHA) . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.2.2.10 ZSM-5 (MFI),ZSM-11 (MEL),MCM-22 (MWW),
ZSM-35 (FER),ZSM-57 (MFS) . . . . . . . . . . . . . . . . . . . 56
5.2.2.11 AlPO s,SAPOs,MeAPOs . . . . . . . . . . . . . . . . . . . . . . 56
4
5.2.2.12 Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.2.3 Effect ofCation-Loading on Framework Vibrations . . . . . . . 57
5.2.4 Effect ofAdsorption on Framework Vibrations . . . . . . . . . 58
5.2.5 Effect ofDealumination and n /n Ratio on Framework
Si Al
Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
5.2.6 Effect ofIsomorphous Substitution on Framework Vibrations 61
5.3 Cation Vibrations . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.3.1 Cation Vibrations in Pure Zeolites . . . . . . . . . . . . . . . . . 64
5.3.2 Cation Vibrations Affected by Adsorption . . . . . . . . . . . . 71
5.4 Hydroxy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
5.4.1 Hydroxy Groups ofZeolites Characterized by IR Fundamental
Stretching Bands . . . . . . . . . . . . . . . . . . . . . . . . . . 73
5.4.1.1 Faujasite-Type Zeolites (FAU) . . . . . . . . . . . . . . . . . . . 73
5.4.1.1.1 Non-Modified Faujasite-Type Zeolites . . . . . . . . . . . . . . 74
5.4.1.1.2 Dealuminated Faujasite-Type Zeolites . . . . . . . . . . . . . . 78
5.4.1.1.3 Cation-Exchanged Faujasite-Type Zeolites . . . . . . . . . . . . 82
5.4.1.2 Other Zeolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
5.4.1.2.1 Zeolite A (LTA) . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
5.4.1.2.2 Zeolite L (LTL) . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
5.4.1.2.3 Mordenite (MOR) . . . . . . . . . . . . . . . . . . . . . . . . . . 86
5.4.1.2.4 Heulandite (HEU) and Clinoptilolite . . . . . . . . . . . . . . . 87
5.4.1.2.5 Erionite (ERI) and Offretite (OFF) . . . . . . . . . . . . . . . . 88
5.4.1.2.6 Zeolite Beta (BEA) . . . . . . . . . . . . . . . . . . . . . . . . . 88
5.4.1.2.7 Ferrierite (FER) . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
5.4.1.2.8 Zeolites ZSM-5 (MFI) and ZSM-11 (MEL) . . . . . . . . . . . . 91
5.4.1.2.9 Miscellaneous:Zeolites MCM-22 (MWW),Chabazite (CHA),
Omega (MAZ),ZSM-20 (EMT/FAU) and ZSM-22 (TON) . . . . 93
5.4.1.2.10 Isomorphously Substituted Molecular Sieves . . . . . . . . . . 94
5.4.1.2.11 SAPOs,MeAPOs and VPI-5 . . . . . . . . . . . . . . . . . . . . 94
5.4.2 Hydroxy Groups ofZeolites Characterized by Deformation,
Overtone and Combination Bands . . . . . . . . . . . . . . . . 97
5.4.2.1 Characterization by Transmission IR Spectroscopy . . . . . . . 97
5.4.2.2 Characterization by Diffuse Reflectance IR Spectroscopy . . . . 98
5.4.2.3 Characterization by Inelastic Neutron Scattering
Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
5.5 Characterization ofZeolite/Adsorbate Systems . . . . . . . . . 103
5.5.1 Introductory Remarks . . . . . . . . . . . . . . . . . . . . . . . 103
5.5.2 Selected Zeolite/Adsorbate Systems . . . . . . . . . . . . . . . . 106
5.5.2.1 Homonuclear Diatomic Molecules (N ,H ,D ,O )
2 2 2 2
as Adsorbates . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
5.5.2.2 Carbon Monoxide (CO) as an Adsorbate . . . . . . . . . . . . . 111
Vibrational Spectroscopy 3
5.5.2.3 Linear Triatomic Molecules (N O,CO ) as Adsorbates . . . . . . 119
2 2
5.5.2.4 Methane (CH ) as an Adsorbate . . . . . . . . . . . . . . . . . . 122
4
5.5.2.5 Bent Triatomic Molecules (SO ,H S,H O) as Adsorbates . . . . 124
2 2 2
5.5.2.6 Adsorption ofProbe Molecules for the Characterization of
Zeolitic Acidity and Basicity . . . . . . . . . . . . . . . . . . . . 130
5.5.2.6.1 Introductory Remarks . . . . . . . . . . . . . . . . . . . . . . . 130
5.5.2.6.2 Pyridine,Ammonia and Amines as Probes for Acid Sites . . . . 131
5.5.2.6.3 Hydrogen (Deuterium),Light Paraffins and Nitrogen as Probes
for Acid Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
5.5.2.6.4 Nitriles as Probes for Acid Sites . . . . . . . . . . . . . . . . . . 138
5.5.2.6.5 Halogenated Hydrocarbons and Phosphines as Probes for
Acid Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
5.5.2.6.6 Carbon Monoxide as a Probe for Acid Sites . . . . . . . . . . . . 140
5.5.2.6.7 Nitric Oxide as a Probe for Acid Sites . . . . . . . . . . . . . . . 143
5.5.2.6.8 Benzene and Phenol as Probes for Acid Sites . . . . . . . . . . . 145
5.5.2.6.9 Acetone and Acetylacetone as Probes for Acid Sites . . . . . . . 147
5.5.2.6.10 Probes for Basic Sites . . . . . . . . . . . . . . . . . . . . . . . . 147
5.5.2.7 Adsorption ofMethanol,Benzene,Simple Benzene Derivatives,
Light Alkanes,Boranes and Silanes . . . . . . . . . . . . . . . . 149
5.5.2.8 Adsorption ofLarge and Complex Molecules . . . . . . . . . . 153
5.5.2.9 Infrared Micro-Spectroscopy ofMolecules in Single Crystals
or Powders ofZeolites . . . . . . . . . . . . . . . . . . . . . . . 155
5.6 In-situ IR and Raman Spectroscopic Investigation ofProcesses
in Zeolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
5.6.1 Introductory Remarks . . . . . . . . . . . . . . . . . . . . . . . 156
5.6.2 Zeolite Synthesis and Crystallization . . . . . . . . . . . . . . . 156
5.6.3 Chemical Reactions in Zeolites . . . . . . . . . . . . . . . . . . 158
5.6.4 Diffusion in Zeolites . . . . . . . . . . . . . . . . . . . . . . . . 163
5.6.5 Kinetics ofSolid-State Ion Exchange in Zeolites . . . . . . . . . 168
6 Concluding Remarks . . . . . . . . . . . . . . . . . . . . . . . . 169
7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Abbreviationsa
A zeolite structure (LTA,cf.[235])
A absorbance of,e.g.,OH groups in IR,A(OH),etc.
A parameter in Eq.(13)
A,A parameter in the Buckingham term ofEq.(16)
i,j
A,A parameter in the Lennard-Jones potential ofEq.(18)
i,j
a Unfortunately, many of the above-indicated abbreviations have various meanings (vide
supra);in view ofthe current conventions in the literature,this is hardlyavoidable.However,
thecorrect meaning ofthe abbreviations should follow from the respective context.
4 H.G.Karge · E.Geidel
A initial absorbance
initial
A integrated absorbance
int
AD adsorption energy
AN acetonitrile
AlPO –n microporous aluminophosphate zeolite-like structure
4
(n=5,8,11,20,...,cf.[235])
A maximal absorbance
max
A absorbance after treatment
treat
B Brønsted (e.g.,Brønsted acid sites,B-sites,Brønsted acidity)
B parameter in Eq.(13)
B,B parameter in the Lennard-Jones potential ofEq.(18)
i,j
B formation matrix between internal and Cartesian displacement
33
coordinates
B benzene
BATE boric acid trimethyl ester
BEA zeolite structure,acronym for zeolite Beta (cf.[235])
bpy 2,2¢-bipyridine
[B]ZSM-5 zeolite structure (MFI,cf.[235]) containing boron in the
framework
C cation (C) site,cation Lewis acid site
C,C parameter in the Buckingham term ofEq.(16)
i,j
C parameter in the dispersion term ofthe potential function
i,j
Eq.(21)
c concentration
c velocity oflight
0
C Brodskii constant in Eq.(24)
B
CA chemical analysis
CE conventional ion exchange
CHA zeolite structure;acronym for chabazite,(cf.[235])
CLIN abbreviation ofclinoptilolite;note:not a three-letter code
according to [235];(clinoptilolite is isostructural with
heulandite,HEU)
CoAPO–n microporous aluminophosphate zeolite-like structures with
cobalt in the AlPO –n framework (i.e.,MeAPO–n,Me=Co,
4
n=5 (AFT structure),n=11 (AEL structure),n=e.g.,31,37,
40,...cf.[235])
D transport diffusion coefficient
D(B) diffusion coefficient ofbenzene
D(T) diffusion coefficient oftoluene
d thickness (ofa zeolite wafer in,e.g.,mg cm–2)
DAM-1 Dallas amorphous material
DAY dealuminated Y-type zeolite
DEB diethylbenzene
DENOX process for removal ofnitrogen oxides
DEXAFS dispersive extended x-ray absorption fine structure
DFT density functional theory
DM dimethylphosphine
Vibrational Spectroscopy 5
D4R double four-membered ring in,e.g.,the structure ofzeolite A
D6R double six-membered ring in,e.g.,the structure ofzeolites X or Y
D6R indicates a four-membered ring in the hexagonal prism of
Fig.5
DPPH 2,2-diphenyl-1-picrylhydrazyl,ESR standard
DRIFT diffuse reflectance IR Fourier transform (spectroscopy)
DRS diffuse reflectance spectroscopy (in IR or UV-Visible region)
DTG differential thermogravimetry
DH (differential) heat ofadsorption
ad
E total energy
E unit matrix
33
EB ethylbenzene
EDAX energy dispersive x-ray (spectroscopy)
EDS energy dispersive x-ray spectroscopy
ElAPSO an MeAPSO material (see below) which contains in addition to
the elements ofMeAPSO other ones (Li,Be,B,Ga,Ge,As,or Ti)
[957]
EM energy minimization
EMT zeolite structure;hexagonal faujasite (cf.[235])
EMT/FAU structural intermediate (cf.ZSM-20,[235])
ERI zeolite structure;acronym for erionite (cf.[235])
ESR electron spin resonance (spectroscopy)
Et N triethylamine
3
ETS-4 zeolite structure related to zorite (cf.[313–316])
ETS-10 zeolite structure (cf.[313–316])
EXAFS extended x-ray absorption fine structure
F Schuster-Kubelka-Munk remission function
F force constant matrix
33
F force constant
F elements ofthe force constant matrix
i,j
Fr stretching force constant
Fa bending force constant
F second derivative ofthe total energy with respect to Cartesian
X
coordinates
frr,faa,fra interaction force constants related to atomic distances (rr),
i,j i,j i,j
bond angles (aa),simultaneous change ofatomic distances
and bond angles (ra)
F stretching force constants ofTO bonds (T=Si,Al;cf.Eq.(13))
TO
F stretching force constant ofthe SiO bond
SiO
F stretching force constant ofthe AlO bond
AlO
f(n) density ofvibrational states
F electric field strength
R
F second derivative ofthe total energy with respect to internal
R
coordinates
FAU zeolite structure;acronym for faujasite (cf.[235])
[Fe]ZSM-5 zeolite structure (MFI,cf.[235]) containing iron in the framework;
cf.footnoteb
6 H.G.Karge · E.Geidel
[Fe]MCM-41 mesoporous MCM-41 material containing iron in the pore walls,
cf.footnoteb
FER zeolite structure;acronym for ferrierite (cf.[235])
FIR far infrared (spectroscopy)
FR frequency response (spectroscopy)
FKS Flanigen-Khatami-Szymanski (correlation)
fs femtosecond (=10–15s)
FT Fourier transform
FTIR Fourier transform infrared (spectroscopy)
FT-IRES Fourier transform infrared emission spectroscopy
FWHH full-width at half-height (ofa band)
G–1 kinetic energy matrix
33
[Ga]BEA zeolite with Beta (BEA) structure containing gallium in the
framework,(cf.[530–534])
[Ga]ZSM-5 zeolite with MFI structure containing gallium in the framework,
(cf.[530])
GC gas chromatography
GF indicates Wilson’s method to solve vibrational problems using the
inverse ofthe kinetic energy matrix and the force constant matrix
GVFF generalized valence force field
ˆ
H Hamilton operator
h Planck’s constant
H Hammett value (acidity and basicity scale)
0
HEU zeolite structure;acronym for heulandite (cf.[235])
HF Hartree-Fock (theory)
HF high frequency (e.g.,HF band ofOH)
1H MAS NMRproton magic angle spinning nuclear magnetic resonance
(spectroscopy)
HMS hexagonal mesoporous silicate [783]
I transmitted radiation energy
I incident radiation energy
0
INS inelastic neutron scattering
IQNS incoherent quasielastic neutron scattering
IR infrared (spectroscopy)
IRES infrared emission spectroscopy
IVFF internal valence force field
K absorption parameter in the Schuster-Kubelka-Munk remission
function ofEq.(28)
KED kinetic energy distribution
K harmonic spring constant between a positively charged mass
i
point and a negatively charged massless shell in Eq.(17)
b Presenting an element symbol in square brackets should indicate that the respective element
is supposed to be incorporated into the framework ofthe material designated by the sub-
sequent acronym or abbreviation.For instance,“[Ti]SOD”is indicating that titanium is in-
corporated into the framework ofsodalite.
Vibrational Spectroscopy 7
k improved angle bending force constant in Eq.(20)
a
L matrix transforming internal into normal coordinates
33
L Lewis (e.g.,Lewis acid sites,L-sites,Lewis acidity)
L zeolite structure (LTL structure,cf.[235])
LF low-frequency (e.g.,LF band ofOH)
LO longitudinal optical (splitting)
LTA Linde type A zeolite (cf.[235])
LTL Linde type L zeolite (cf.[235])
M diagonal matrix ofatomic masses
44
M metal or metal cation
M indicates a metal ofsort 1,e.g.,Na
1
M indicates a metal ofsort 2,e.g.,Ca
2
m cation mass (cf.,e.g.,Eq.(24))
MAS NMR magic angle spinning nuclear magnetic resonance (spectroscopy)
MAZ zeolite structure;acronym for mazzite (cf.[235])
MFI zeolite structure (of,e.g.,ZSM-5 or silicalite,cf.[235])
MD molecular dynamics
MeAPO microporous metal aluminophosphate zeolite-like structure with
metal (Me) in the framework [235,501,957]
MAPSO-37 an MeAPSO material (see below) with Me=Mg [235,501,957]
MeAPSO microporous metal aluminophospate zeolite-like structures with
metal (Me) and additionally silicon in the framework [235,
501,957]
MCM-22 zeolite structure (acronym or IZA structure code is MWW;
cf.[235])
MCM-41 mesoporous material with hexagonal arrangement ofthe uniform
mesopores (cf.Volume 1,Chapter 4 ofthis series)
MCM-48 mesoporous material with cubic arrangement ofthe uniform
mesopores (cf.Volume 1,Chapter 4 ofthis series)
MCM-58 zeolite structure (acronym or IZA structure code is IFR)
MIR mid infrared (spectroscopy)
MM molecular mechanics
MO molecular orbital
MOR zeolite structure;acronym for mordenite (cf.[235])
MP2 Møller-Plesset perturbation theory truncated at second order
MR membered ring (xMR:x-membered ring,x=3,4,5,6,8,10,12,etc.)
n librational quantum number
n /n ratio ofmetal to aluminum atoms in the framework
M Al
n /n ratio ofsilicon to aluminum atoms in the framework
Si Al
n-Bu N tri-n-butylamine
3
NCA normal coordinate analysis
NCL-1 high-silica (n /n =20 to infinity) zeolite (cf.[337])
Si Al
NMA normal mode analysis
NIR near infrared (spectroscopy)
NIR-FT near infrared Fourier transform (spectroscopy)
NU-1 zeolite structure (cf.RUT,RUB-10 [235])
OFF zeolite structure,acronym for offretite (cf.[235])
8 H.G.Karge · E.Geidel
O-T-O angle between adjacent T (T=Si,Al,etc.) and O atoms inside a
tetrahedron
OTO framework fragment,i.e.,OSiO or OAlO
P branch ofa vibrational-rotational spectrum (P branch)
p,p parameter in the Buckingham term ofEq.(16)
i,j
PAS photoacoustic (infrared) spectroscopy
Pc phthalocyanine
PED potential energy distribution
PES potential energy surface
n-Pr N tri-n-propylamine
3
PT proton transfer
PV pivalonitrile (2,2-dimethylproprionitrile)
p-X para-xylene
Py pyridine
Q branch ofa vibrational-rotational spectrum (Q branch)
Q normal coordinate (column vector)
•
Q time derivative ofthe normal coordinate
QT transpose ofthe column vector Q
q,q,q atomic charges
i j
q cation charges
QM quantum mechanical (calculations)
R internal displacement coordinate (column vector)
•
R time derivative ofan internal displacement coordinate
R branch ofa vibrational-rotational spectrum (R branch)
R diffuse reflectance ofan infinitely (i.e.,very) thick sample
•
R actual distance between the ith core and its shell in Eq.(17)
i
RR resonance Raman (spectroscopy)
r cation radius
r,r atomic distances along chemical bonds
i j
r bond length between T and O (T=Si,Al) in Eq.(13)
TO
RE rare earth metal (cation)
RHO zeolite structure,acronym for zeolite rho (cf.[235])
S1,S2,S3 cation positions in the structure ofzeolite A (adjacent to the
single six-membered ring openings to the b-cages,near the center
ofthe eight-membered ring openings to the (large) a-cages and in
the center ofthe (large) a-cages,respectively)
SI,SI¢,SII,SII¢,SIII cation positions in zeolite X or Y,i.e.,FAU (cf.[236])
S scattering parameter in the Schuster-Kubelka-Munk remission
function ofEq.(28)
s,s ionic radii
i j
SAPO-n microporous silicoaluminophosphates,n=5,17,18,20,31,34,39
etc.(cf.[235])
SCR selective catalytic reduction
[Si]MFI MFI-type zeolite structure containing (exclusively) Si as T-atoms,
i.e.silicalite-1;cf.footnoteb
[Si]SOD SOD-type zeolite structure containing (exclusively) Si as T-atoms;
cf.footnoteb
Vibrational Spectroscopy 9
[Si,Fe]MFI MFI-type zeolite structure containing Si and Fe as T-atoms;
cf.footnoteb
[Si,Ti]MFI MFI-type zeolite structure containing Si and Ti as T-atoms;
cf.footnoteb
[Si,Fe]BEA zeolite structure ofBeta-type (BEA) with small amounts ofiron
besides silicon in the framework;cf.footnoteb
[Si,Ti]BEA zeolite structure ofBeta-type (BEA) with small amounts of
titanium besides silicon in the framework,[336];cf.footnoteb
[Si,V]MFI MFI-type zeolite structure with small amounts ofvanadium
besides silicon in the framework;cf.footnoteb
[Si,Ti]MFE zeolite structure ofZSM-11 type (MFE) with small amounts of
titanium besides silicon in the framework;cf.footnoteb
[Si,Al]MCM-41 mesoporous MCM-41 material containing both silicon and
aluminum in the walls ofthe pores,[350,351];cf.footnoteb
[Si,Ti]MCM-41 mesoporous MCM-41 material containing both silicon and
titanium in the walls ofthe pores [350,351];cf.footnoteb
[Si,V]MCM-41 mesoporous MCM-41 material containing both silicon and
vanadium in the walls ofthe pores [350,351];cf.footnoteb
SGVFF simplified generalized valence force field
S intermediate Sanderson electronegativity
int
SOD zeolite structure,acronym for sodalite (cf.[235])
SOD four-membered rings in the sodalite structure (particular
meaning in Fig.5)
SQM scaled quantum mechanical (force field)
SSZ-n series ofzeolite structures;aluminosilicates,e.g.,SSZ-24 and
SSZ-13,isostructural with corresponding aluminophosphates,
AlPO –5 (AFI) and AlPO –34 (CHA structure) (cf.[235])
4 4
SUZ-4 zeolite structure [877]
T (tetrahedrally coordinated) framework atom (cation) such as
Si,Al,Ti,Fe,V,B
T absolute temperature,in Kelvin (K)
T indicating the transpose ofa matrix or column vector
T kinetic energy
T transmittance (transmission)
T* transmittance (transmission) ofthe background (base line)
T toluene
TAPSO Ti-containing microporous silicoaluminophosphate ofthe
MeAPSO family [335,573]
T kinetic energy ofelectrons
E
T kinetic energy ofnuclei
N
TEHEAOH triethyl(2-hydroxyethyl)ammonium hydroxide
[Ti]MMM-1 Ti-containing material with both mesoporous (MCM-41) and
microporous (TS-1) constituents [353];cf.footnotebofthe table
TO framework fragment (SiO,AlO,etc.)
TMP trimethylphosphine
TO transversal optical (splitting)
TON zeolite structure;acronym for theta-1 (cf.[235])
10 H.G.Karge · E.Geidel
T-O-T angle between adjacent T and O atoms (T=Si,Al,Ti,etc.)
TPA tetrapropylammonium
TPAOH tetrapropylammonium hydroxide
TPD temperature-programmed desorption
TPO temperature-programmed oxidation
TPR temperature-programmed reduction
TS-1 ZSM-5 (MFI) structure containing small amounts oftitanium
besides silicon in the framework
TS-2 ZSM-11 (MFE) structure containing small amounts oftitanium
besides silicon in the framework
TMS tetramethylsilane
UV-Vis ultraviolet-visible (spectroscopy)
US-Y ultrastable Y-type zeolite
V potential energy
V term ofthe potential function accounting for the electrostatic
framework-cation interaction
Vcore-shell additional term ofthe potential function accounting for oxygen
anions and extra-framework cations
V potential energy originating from electron-electron repulsion
EE
V potential energy originating from nucleus-nucleus repulsion
NN
V potential energy originating from electron-nucleus attraction
EN
V Lennard-Jones (12–6) potential
ij
v vibrational quantum number
VPI-5 microporous aluminophosphate zeolite-like structure (VFI,
cf.[235])
VPI-7 zeolite structure (VSV;cf.[235,279,280])
VPI-8 microporous all-silica zeolite-like structure (VET,cf.[235])
VS-1 zeolite structure (MFI,cf.[235]) containing vanadium besides
silicon in the framework
[V]ZSM-5 zeolite structure (MFI,cf.[235]) containing vanadium in the
framework (VS-1);cf.footnoteb
[V]MCM-41 mesoporous MCM-41 material containing vanadium in the
pore walls
X zeolite structure (faujasite-type structure with n /n <2.5,
Si Al
cf.[235])
X xylene
XAS x-ray absorption spectroscopy
XRD x-ray diffraction
Y zeolite structure (faujasite-type structure with n /n ≥2.5,
Si Al
cf.[235])
YAG yttrium aluminum garnet (laser)
Z frequently used as an abbreviation of“zeolite”or a (charged)
“zeolite fragment”
ZBS zirconium-containing mesoporous material [778]
ZK-4 zeolite structure (LTA,cf.[235])
ZSM-5 zeolite structure (MFI,cf.[235])
ZSM-11 zeolite structure (MFE,cf.[235])
