CU-SAPO MOLECULAR SIEVE, SYNTHESIS METHOD THEREFOR AND CATALYTIC USE THEREOF

Abstract

Disclosed are a Cu-SAPO molecular sieve with coexisting crystal phases of CHA and GME, a synthesis process therefor and the use thereof in a denitration reaction. A XRD diffraction pattern of the Cu-SAPO molecular sieve shows the characteristic of broad peaks and narrow peaks coexisting. An inorganic framework has the following chemical composition: wCu—(Si.sub.xAl.sub.yP.sub.z)O.sub.2, wherein x, y and z respectively represent the molar fractions of Si, Al and P; the molar fraction ranges thereof are respectively x=0.01˜0.28, y=0.35˜0.55 and z=0.28˜0.50, with x+y+z=1; w is the molar number of Cu per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2; and w=0.001˜0.124. The synthesized molecular sieve can be used as a catalyst for a selective reduction of NO.sub.x.

Claims

1. A copper-containing silicoaluminophosphate (SAPO) molecular sieve with coexisting crystal phases of CHA and GME, wherein the X-ray diffraction pattern of the molecular sieve comprises at least the following diffraction peaks: TABLE-US-00007 FWHM [2θ] No. 2θ (half-peak width) 1 7.40~7.56 0.15~0.35 2 9.20~9.70 0.25~0.65 3 12.80~12.92 0.06~0.09 4 15.80~16.21 0.15~0.40 5 17.60~17.82 0.05~0.11 6 20.30~20.90 0.15~0.40 7 21.75~22.05 0.06~0.09 8 25.65~26.05 0.05~0.09 9 30.11~30.96 0.20~0.45

2. The molecular sieve of claim 1, wherein an inorganic framework of the molecular sieve has the following chemical composition: wCu—(Si.sub.xAl.sub.yP.sub.z)O.sub.2, wherein x, y and z respectively represent the molar fractions of Si, Al and P, the molar fraction ranges thereof are respectively x=0.01˜0.28, y=0.35˜0.55 and z=0.28˜0.50 with x+y+z=1, w is the molar number of Cu per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, and w=0.001˜0.124.

3. The molecular sieve of claim 1, wherein the anhydrous chemical composition of the molecular sieve comprising a templating agent is expressed as wCu.Math.mR1.Math.nR3.Math.(Si.sub.xAl.sub.yP.sub.z)O.sub.2, wherein R1 is diisopropanolamine or diethanolamine, R3 is trimethylamine.sub.; m is the molar number of templating agent R1 per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, n is the molar number of templating agent R3 per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, m=0.01˜0.20, n=0.01˜0.10; x, y and z respectively represent the molar fractions of Si, Al and P, and the the molar fraction ranges thereof are respectively x=0.01˜0.28, y=0.35˜0.55 and z=0.28˜0.50 with x+y+z=1; w is the molar number of Cu per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, w=0.001˜0.124.

4. A method for synthesizing the molecular sieve of claim 1, comprising the steps of: a) mixing a copper source, deionized water, templating agents R1 and R2, a silicon source, an aluminum source and a phosphorus source in proportion to obtain an initial gel mixture having the following molar ratios:
Cu/Al.sub.2O.sub.3=0.01˜0.25;
SiO.sub.2/Al.sub.2O.sub.3=0.05˜2.0;
P.sub.2O.sub.5/Al.sub.2O.sub.3=0.5˜1.5;
H.sub.2O/Al.sub.2O.sub.3=8˜40;
R1/Al.sub.2O.sub.3=5˜20;
R2/Al.sub.2O.sub.3=0.1˜1.5; wherein R1 is diisopropanolamine (DIPA) or diethanolamine (DEOA); R2 is any one of trimethylamine (TMA), benzyltrimethylammonium chloride (BTACl), benzyltrimethylammonium hydroxide (BTAOH) or a mixture thereof; b) feeding the initial gel mixture obtained in step a) into a high pressure synthesis kettle, closing the kettle, heating to 160˜220° C. and performing crystallization for 5 to 72 hours; and c) after the crystallization is completed, separating a solid product, washing and drying to obtain the molecular sieve.

5. The method of claim 4, wherein in the step a), a mixing process is as follows: firstly mixing the copper source with water, then adding R1 and R2, stirring at room temperature for 0.5˜5 hours, then adding the aluminum source, the silicon source and the phosphorus source to the mixed solution, and stirring the mixed gel at room temperature for 1˜5 hours.

6. The method of claim 4, wherein in the step a), the silicon source is selected from one or more of silica sol, activated silica, orthosilicate and metakaolin; the aluminum source is selected from one or more of aluminum salt, activated alumina, pseudoboehmite, alkoxy aluminum and metakaolin; the phosphorus source is selected from one or more of orthophosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate, organic phosphorus compounds and phosphoric oxides; the copper source is selected from one or more of Cu(OAc).sub.2, CuSO.sub.4, Cu(NO.sub.3).sub.2 and CuCl.sub.2.

7. The method of claim 4, wherein in the step b), the crystallization is performed in a static or dynamic state.

8. The method of claim 4, wherein in the step a), the initial gel mixture has R1/Al.sub.2O.sub.3=5.0˜10.

9. The method of claim 4, wherein in the step a), the initial gel mixture has R2/Al.sub.2O.sub.3=0.25˜1.0.

10. A catalyst for NO.sub.x selective reduction, which is obtained by calcining the molecular sieve of claim 1 at 550˜700° C. in air.

11. The method for synthesizing the molecular sieve of claim 4, wherein an inorganic framework of the molecular sieve has the following chemical composition: wCu—(Si.sub.xAl.sub.yP.sub.z)O.sub.2, wherein x, y and z respectively represent the molar fractions of Si, Al and P, the molar fraction ranges thereof are respectively x=0.01˜0.28, y=0.35˜0.55 and z=0.28˜0.50 with x+y+z=1, w is the molar number of Cu per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, and w=0.001˜0.124.

12. The method for synthesizing the molecular sieve of claim 4, wherein the anhydrous chemical composition of the molecular sieve comprising a templating agent is expressed as wCu.Math.mR1.Math.nR3.Math.(Si.sub.xAl.sub.yP.sub.z)O.sub.2, wherein R1 is diisopropanolamine or diethanolamine, R3 is trimethylamine; m is the molar number of templating agent R1 per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, n is the molar number of templating agent R3 per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, m=0.01˜0.20, n=0.01˜0.10; x, y and z respectively represent the molar fractions of Si, Al and P, and the molar fraction ranges thereof are respectively x=0.01˜0.28, y=0.35˜0.55 and z=0.28˜0.50 with x+y+z=1; w is the molar number of Cu per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, w=0.001˜0.124.

13. The catalyst for NO.sub.x selective reduction of claim 10, wherein an inorganic framework of the molecular sieve has the following chemical composition: wCu—(Si.sub.xAl.sub.yP.sub.z)O.sub.2, wherein x, y and z respectively represent the molar fractions of Si, Al and P, the molar fraction ranges thereof are respectively x=0.01˜0.28, y=0.35˜0.55 and z=0.28˜0.50 with x+y+z=1, w is the molar number of Cu per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, and w=0.001˜0.124.

14. The catalyst for NO.sub.x selective reduction of claim 10, wherein the anhydrous chemical composition of the molecular sieve comprising a templating agent is expressed as wCu.Math.mR1.Math.nR3.Math.(Si.sub.xAl.sub.yP.sub.z)O.sub.2, wherein R1 is diisopropanolamine or diethanolamine, R3 is trimethylamine; m is the molar number of templating agent R1 per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, n is the molar number of templating agent R3 per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, m=0.01˜0.20, n=0.01˜0.10; x, y and z respectively represent the molar fractions of Si, Al and P, and the molar fraction ranges thereof are respectively x=0.01˜0.28, y=0.35˜0.55 and z=0.28˜0.50 with x+y+z=1; w is the molar number of Cu per mole of (Si.sub.xA;.sub.yP.sub.z)O.sub.2, w=0.001˜0.124.

15. A catalyst for NO.sub.x selective reduction, which is obtained by calcining molecular sieve synthesized according to the method of claim 4 at 550˜700° C. in air.

16. The catalyst for NO.sub.x selective reduction of claim 15, wherein an inorganic framework of the molecular sieve has the following chemical composition: wCu—(Si.sub.xA;.sub.yP.sub.z)O.sub.2, wherein x, y and z respectively represent the molar fractions of Si, Al and P, the molar fraction ranges thereof are respectively x=0.01˜0.28, y=0.35˜0.55 and z=0.28˜0.50 with x+y+z=1, w is the molar number of Cu per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, and w=0.001˜0.124.

17. The catalyst for NO.sub.x selective reduction of claim 15, wherein the anhydrous chemical composition of the molecular sieve comprising a templating agent is expressed as wCu.Math.mR1.Math.nR3.Math.(Si.sub.xAl.sub.yP.sub.z)O.sub.2, wherein R1 is diisopropanolamine or diethanolamine, R3 is trimethylamine.sub.; m is the molar number of templating agent R1 per mole of (Si.sub.xAl.sub.yR.sub.z)O.sub.2, n is the molar number of templating agent R3 per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, m=0.01˜0.20, n=0.01˜0.10; x, y and z respectively represent the molar fractions of Si, Al and P, and the molar fraction ranges thereof are respectively x=0.01˜0.28, y=0.35˜0.55 and z=0.28˜0.50 with x+y+z=1; w is the molar number of Cu per mole of (Si.sub.xAl.sub.yP.sub.z)O.sub.2, w=0.001˜0.124.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1 is a XRD pattern of a synthesized product in Example 1.

[0031] FIG. 2 is a scanning electron micrograph (SEM) of a synthetic product in Example 1.

[0032] FIG. 3 is an evaluation result of NH.sub.3-SCR reaction of Example 11 and Comparative Example 2.

[0033] FIG. 4 is an evaluation result of NH.sub.3-SCR reaction of catalysts with different copper contents (Examples 11-13).

[0034] FIG. 5 is a comparison of the evaluation results of NH.sub.3-SCR reaction before and after high-temperature hydrothermal treatment for the sample of Example 1 (Example 11 and Example 14)

[0035] FIG. 6 is a XRD result of samples corresponding to Comparative Examples 3-8.

DETAILED DESCRIPTION OF THE EMBODIMENT

[0036] The present invention will be futher described in combination with examples. It shoulde be understood that these examples are merely illustrative of the present application and are not to limit the scope of the present invention. The experimental methods which do not specify the specific conditions in the following examples are generally carried out according to conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in this application are purchased commercially and directly used without special treatment.

[0037] Unless otherwise specified, the test conditions used in the present application were as follows:

[0038] Elemental composition was measured using Magix 2424 X-ray fluorescence analyzer (XRF) from Philips.

[0039] FT-IR is collected using German BRUKER TENSOR 27 instrument.

[0040] X-ray powder diffraction phase analysis (XRD) was carried out on an X'Pert PRO X-ray diffractometer of PANalytical Corporation, Netherlands, using a Cu target, a Kα radiation source (λ=0.15418 nm), a voltage of 40 KV and a current of 40 mA.

[0041] The specific surface area and pore size distribution of the samples were determined using a Micromeritics ASAP Model 2020 physical adsorber. Before the analysis, the sample was vacuumized and heated at 350° C. for pretreating for 6 h, and the free volume of the sample tube was measured with He as the medium. When the sample was analyzed, the physical adsorption and desorption measurements were carried out at a liquid nitrogen temperature (77 K) using nitrogen as an adsorption gas. The specific surface area of the material was determined using the BET formula; the total pore volume of the material was calculated using the amount of adsorption of N.sub.2 at a relative pressure (P/P.sub.0) of 0.99. The micropore surface area and micropore volume were calculated by the t-plot method. When calculating, the cross-sectional area of the N.sub.2 molecule is 0.162 nm.sup.2.

[0042] SEM morphology analysis was performed using a Hitachi (SU8020) type scanning electron microscope.

[0043] Infinity plus 400WB solid nuclear magnetic resonance spectrum analyzer of Varian Corporation, U.S., is used in carbon nuclear magnetic resonance (.sup.13C MAS NMR) analys, with a BBO MAS probe and an operatinal magnetic field strength of 9.4T.

[0044] CHN elemental analysis was performed using a German-made Vario EL Cube elemental analyzer.

[0045] The invention is described in detail below by means of examples, but the present invention is not limited to these examples.

EXAMPLE 1

[0046] The molar ratio of each raw material and the crystallization conditions were shown in Table 2. The specific mixing process was as follows: firstly the copper source was mixed and dissolved with water, then R1 and R2 were added, and stirred at room temperature for 2 hours. Subsequently, an aluminum source, a silicon source and a phosphorus source were sequentially added to the mixed solution, and the mixed gel was stirred at room temperature for 5 hours to form a gel. The gel was transferred to a stainless steel reactor. After the reactor was placed in an oven, it was heated at a rate of 2° C./min to 200° C. for crystallization under rotation for 36 hours. After the crystallization was completed, the solid product was centrifuged, washed and dried in air at 100° C. to obtain a sample of the molecular sieve raw powder. The sample was subjected to XRD analysis, and the peak shape exhibited characteristics of broad peaks and narrow peaks. The XRD diffraction pattern was shown in FIG. 1, and the XRD diffraction data was shown in Table 3. After the sample was calcined and the template was removed, the specific surface area and pore volume are measured. The sample had a high BET specific surface area of 602 m.sup.2g.sup.−1 and a large pore volume of 0.27 cm.sup.3g.sup.−1, in which the specific pore surface area and micropore volume calculated according to the t-plot method were 533 M.sup.2g.sup.−1 and 0.26 cm.sup.3g.sup.−1 respectively.

[0047] The scanning electron micrograph of the obtained sample was shown in FIG. 2. It can be seen that the morphology of the obtained sample was in a circular sheet shape which was layered and stacked, and the particle size range was 3-5 μm.

TABLE-US-00002 TABLE 2 Molecular sieve synthesis ingredients and crystallization conditions Copper source and mole number Exam- Type and molar Type and molar of CuO ple No. amount of R1 amount of R2 contained 1 diethanolamine trimethylamine 0.009 molCuCl.sub.2 0.6 mol 0.03 mol 2 diethanolamine benzyltrimethylammonium 0.009 molCuSO.sub.4 0.5 mol chloride 0.01 mol 3 diisopropanolamine trimethylamine 0.006 molCu(NO.sub.3).sub.2 0.8 mol 0.12 mol 4 diethanolamine benzyltrimethylammonium 0.009 molCu(OAc).sub.2 1.2 mol chloride 0.095 mol 5 diethanolamine trimethylamine 0.009 molCuCl.sub.2 0.6 mol 0.015 mol 6 diethanolamine trimethylamine 0.009 molCuCl.sub.2 0.8 mol 0.06 mol 7 diethanolamine benzyltrimethylammonium 0.009 molCuCl.sub.2 1.0 mol hyderoxide 0.075 mol 8 diethanolamine trimethylamine 0.025 molCuCl.sub.2 0.6 mol 0.03 mol 9 diethanolamine trimethylamine 0.6 mol 0.03 mol Silicon Aluminum Phosphorus source source and source and and mole Crystal- mole number mole number number lization Crystal- Exam- of Al.sub.2O.sub.3 of P.sub.2O.sub.5 of SiO.sub.2 temper- lization ple No. contained contained contained H.sub.2O ature time 1 pseudoboehmite orthophosphoric Silica sol 1.5 mol 200° C. 36 h 0.1 mol acid 0.08 mol 0.08 mol 2 pseudoboehmite ammonium Silica sol 0.8 mol 170° C. 48 h 0.1 mol hydrogen 0.015 mol phosphate 0.05 mol 3 pseudoboehmite orthophosphoric Activated 1.1 mol 220° C. 5 h 0.1 mol acid silica 0.10 mol 0.08 mol 4 γ - alumina ammonium Silica sol 2.2 mol 170° C. 52 h 0.10 mol dihydrogen 0.06 mol phosphate 0.15 mol 5 pseudoboehmite ammonium Silica sol 1.8 mol 180° C. 50 h 0.1 mol dihydrogen 0.02 mol phosphate 0.12 mol 6 pseudoboehmite phosphoric Activated 1.5 mol 170° C. 40 h 0.1 mol anhydride silica 0.13 mol 0.06 mol 7 γ - alumina orthophosphoric Silica sol 2.0 mol 165° C. 60 h 0.1 mol acid 0.03 mol 0.10 mol 8 pseudoboehmite orthophosphoric Silica sol 1.5 mol 200° C. 36 h 0.1 mol acid 0.08 mol 0.08 mol 9 pseudoboehmite orthophosphoric Silica sol 1.5 mol 200° C. 36 h 0.1 mol acid 0.08 mol 0.08 mol

TABLE-US-00003 TABLE 3 XRD results of the sample in Example 1 No. 2θ d(Å) FWHM [2θ] 100 × I/I.sup.0 1 7.5332 11.73461 0.306 3.78 2 9.4392 9.36932 0.3328 16.7 3 12.8276 6.90145 0.0769 30.02 4 13.5764 6.52213 0.613 2.41 5 14.9902 5.91019 0.301 1.97 6 15.9732 5.54833 0.33542 17.36 7 17.6521 5.0242 0.0895 100 8 19.7388 4.49821 0.1534 8.02 9 20.5465 4.32274 0.2042 50.11 10 21.8947 4.05968 0.0769 43.13 11 22.3319 3.98041 0.0515 13.91 12 22.8456 3.89277 0.2047 4.33 13 24.9568 3.56792 0.4603 15.56 14 25.852 3.44654 0.067 51.61 15 27.5942 3.23261 0.2556 6.68 16 30.5503 2.92623 0.2305 33.11 17 31.4892 2.83871 0.0628 15.19 18 33.192 2.69914 0.4088 3.1 19 34.4342 2.60441 0.0519 19.26 20 35.583 2.52287 0.5116 2.9 21 39.3457 2.29004 0.634 2.01 22 42.6011 2.12223 0.0765 11.02 23 43.3283 2.08657 0.072 8.95 24 47.5951 1.90894 0.0932 10.18 25 48.6442 1.87181 0.4093 3.11 26 50.5224 1.80502 0.0936 20.97 27 50.6481 1.80533 0.075 11.88 28 53.192 1.72051 0.1096 9.48 29 54.151 1.69223 0.072 8.1 30 54.9008 1.67102 0.076 11.21 31 55.9254 1.64276 0.2498 2.42 32 59.4243 1.55415 0.9988 1.11 33 60.9672 1.51848 0.2493 2.01 34 61.6477 1.50332 0.2497 2.63 35 62.6378 1.48193 0.3744 1.15

EXAMPLE 2

[0048] The specific proportion of ingredients and crystallization conditions were shown in Table 2, and the specific mixing process was the same as that of Example 1.

[0049] The synthesized samples were subjected to XRD analysis, and representative data results were shown in Table 4.

[0050] Scanning electron micrographs showed that the morphology of the obtained sample to was similar to that of the sample of Example 1.

TABLE-US-00004 TABLE 4 XRD results of the sample of Example 2 FWHM [2θ] No. 2θ (half-peak width) 1 7.403 0.156 2 9.207 0.632 3 12.801 0.072 4 15.807 0.381 5 17.601 0.052 6 20.302 0.388 7 21.754 0.084 8 25.688 0.085 9 30.1143 0.434

EXAMPLE 3

[0051] The specific proportion of ingredients and crystallization conditions were shown in Table 2, and the specific mixing process was the same as that of Example 1.

[0052] The synthesized samples were subjected to XRD analysis, and representative data results were shown in Table 5.

[0053] Scanning electron micrographs showed that the morphology of the obtained sample was similar to that of the sample of Example 1.

TABLE-US-00005 TABLE 5 XRD results of the sample in Example 3 FWHM [2θ] No. 2θ (half-peak width) 1 7.556 0.331 2 9.623 0.256 3 12.911 0.068 4 16.203 0.157 5 17.812 0.102 6 20.884 0.153 7 22.015 0.075 8 26.031 0.074 9 30.941 0.207

EXAMPLES 4-9

[0054] The specific proportion of ingredients and crystallization conditions were shown in Table 2, and the specific mixing process was the same as in Example 1.

[0055] The synthesized samples were subjected to XRD analysis. The results of XRD data of Examples 4 and 9 were similar to those of Table 3. The results of XRD data of Examples 5 and 6 were similar to those of Table 4, and the results of XRD data of Examples 7 and 8 were close to Table 5.

[0056] By comparing with the diffraction spectrum of the different proportions of to GME/CHA symbiotic silicon-aluminum zeolite crystal phase given on the official website of the International Zeolite Association, the content of CHA crystal phase in the silicon-phosphorus-aluminum molecular sieve provided in Examples 1-9 was significantly higher than that of GEM crystal phase.

EXAMPLE 10

[0057] .sup.13C MAS NMR analysis of the powder samples of Examples 1-9 was carried out. Compared with .sup.13C MAS NMR standard spectrum of diisopropanolamine, diethanolamine and trimethylamine, it was found that the samples synthesized by using diisopropanolamine as a solvent had resonance peaks of diisopropanolamine and trimethylamine, and the samples synthesized by using diethanolamine as a solvent had resonance peaks of diethanolamine and trimethylamine. Quantitative analysis was performed based on the specific non-coincident NMR peaks of the two substances to determine the ratio of the two substances.

[0058] Bulk elemental composition of the molecular sieve product was performed by XRF analysis, and CHN eletmental analysis was also conducted on the raw powder of Examples 1-9. The composition of the molecular sieve raw powder obtained by comprehensive CHN elemental analysis, XRF and .sup.13C MAS NMR analysis, was shown in Table 6.

TABLE-US-00006 TABLE 6 Composition of the raw powder samples in Examples 1-9 Example Composition of the raw powder samples 1 0.038Cu0.07DEOA0.02TMA(Si.sub.0.203Al.sub.0.470P.sub.0.327)O.sub.2 2 0.008Cu0.04DEOA0.01TMA(Si.sub.0.032Al.sub.0.490P.sub.0.478)O.sub.2 3 0.029Cu0.081DIPA0.058TMA(Si.sub.0.205Al.sub.0.488P.sub.0.307)O.sub.2 4 0.040Cu0.13DEOA0.048TMA(Si.sub.0.165Al.sub.0.488P.sub.0.347)O.sub.2 5 0.018Cu0.07DEOA0.02TMA(Si.sub.0.072Al.sub.0.470P.sub.0.458)O.sub.2 6 0.035Cu0.11DEOA0.034TMA(Si.sub.0.155Al.sub.0.488P.sub.0.357)O.sub.2 7 0.020Cu0.12DEOA0.038TMA(Si.sub.0.100Al.sub.0.488P.sub.0.412)O.sub.2 8 0.09Cu0.07DEOA0.02TMA(Si.sub.0.203Al.sub.0.470P.sub.0.327)O.sub.2 9 0.07DEOA0.02TMA(Si.sub.0.203Al.sub.0.470P.sub.0.327)O.sub.2

[0059] The raw powder samples of Examples 1-9 were separately ground and pressed with potassium bromide and subjected to FT-IR characterization. They all showed a characteristic vibration absorption peak attributed to the double six-membered ring at 637 cm.sup.−1, showing the presence of a double six-membered ring in the sample.

EXAMPLE 11

[0060] The sample obtained in Example 1 was calcined at a high temperature of 650° C. for 2 hours. After the templating agent was removed, the catalytic performance for the selective catalytic reduction of NO.sub.x by NH.sub.3 was evaluated. The specific experimental procedures and conditions were as follows: after calcination, the sample was tableted and sieved. 0.1 g of 60-80 mesh of the sample was weighed and mixed with 0.4 g of quartz (60-80 mesh), and charged into a fixed bed reactor. The catalysts was purged by nitrogen at 600° C. for 40 min, then the temperature was lowered to 120° C. to start the evaluation, and the temperature was raised to 550° C. step by step. The component of the raw gas was: NO: 500 ppm, NH.sub.3: 500 ppm, O.sub.2: 5%, H.sub.2O: 5%, N.sub.2 as a balance gas, and a gas flow rate of 300 mL/min. The reaction tail gas was analyzed by online FTIR using a Bruker Tensor 27 instrument. The results were shown in FIG. 3 and FIG. 4. It can be seen that the conversion of NO was 77% at 150° C., and the conversion of NO was higher than 90% over a wide temperature range of 180-450° C. Similarly, the samples obtained in Examples 2-8 exhibited excellent catalytic performance for selective reduction of NO, after the same treatment as that of the sample of Example 1.

EXAMPLE 12

[0061] The sample obtained in Example 3 was calcined at a high temperature of 650° C. for 2 hours. After the templating agent was removed, the catalytic performance for the NH.sub.3 selective reduction of NO.sub.x reaction was characterized. The specific experimental procedures and conditions were as follows: after calcination, the sample was tableted and sieved. 0.1 g of 60-80 mesh of the sample was weighed and mixed with 0.4 g of quartz (60-80 mesh), and charged into a fixed bed reactor. The catalysts was purged by nitrogen at 600° C. for 40 min, then the is temperature was lowered to 120° C. to start the evaluation, and the temperature was raised to 550° C. step by step. The component of the raw gas was: NO: 500 ppm, NH.sub.3: 500 ppm, O.sub.2: 5%, H.sub.2O: 5%, N.sub.2 as a balance gas, and a gas flow rate of 300 mL/min. The reaction tail gas was analyzed by online FTIR using a Bruker Tensor 27 instrument. The reaction results were shown in FIG. 4.

EXAMPLE 13

[0062] The sample obtained in Example 8 was calcined at a high temperature of 650° C. for 2 hours. After the templating agent was removed, the catalytic performance for the NH.sub.3 selective reduction of NO.sub.x reaction was characterized. The specific experimental procedures and conditions were as follows: after calcination, the sample was tableted and sieved. 0.1 g of 60-80 mesh of the sample was weighed and mixed with 0.4 g of quartz (60-80 mesh), and charged into a fixed bed reactor. The catalysts was purged by nitrogen at 600° C. for 40 min, then the temperature was lowered to 120° C. to start the evaluation, and the temperature was raised to 550° C. step by step. The component of the raw gas was: NO: 500 ppm, NH.sub.3: 500 ppm, O.sub.2: 5%, H.sub.2O: 5%, N.sub.2 as a balance gas, and a gas flow rate of 300 mL/min. The reaction tail gas was analyzed by online FTIR using a Bruker Tensor 27 instrument. The reaction results were shown in FIG. 4.

EXAMPLE 14

[0063] The sample obtained in Example 1 was calcined at a high temperature of 650° C. for 2 hours. After the templating agent was removed, hydrothermal aging treatment was performed at 800° C., the content of water vapor was 100%, and the treatment time was 24 hours. It was dried at 100° C. after the treatment.

[0064] The relative crystallinity of the sample was determined by XRD method, and the crystallinity of the sample was 95% compared with Example 1, indicating that the sample prepared in Example 1 had high hydrothermal stability, the integrity of the structure of the sample can be well maintained after water treatment.

[0065] The catalytic performance for NH.sub.3 selective reduction of NO.sub.x reaction was characterized. The specific experimental procedures and conditions were as follows: after calcination, the sample was tableted and sieved. 0.1 g of 60-80 mesh of the sample was weighed and mixed with 0.4 g of quartz (60-80 mesh), and charged into a fixed bed reactor. The catalysts was purged by nitrogen at 600° C. for 40 min, then the temperature was lowered to 120° C. to start the evaluation, and the temperature was raised to 550° C. step by step. The component of the raw gas was: NO: 500 ppm, NH.sub.3: 500 ppm, O.sub.2: 5%, H.sub.2O: 5%, N.sub.2 as a balance gas, and a gas flow rate of 300 mL/min. The reaction tail gas was analyzed by online FTIR using a Bruker Tensor 27 instrument. The reaction results were shown in FIG. 5.

COMPARATIVE EXAMPLE 1

[0066] 10 g of the sample molecular sieve raw powder obtained in Example 9 was used as a precursor, and was heated at a rate of 2° C./min to a constant temperature of 600° C. for 4 hours to remove the organic templating agent and water contained therein.

[0067] The calcined sample was put into a 3.66 mol/L ammonium nitrate aqueous solution at a solid-liquid ratio (mass ratio) of 1:10, stirred for 5 minutes, and then heated to 80° C. for ion exchange for 2 hours. After being centrifugaed and washed for three times with deionized water and dried at 80° C., a NH4.sup.+ molecular sieve was obtained.

[0068] 7 g of NH4.sup.+ molecular sieve was put into a 0.03 mol/L Cu(CH.sub.3COO).sub.2.H.sub.2O solution at a solid-liquid ratio of 1:25. After being stirred for 5 minutes, the mixture was heated to 50° C. to ion exchange for 4 hours. After being centrifugaed and washed for three times with deionized water and dried at 80° C., an obtained sample was denoted as Cu-9/T. The XRF elemental analysis showed that the product had a copper oxide content of 3.2%, which was close to that of Example 1. The specific surface area and pore volume of the calcined type Example 9 and the Cu-9/T sample were measured by N.sub.2 physical adsorption, and the specific pore surface area and pore volume were calculated by the t-plot method. The micropore specific surface area and micropore volume of the sample of Example 9 were 559 m.sup.2g.sup.−1 and 0.28 cm.sup.3g.sup.−1, respectively. The micropore specific surface area and micropore volume of the Cu-9/T sample were 520 m.sup.2g.sup.−1 and 0.25 cm.sup.3g.sup.−1, respectively. These results show that the catalyst prepared according to the method of Example 1 can better maintain the regularity of framework structure of the sample.

COMPARATIVE EXAMPLE 2

[0069] The sample obtained in Comparative Example 1 was calcined at a high temperature of 650° C. for 2 hours, and used as a catalyst for NH.sub.3 selective reduction of NO.sub.x reaction. The specific experimental procedures and conditions were as follows: after calcination, the sample was tableted and sieved. 0.1 g of 60-80 mesh of the sample was weighed and mixed with 0.4 g of quartz (60-80 mesh), and charged into a fixed bed reactor. The catalysts was purgedby nitrogen at 600° C. for 40 min, then the temperature was lowered to 120° C. to start the evaluation, and the temperature was raised to 550° C. step by step. The component of the raw gas was: NO: 500 ppm, NH.sub.3: 500 ppm, O.sub.2: 5%, H.sub.2O: 5%, N.sub.2 as a balance gas, and the total gas flow rate was 300 mL/min. The total space velocity of the reaction was GHSV=180000 h.sup.−1. The reaction tail gas was analyzed by online FTIR using a Bruker Tensor 27 instrument. The specific results were shown in FIG. 3.

COMPARATIVE EXAMPLE 3

[0070] The molar ratio of the specific ingredients, the raw materials and the crystallization conditions were the same as that of Example 1, except that the diethanolamine in the raw material was replaced with triethylamine. The synthesized sample was SAPO-34 molecular sieve, and the XRD analysis results were shown in FIG. 6.

COMPARATIVE EXAMPLE 4

[0071] The molar ratio of the specific ingredients, the raw materials and the crystallization conditions were the same as that of Example 2, except that the benzyltrimethylammonium hyderoxide in the raw material was replaced with 1,6-hexanediamine. The synthesized sample was a lamellar phase, and the XRD results were shown in FIG. 6.

COMPARATIVE EXAMPLE 5

[0072] The molar ratio of the specific ingredients, the raw materials and the crystallization conditions were the same as that of Example 3, except that the addition of trimethylamine in the raw materials was omitted. The synthesized sample was a physical mixture of SAPO-34 and SAPO-5, and the XRD results were shown in FIG. 6.

COMPARATIVE EXAMPLE 6

[0073] The molar ratio of the specific ingredients, the raw materials and the crystallization conditions were the same as that of Example 4, except that the diethanolamine in the raw is material was replaced with diethylamine. The synthesized sample was a physical mixture of DNL-6 (SAPO molecular sieve with RHO structure) with a small amount of SAPO-34, and the XRD results were shown in FIG. 6.

COMPARATIVE EXAMPLE 7

[0074] The molar ratio of the specific ingredients, the raw materials and the crystallization conditions were the same as as that of Example 5, except that the trimethylamine in the raw material was replaced with triethanolamine. The synthesized sample was a physical mixture of SAPO-5 and SAPO-34, and the XRD results were shown in FIG. 6.

COMPARATIVE EXAMPLE 8

[0075] The molar ratio of the specific ingredients, the raw materials and the crystallization conditions were the same as that of Example 5, except that the addition of trimethylamine in the raw materials was omitted. The synthesized sample was amorphous, and the XRD analysis results were shown in FIG. 6.

[0076] The results of the synthesis of Comparative Examples 3-8 showed that the Cu-SAPO molecular sieve with coexisting crystal phases of CHA and GME of the present patent application can be obtained only under a specific combination of templating agents and suitable crystallization conditions.

[0077] While the present application has been described above with reference to preferred embodiments, but these embodiments are not intended to limit the claims. Without departing from the spirit of the present application, people skilled in the art will be able to make several possible variations and modifications and thus the protection scope shall be determined by the scope as defined in the claims.