BACKGROUND
Soot, produced fiom the incomplete combustion of the coal, oil (such as diesel
oil), wood or other carbonaceous materials, mainly consists of carbon. The exhaust
gas of a diesel engine has a high level of carbonaceous soot, which is undesirable in
view of environment protection. One approach for reducingleliminating the soot
emissions of a diesel engine is the employment of a diesel particulate filter in the
exhaust gas system of the diesel engine. In order to decrease the temperature for
periodically regenerating the diesel particulate filter and perform the regeneration
continuously in situ, catalysts may be added to the diesel fuel, or may be impregnated
in or coateddeposited onto the wall(s) of the diesel particulate filter to promote the
oxidization of soot trapped in the diesel particulate filter at a relatively low
oxidization initiation temperature.
US patent No. 7,797,93 1 discloses a catalyst composition for use on a diesel
particulate filter for facilitating soot oxidation comprising a catalytic metal
comprising a platinum group metal selected fiom the group consisting of Pt, Pd, Pt-
Pd, and combinations thereof and the cost of platinum group metals are high.
US patent application publication No. 2009102035 17 discloses a carbon-based
combustion catalyst obtained by burning sodalite or the mixture of sodalite with an
alkali metal source andor an alkaline earth metal source.
Interstitial Cristobalite-type Compounds (Na20)l~.33Na[A1Si04]
((Na20)~o.66Na2[A12Si208]o, r Na<3.32A12Si2018.66h) ave been reported in an article
titled as Interstitial Cristobalite-type Compounds (Na20)lo.33Na[A1Si04] and
published in JOURNAL OF SOLID STATE CHEMISTRY 61, 40-46 (1986).
Na8A14Si401(8o r (Na20)Na2[Al2Si2O8]o,r Na4A12Si209h) as been reported in Beitrage
zur Beaktionsfahigkeit der silicate bei niedrigen temperaturen, 11. Mitteilung., Die
Strukturen Na20-reicher carnegieite., Von Werner Borchert und Jurgen Keidel,
Heidelberg, Mit 6 Textabbildungen, (Eingegangen am 17, Marz 1947). US patent
application publication No. 201 1/03 19690 discloses that a carnegieite-like material of
formula (Na20),Na2[A12Si20s], wherein OO; 11a13; lSb13; and 0<6132/3.
In another aspect, the invention relates to an exhaust gas system comprising
the material of formula I.
In yet another aspect, the invention relates to a method including: contacting a
carbonaceous material with an effective amount of the material of formula I to initiate
the oxidization of the carbonaceous material at a first oxidization initiation
temperature, wherein the first oxidization initiation temperature is lower than an
oxidization initiation temperature of the carbonaceous haterial when a catalyst is not
present.
DRAWINGS
These and other features, aspects, and advantages of the present invention will
become better understood when the following detailed description is read with
reference to the accompanying drawings, wherein:
FIG. 1A illustrates a visualized crystal structure of NqA14Si4016
(2~a2A12Si208h]a)v ing a carnegieite phase;
FIG. 1 B shows a visualized crystal structure of 2[Na22,3A12Si2032/3] including
face centered cubic (FCC) lattices forming F -4 3 m cubic structure;
FIG. 2 shows X-ray diffraction (XRD) patterns in 2-theta-scale of
corresponding samples in example 1 ;
FIG. 3 shows X-ray diffraction (XRD) patterns in 2-theta-scale of
corresponding sample before and after treatment in example 2;
FIG. 4 shows the mass spectrometer (MS) signals of carbon dioxide generated
from different samples at different temperatures in example 3;
FIG. 5 shows the mass spectrometer (MS) signals of carbon dioxide generated
from different samples at different temperatures in example 4;
FIG. 6 shows the mass spectrometer (MS) signals of carbon dioxide generated
from different samples at different temperatures in example 5;
FIG. 7 is a graph showing the normalized COX generated from different
samples at different temperatures in example 7; and
FIG. 8 shows the COX yield of different samples at different temperatures in
example 9.
DETAILED DESCRIPTION
Any numerical values recited herein include all values fiom the lower value to
the upper value in increments of one unit provided that there is a separation of at least
2 units between any lower value and any higher value. As an example, if it is stated
that the amount of a component or a value of a process variable such as, for example,
temperature, pressure, time and the like is, for example, fiom 1 to 90, preferably from
20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85,22
to 68, 43 to 51, 30 to 32 etc. are expressly enumerated in this specification. For
4
values which are less than one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1
as appropriate. These are only examples of what is specifically intended and all
possible combinations of numerical values between the lowest value and the highest
value enumerated are to be considered to be expressly stated in this application in a
similar manner.
Approximating language, as used herein throughout the specification and
claims, may be applied to modify any quantitative representation that could
permissibly vary without resulting in a change in the basic function to which it is
related. Accordingly, a value modified by a term or terms, such as "about", is not to
be limited to the precise value specified. In some instances, the approximating
language may correspond to the precision of an instrument for measuring the value.
As used herein, the terms "may", "could", "could be" and "may be" indicate a
possibility of an occurrence within a set of circumstances; a possession of a specified
property, characteristic or function; and/or qualify another verb by expressing one or
more of an ability, capability, or possibility associated with the qualified verb.
Accordingly, usage of "may" and "may be" indicates that a modified term is
apparently appropriate, capable, or suitable for an indicated capacity, function, or
usage, while taking into account that in some circumstances, the modified term may
sometimes not be appropriate, capable, or suitable. For example, in some
circumstances, an event or capacity may be expected, while in other circumstances,
the event or capacity may not occur. This distinction is captured by the terms "may",
"could", "could be" and "may be".
The material of formula I is a crystal having a carnegieite phase, i.e., including
face centered cubic (FCC) lattices forming F -4 3 m cubic structure. In some
embodiments, y=O, the material may be of a crystal structure of Na&l4Si4Ol6 with a
carnegieite phase enriched by sodium oxide. In some embodiments, y>O, the material
may be of a crystal structure of NqA14Si401~w ith a carnegieite phase enriched by
sodium oxide and with some components thereof being substituted by M.
For illustrative purpose, FIG. 1A shows a visualized crystal structure of
Na4Al4Si4ol6 (2[Na2A12Si208]) with a carnegieite phase, which is diamond cubic
structure composed of 2 face centered cubic (FCC) lattices (if considering Si ions take
the corner and face center position), with one lattice offsets from another along a body
diagonal by % of its length.
FIG. 1B shows a visualized crystal structure of 2[Na2213A12Si203213h]a ving
face centered cubic (FCC) lattices forming F -4 3 m cubic structure, assuming
4(Na20)+4/3(Na20) are incorporated into available octahedral and tetrahedral
interstitial spaces of the FCC lattices of Na&l4Si4Ol6.
e In some embodiments, M may be at least one of potassium, lithium, cerium,
cobalt, iron and vanadium.
According to examples of the invention, x and y vary depending on the
specific M in the material. In some embodiments, M is potassium and 3.21x13.8 and
0.21yS0.8. In some embodiments, M is lithium and x=3.8 and ~ 0 . 2 I.n some
embodiments, M is cobalt and x=3.8 and ~ 0 . 2In. some embodiments, M is cerium
and 3.81x13.9996 and 0.0004Sy10.2.
The values of a, b and 6 vary depending on the vacancies in the lattices. In
some embodiments, the material is of formula: Na3,8&.2A12Si209, Na3.6K0.4A12Si209,
Na3.2Ko.8A12Siz09, Na3.8Lio.2A12Si209, Na3.8Ceo.2A12Si209.3, Na~A12Si209.5, a Na3.998Ce0.002A12Si209.003~ Na3.9996Ce0.0004A12Si209.0002~ Na3.72&.24A12Sil.9208.82 Or
Na3.8Co0.2A12Si209.2.
According to examples of the invention, the values of x, y, a, b and 6 may be
calculated using the amounts of materials used for preparing the material of formula I.
In some embodiments, the amounts of Na, M, Al, and Si in the material of formula I
may be detected using such as a wave dispersive x-ray fluorescence (WD XRF)
analyzer to obtain the values of x, y, a and b followed by calculating the value of 6
according to the balance of charges of all elements in the material.
In some embodiments, the material of formula I is used in a diesel particulate
filter of an exhaust gas system for receiving the diesel exhaust gas from a diesel
engine. In some embodiments, the material is coated on the diesel particulate filter by
soaking the diesel particulate filter in a slurry comprising the material and drying the
diesel particulate filter after being taken out of the slurry.
In some embodiments, the material of formula I is used by contacting a
carbonaceous material with an effective amount of the material to initiate the
oxidization of the carbonaceous material at a first oxidization initiation temperature;
wherein the first oxidization initiation temperature is lower than an oxidization
initiation temperature of the carbonaceous material when a catalyst is not present.
As used herein the term "the oxidization initiation temperature" refers to a
temperature at which the carbonaceous material starts to oxidize, or the lowest
temperature at which the carbonaceous material is able to be oxidized. In some
embodiments, the oxidization initiation temperature of the carbonaceous material may
be the temperature at which the carbonaceous material starts to generate carbon
monoxide and/or carbon dioxide or the temperature at which carbon monoxide and/or
carbon dioxide generated from the carbonaceous material is detectable.
The contacting of the carbonaceous material and the material of formula I may
be in any ways that the two materials may be contacted. In some embodiments, the
carbonaceous material and the material of formula I are mixed with each other. In
some embodiments, the material of formula I is impregnated in or coated/deposited
onto the walls of a diesel particulate filter which are exposed to the exhaust gas
stream comprising the carbonaceous material so the two materials may be contacted
with each other.
The materials may be contacted in an environment comprising an oxidant,
such as steam, nitrogen oxide(s), and air comprising oxygen.
As used herein the term "carbonaceous material" refers to but is not limited to
carbonaceous solid or liquid or particulates or macromolecules forming the
carbonaceous solid or liquid, which are derived from coal, petroleum, wood,
7
hydrocarbons and other materials containing carbon. According to examples of the
invention, the carbonaceous material may be at least one of hydrocarbon (e.g. diesel
oil), carbon black and soot.
The material of formula I may lower the oxidization initiation temperature of
the carbonaceous material, it may be a catalyst for the oxidization of the carbonaceous
material and a catalyst where soot needs to be removed through oxidization.
According to examples of the invention, the material of formula I is stable in
such environments as those comprising steam of high temperature.
EXAMPLES
The following examples are included to provide additional guidance to those
of ordinary skill in the art in practicing the claimed invention. These examples do not
limit the invention of the appended claims.
I Kaolin was obtained from Sigma-Aldrich Corp., St Louis, Missouri (MO),
USA. NaN03, KN03, LiN03, Ce(N03)3.6H20, Co(N03)2.6H20, citric acid,
triethylene glycol, and isopropanol were obtained from Sinopharm Chemical Reagent
Co., Ltd., Shanghai, China. Carbon black (99.99% carbon content, ACE Black, AB 50)
was obtained from synthetic oil and lubricant of Texas, Inc., Houston, TX, USA.
Unless otherwise specified, all the chemicals were used without further purification.
Unless specified otherwise, the values of 6 of the materials of formula
NaxM,A1,SibOs were calculated assuming sodium, potassium, lithium, cobalt, cerium,
cerium, aluminum and silicon exist in the materials in the forms of ~ a +K,', ~i',c o3+,
ce4+, AP+ and si4+.
Example 1
NaN03, KN03 (LiN03, Ce(N03)3.6H20o r CO(NO~)~.~Han~dO c)it ric acid
were completely dissolved in water to get a solution. Tri-ethylene glycol was then
added into the solution with stirring. Kaolin was finally added into the mixture and
stirred for 1 hour at room temperature to form a slurry. The slurry was gradually
8
heated up to 400°C. The heating was terminated when a powder was formed. The
powder was then placed in a muffle h a c e for calcination at 991 "C to form different
material of formula NaxMyA1,sibOs.
The amounts of NaN03, KN03, LiN03, Ce(N03)3-6H20, Co(N03)2.6H20,
kaolin and citric acid used for different material of formula NaXMyA1,SibOsa re listed
in table 1 below. The concentrations of K, Li, Ce, or Co and the values of x, y, a and b
are respectively calculated according to the amounts of NaN03, KN03 (LiN03,
Ce(N03)3.6H20o r CO(NO~)~.~Ha~nOd )k,a olin used for each material of formula
NaXM,AlaSibOs. The concentrations of K, Li, Ce, or Co, the values of x, y, and the
formula of each material are listed in table 1 below. e
Samples were respectively taken from materials of formula Na4A12Si209,
Na5A12Si209.5, Na3.8Ce0.2A12Si209.3, Na3.8&.2A12Si209, Na3.8Li0.2A12Si209,
Na3.8C00.2A12Si20t9o. 2b e measured by an X-ray diffractometer (XRD) (Bruker D8
Advance, Bruker Axs GmbH Karlsruhe, Germany) for phase identification. The X-ray
diffraction (XRD) patterns in 2-theta-scale of corresponding samples are shown in
FIG. 2.
It can be seen from FIG. 2 that diffraction peaks of X-ray diffraction (XRD)
patterns of all samples are at around 21, 34, 43, 49 and 62, indicating that the
carnegieite phases with Face Centered Cubic (fcc) lattices forming F -4 3 m cubic
structures were formed in all the samples.
Unless specified otherwise, the material of formula NaXMyAlaSibOuss ed in the
following samples were prepared in method described in example 1.
0
I
I
Table 1
-
-
5
0
NasA
12Si2
09.5
2 1.27
13.01
21.01
15.00
-
-
4
0
Na4
A12Si
209
7'0
-
-
-
-
13'0
21.0
15'0
Co
5%
3.8
0.20
0.2A12Si
209.2
16.14
-
-
2.91
13.01
21.02
14.82
M
concentra
tion of M
(moo
x
y
Formula
(8)
NaN03
KN03
(g)
LiN03
(€9
Ce(N03)
3.6H20
(g)
Co(N03)
*.6H20
(g)
kaolin
(g)
citric
acid (g)
triethylen
e glycol
(g)
5%
3.8
0.2000
0.2A12Si
209.3
16.16
-
-
4.34
13.01
21.03
15.02
500 ppm
3.998
0.0020
Na3.2KNa3.8LiNa3.8CoNa3.998CeNa3.w96CeNa3.8ce
0.002A12Si
209.003
16.99
-
-
0.0430
-
13.01
21.04
15.00
Ce
100 ppm
3.9996
0.0004
0.0004A12Si
209.0002
17.01
-
-
0.00879
-
13.00
21.03
15.69
Li
5%
3.8
0.20
0.2A12S
i209
16.16
-
0.69
13.00
21.03
14.99
20%
3.2
0.80
0.8A12S
i209
13.61
4.05
-
-
-
13.00
21.04
15.03
5%
3.8
0.20
Na3.8K
0.2A12S
i209
16.14
1.01
-
-
-
13.01
21.02
15.00
K
10%
3.6
0.40
Na3.6K
0.4A12S
i209
15.31
2.02
-
-
-
13.01
21.01
15.00
Example 2
Water (65 ml) was atomized by an atomizer to produce water mist which was
then carried into a heating furnace by a stream of N2 of 1.2 Llmin. The water mist
became steam in the heating furnace at temperature of 500°C. The water steam was
23% in the steam and N2 gas flow.
A sample of the material of formula Na3.8&.2A12Si209 (0.8832 g, from a
second batch different from the first batch from which the sample in example 1 was
obtained) was put in the heating furnace with the steam and N2 gas flow for treatment.
After 4 hours of treatment, the feeding of water mist was stopped and the heating
hrnace was turned off. The sample was taken out after the heating furnace was
cooled down.
The X-ray diffraction (XRD) patterns in 2-theta-scale of the sample of
material of formula Na3.8&.2A12Si209 before and after treatment are shown in FIG. 3.
It can be seen from FIG. 3 that after the treatment difiaction peaks of X-ray
diffraction (XRD) patterns barely changed, indicating that the carnegieite phases with
Face Centered Cubic (fcc) lattices forming F -4 3 m cubic structures were maintained.
Table 2 below shows the amounts of elements of the sample of material of
formula Na3.8K0.2A12Si20b9e fore and after the treatment according to a wave
dispersive x-ray fluorescence (WD XRF) analyzer (Rigaku ZSX 100e, Rigaku
Industrial Corporation, Osaka, Japan).
The data in table 2 indicate that potassium exists inside the crystal structure of
the material of formula Na3.8&.2A12Si209a nd not in the form of a water soluble salt.
The formula of the material of formula Na3.8&.2A12Si209 could also be written as
Na3.72Ko.24A12Sil.920u8s.i8n2g the WD XRF analysis data of the before treatment in
table 2.
--
Table 2
Example 3
Samples of materials of formula Na3.8&.2A12Si209( respectively from first and
second batches), Na3.8~.2A12Si2a0f9te r treatment in example 2, Na3.8Li0.2A12Si209,
Na4A12Si209,N a5A12Si209.5N, a3.8C00.2A12Si209.2N, a3.8Ce0.2A12Si209.3( 20.00 mg
each) and 2.00 mg carbon black were respectively mixed by mortar for 5-10 minutes
and were respectively loaded in to a thermo gravimetric analysis system (TGAJSDTA
851e, from Mettler Toledo, Inc.). A sample of carbon black (2.00 mg) was loaded to
the therrno gravimetric analysis system. The samples were heated up to 850°C at
S°C/min in air at 80 mumin, and then cooled down.
After the treatment
0.93
0.48
0.50
0.06
element
Na (mol)
Si (mol)
A1 (mol)
K (mol)
Quadstar-422 mass spectrometer (MS) from Pfeiffer Vacuum Corp. was used
to analyze the concentration of carbon dioxide generated from different samples at
different temperatures. The MS signals of carbon dioxide of different samples at
different temperatures are shown in FIG. 4.
Before the treatment
0.92
0.47
0.50
0.06
It can be seen from FIG. 4 that the starting temperature of the mixture of
Na3.8K0.2A12Si209(f irst and second batches), Na3.8&.2A12Si209a fter treatment in
example 2, Na3.8Li0.2A12Si209, Na3.8C00.2A12Si209.~N, a3.8Ce0.2A12Si~09.a3n d carbon
black to generate C02 (i.e., the temperature at which the MS signals in FIG. 4 started
to change) was lower than that for the mixture of Na4A12Si209 and carbon black, and
carbon black alone to generate CO2, indicating that the oxidization initiation
temperature of carbon black is lower when mixed with the material of formula
Na3.8K0.2A12Si20(f9ir st and second batches), Na3.8&.2A12Si209a fter treatment in
example 2, Na3.8Li0.2A12Si20N9a, 3.8C00.2A12Si209N.2a,3 .8Ce0.2A12Si209t.h3a n with the
material of formula N&Al2Si2O9 and alone.
In terms of the catalytic performances of the samples, the sequence was:
Na3.8K0.2A12Si20(f9i rst batch) > Na3.8&.2A12Si209a fter treatment in example 2>
Na3.8K0.2A12Si209(s econd batch) > Na3.8Li0.2A12Si209> Na3.8Ceo.2A12Si209.3 >
Na3.8C00.2A12Si209>.2 N aA12Si209> Na5A12Si209..5
Example 4
e Samples of carnegieite materials of formula Na3.8&.2A12Si209,
Na3.6K0.4A12Si20a9n,d NaA12Si209( 20.00 mg each) and 2.00 mg carbon black were
respectively mixed by mortar for 5-10 minutes and were respectively loaded into a
thennogravimetric analysis system (TGNSDTA 851e, from Mettler Toledo, Inc.). A
sample of carbon black (2.00 mg) was loaded to the thermogravimetric analysis
system. The samples were heated up to 850 "C at 5"CImin in air at 80 mllmin, and
then cooled down.
Quadstar-422 mass spectrometer (MS) from Pfeiffer Vacuum Corp. was used
to analyze the concentration of carbon dioxide generated from different samples at
different temperatures. The MS signals of carbon dioxide of different samples at
different temperatures are shown in FIG. 5. e
It can be seen from FIG. 5 that the starting temperature of the mixture of
Na3.8K0.2A12Si20a9n d carbon black to generate C02 was lower than that for other
mixtures and carbon black alone to generate C02, and that the oxidization initiation
temperature of carbon black is lower when mixed with the material of formula
Na3.8K0.2A12Si20th9a n with other carnegieite materials and alone.
Example 5
Samples of carnegieite materials of formula Na3,8Ce~.2A12Si209.3,
each) and 2.00 mg carbon black were respectively mixed by mortar for 5-10 minutes
13
and were respectively loaded in to a thermogravimetric analysis system (TGAISDTA
851e, from Mettler Toledo, Inc.). A sample of carbon black (2.00 mg) was loaded to
the thermogravimetric analysis system. The samples were heated up to 850 "C at
S°Clmin in air at 80 mllmin, and then cooled down.
Quadstar-422 mass spectrometer (MS) from Pfeiffer Vacuum Corp. was used
to analyze the concentration of carbon dioxide generated from different samples at
different temperatures. The MS signals of carbon dioxide of different samples at
different temperatures are shown in FIG. 6.
It can be seen from FIG. 6 that the sequence of catalytic performance was:
Na3.8Ce0.2A12Si209.3 > Na3.~~sCeo.oo2A12Si209.003 > NaA12Si209>
Na3.9996Ce0.0004A12Si209.0002.
Example 6
Powders of the material of formula Na3.8&.2A12Si209a nd 0.5 wt% Pt/Al2O3
(3 g each, 425 pm - 7 10 pm) were respectively packed in a quartz tube of 1 inch outer
diameter (OD) and 0.75 inch internal diameter (ID) to form a catalyst powder bed.
One end of each quartz tube was connected to a suction cup while the other end was
connected to a house vacuum.
I Soot from a diesel storm lamp was collected by a collection vessel and filtered
by the catalyst powder bed with the house vacuum on to form a soot cake. The top
layer of the soot cake on the front end of the catalyst powder bed was removed since
it was not in a close contact with the catalyst. The remaining catalyst powder with -
~ 1.5 wt% of soot was subsequently used in example 7.
Example 7
Catalyst powder (2.5 g, 425 - 710 pm) of Na3.8&.2A12Si209 and 0.5 wt%
Pt/A1203 respectively loaded with - 1.5 wt?h of soot (from Example 6) were
respectively packed in a quartz tube of 1 inch outer diameter (OD) and 0.75 inch inner
diameter (ID). The two tubes and a tube with only 2.5 g soot were placed in a tube
furnace.
14
A gas stream comprising 300 ppm of NO, 9% of 0 2 , 7% of H20 and balanced
with N2 was allowed to pass through the tube furnace. The total gas flow rate was 3.2
standard liters per minute (SLPM). The temperature of the tube furnace was ramped
from 40 "C to 640 "C at a rate of 20 OC115 min. Water was injected into the tube
furnace only when the tube furnace's temperature exceeded 120 "C to avoid
condensation.
The COX (CO and C02) concentration in the gas stream in the tube furnace
was measured by both the MultiGasTM 2030-HS High Speed Fourier Transform
Infrared (FTIR) Gas Analyzer fiom MKS Instruments and the Horiba Nondispersive
Infrared (NDIR) CO/C02 analyzer. The COX concentrations measured by both
methods were in good agreement with each other.
Dividing the sum of the CO and C02 concentrations at each temperature point
by the maximum sum at all temperatures to obtain the normalized COX concentration
at each temperature point, which are shown in FIG. 7 and indicate that the oxidization
initiation temperature of soot is lower when mixed with the material of formula
Na3.8K0.2A12Si2t0h9a n with 0.5 wt% Pt/A1203c atalyst and alone.
Example 8
Powders of Na3.8&.2A12Si209a nd NqA12Si209 (1 5 g each) were respectively
pre-mixed with 50 g iso-propanol (IPA) to form a slurry, followed by mixing them
with 150 g Yttrium stabilized zirconium (YSZ) milling balls (5 rnrn). After each
mixture was ball milled for one hour.
A monolith (length: 2.54 cm, diameter: 1.85 cm) was soaked into one slurry
for 30 seconds, which was dried in a flowing stream of air for 20 seconds, followed
by blasting hot air fiom a heat gun for about 1 minute. The process was repeated 4
times or more until visible inspection confirmed blockage of some channels in the
monolith. The weight gain was used to gauge the quantity of the catalyst deposited on
the porous monolith. Finally, the coated monolith was calcined at 550°C for 4 hours in
air.
Example 9
Each coated monolith (obtained in example 8) was loaded in a quartz tube of 1
inch OD and 0.75 inch ID. The two tubes were placed in a tube furnace. An empty
tube was also placed in the tube furnace.
A gas stream consisting 300 ppm of NO, 9% of 02, 7% of H20, ultra low
sulfur diesel (ULSD) vapor (C 1 :N = 6) and balanced with N2 (in volume) was allowed
to pass through the tube furnace. The gas hour space velocity (GHSV) was kept at
30,000 hr-'. The temperature of the tube furnace was ramped from 200 "C to 560 "C at
a rate of 20 "CI15 min.
0 The COX (CO+C02) concentration in the gas stream was measured by the
MultiGasTM 2030-HS High Speed Fourier Transform Infiared (FTIR) Gas Analyzer.
The total ULSD concentration in terms of C1 was measured by Horiba NDIR
CO/C02 analyzers after all ULSD was converted to COX by the diesel oxidation
catalyst (DOC) unit placed at the downstream of the FTIR gas analyzer. The COX
yield was calculated by dividing the COX concentration obtained from the FTIR
measurement by the COX concentration measured from the NDIR measurement.
FIG. 8 shows COX yield of the empty tube and the tubes with the monoliths. It
can be seen that ULSD gave 30% of COX yield at around 400 "C without catalyst but
the carnegieite catalysts (Na3.8K0.2A12Si20an9d Na4A12Si209)s howed some catalytic
performance in the presence of diesel.
While only certain features of the invention have been illustrated and
described herein, many modifications and changes will occur to those skilled in the
art. It is, therefore, to be understood that the appended claims are intended to cover
all such modifications and changes as fall within the true spirit of the invention.

We Claim:
1. A material of formula NaxMyA1,SibOs with Face Centered Cubic (fcc)
lattices forming F -4 3 m cubic structure, wherein
M is at least one of lithium, potassium, rubidium, caesium, vanadium,
chromium, iron, cobalt, nickel, ruthenium, rhodium, palladium, silver, osmium,
iridium, platinum, gold, and cerium;
OO;
11a13; 11b13; and 0<6132/3.
2. The material of claim 1, wherein y>O and M is at least one of potassium,
lithium, cerium, cobalt, iron and vanadium.
3. The material of claim 1, wherein 3.21x13.9996 and 0.00041yS0.8
4. The material of claim 1, wherein M is potassium and 3.25x13.8 and
0.21y10.8.
5. The material of claim 1, wherein M is lithium or cobalt and x=3.8 and
y=0.2.
6. The material of claim 1, wherein M is cerium and 3.81x13.9996 and
0.00041y<0.2.
7. The material of claim 1, being of formula: Na3.8&.2A12si2o9,
Na3.6K0.4A12Si209, Na3.2&.8A12Si209, Na3.8Lio.2A12Si209, Na3.8Ce0.2A12Si209.3,
Na3.998Ce0.002A12Si209.003, Na3.9996Ce0.0004A12Si209.0002, Na3.72K0.24A12Si1.9208.82 Or
Na3.8Co0.2A12Si209.2.
8. An exhaust gas system comprising the material of any of claims 1-7.
9. The exhaust gas system of claim 8, comprising a diesel particulate filter
for receiving diesel exhaust gas from a diesel engine and wherein the material is
coated on the diesel pariculate filter.
10. A method for using the material of any of claims 1-7, comprising:
contacting a carbonaceous material with an effective amount of the material of
claim 1 to initiate the oxidization of the carbonaceous material at a first oxidization
initiation temperature;
wherein the first oxidization initiation temperature is lower than an oxidization
initiation temperature of the carbonaceous material when a catalyst is not present.
11. The method of claim 10, wherein the contacting is in an environment
comprising an oxidant.
12. The method of claim 10, wherein the carbonaceous material comprises at
least one of carbon black, hydrocarbon and soot.