CN1843914A - Silicon-aluminium molecular sieve with MWW structure and preparation method thereof - Google Patents

Abstract

The invention discloses a silica-alumina molecular screen of MWW structure, and it is characterized in that the molar composition of raw material is xR:yLi2O:zAl2O3:SiO2, which is represented in waterless oxide compound way, and XRD spectrogram contains at least diffraction peak data in table 1; and the molar composition after baking is yLi2O:zAl2O3:SiO2, and XRD spectrogram contains at least diffraction peak data in table 2; R is mould agent hexamethylene diamine, x=0.01-0.5, y=0.0001-0.5, and z=0.03-0.5. The said molecular screen employs lithium hydrate as alkali and lithium ion as ion source and it is can be used as active component or carrier for catalyst.

Description

A kind of MWW structure Si-Al molecular sieve and preparation method thereof

Technical field the invention relates to a kind of Si-Al molecular sieve and preparation method thereof, more specifically says so about a kind of MWW structure Si-Al molecular sieve and preparation method thereof.

Background technology

Zeolite molecular sieve is made up of silicon-oxy tetrahedron and aluminum-oxygen tetrahedron and balance cation.Zeolite molecular sieve has been widely used in every field such as catalysis, absorption and ion-exchange, but the duct of acidity that its outstanding advantage is a modulation and different size and hole play select the shape effect.

MCM-22, MCM-49 and MCM-56 molecular sieve are defined as the MWW type by international zeolite federation (IZA), and they belong to laminate structure together, and interlayer links to each other with oxo bridge, the pore canal system that have two kinds of independences, is not connected each other.

USP4,954,325 disclose MCM-22 molecular sieve and synthetic method thereof, and used template is a hexamethylene imine, and SiO feeds intake ₂/ Al ₂O ₃Mol ratio is 10～80, selects 10～60 usually, and is preferred 20～40, but in an embodiment, used alkali source is NaOH all, and SiO feeds intake ₂/ Al ₂O ₃Be 30.

USP5,236,575 disclose MCM-49 molecular sieve and synthetic method thereof, and the difference with the MCM-22 molecular sieve wherein also has been described.The synthetic used template of MCM-49 molecular sieve also is a hexamethylene imine, and SiO feeds intake ₂/ Al ₂O ₃Mol ratio selects 10～35 usually less than 35, and preferred 15～31.In an embodiment, used alkali source is NaOH all, and SiO feeds intake ₂/ Al ₂O ₃Between 23～33.34.XRD data before and after the roasting of MCM-49 molecular sieve are constant substantially, XRD data after the roasting of MCM-22 molecular sieve are identical substantially with the MCM-49 molecular sieve, d=13.5_ of its former powder (2 θ=6.55 °) and 6.75_ (2 θ=13.11 °) diffraction peak, after roasting, disappear substantially, but very little acromion occurs at d=12.6_, strong diffraction peak occurs at 6.18_ simultaneously.

In " J.Phys.Chem., 1996, Vol.100, No.9,3790 ", the difference of the XRD data before and after the MCM-22 molecular sieve roasting also has been described, and with the difference of the XRD data of MCM-49 molecular sieve.2 θ at (002) peak of MCM-22 molecular screen primary powder are 6.53 °, after roasting, move to 6.94 °, almost overlap for 7.17 ° with the diffraction peak of (100) crystal face, 2 θ at (004) peak of former powder are 13.26 °, after roasting, move to 14.06 °, almost overlap for 14.36 ° with the diffraction peak of the remarkable enhanced of intensity (200) crystal face; Preceding 2 θ of roasting=26.2 ° are unimodal, in the high angle side hangover are arranged, and three peaks then appear in MCM-22 molecular sieve after the roasting and MCM-49 molecular sieve between 2 θ=26.5-29.0 °.

USP5,362,697 and USP5,827,491 have reported MCM-56 molecular sieve and synthetic method thereof, used template is a hexamethylene imine.SiO feeds intake ₂/ Al ₂O ₃Mol ratio selects 10～20 usually less than 35, and preferred 13～18.In an embodiment, used alkali source is NaOH all, and SiO feeds intake ₂/ Al ₂O ₃Mol ratio is between 15～23.

Summary of the invention

The contriver is surprised to find that when being template with the hexamethylene imine equally, adopting lithium hydroxide is alkali source and Li ⁺During ion source, prepared Si-Al molecular sieve has XRD spectra unique, that be different from MCM-22, MCM-49 and MCM-56 molecular sieve, and it has good catalytic performance during as benzene and ethylene alkylation catalytic material.

Therefore, one of purpose of the present invention provides a kind of MWW structure Si-Al molecular sieve with unique XRD spectra feature, and two of purpose is to provide the preparation method of described MWW structure Si-Al molecular sieve.

MWW structure Si-Al molecular sieve provided by the invention, the mole that the former powder that it is characterized in that this molecular sieve is represented with the anhydrous oxide form consists of xR: yLi ₂O: zAl ₂O ₃: SiO ₂, XRD spectra contains the diffraction peak data of table 1 at least, and the mole of representing with the anhydrous oxide form after the roasting consists of yLi ₂O: zAl ₂O ₃: SiO ₂, XRD spectra contains the diffraction peak data of table 2 at least, and wherein, R is the template hexamethylene imine, x=0.01～0.5, preferred 0.05～0.4, most preferably 0.08～0.2; Y=0.0001～0.5, preferred 0.001～0.4, most preferably 0.03～0.2; Z=0.03～0.5, preferred 0.04～0.4, most preferably 0.05～0.3.

In table 1 and table 2, W, M, S and VS represent the relative intensity of diffraction peak, W=0～20, M=20～40, S=40～60, VS=60～100.

Table 1

2θ(°)	d(_)	I/I 0
			6.20-6.34	14.25-13.94	VS
7.02-7.16	12.59-12.34	S-VS
			7.69-7.83	11.49-11.29	M-S
9.33-9.53	9.48-9.28	M
			12.64-12.75	7.00-6.94	W-M
14.17-14.33	6.25-6.18	W
			14.47-14.62	6.12-6.06	W
15.54-15.66	5.70-5.66	W
			18.68-19.08	4.75-4.65	W
19.68-20.04	4.51-4.43	M
			21.41-21.52	4.15-4.13	W-M
21.63-21.78	4.11-4.08	W-M
			22.27-22.50	3.99-3.95	W-M
23.27-23.53	3.82-3.78	W
			24.79-24.93	3.59-3.57	M
25.82-25.97	3.45-3.43	S-VS
			26.60-26.76	3.35-3.33	M
27.95-28.32	3.19-3.15	W
			28.89-29.08	3.09-3.07	W
31.27-31.53	2.86-2.84	W
			32.80-33.04	2.73-2.71	W
34.35-34.90	2.61-2.57	W
			37.46-37.79	2.40-2.38	W

Table 2

2θ(°)	d(_)	I/I 0
			7.09-7.17	12.46-12.33	VS
7.91-7.99	11.17-11.06	VS
			9.93-10.03	8.90-8.82	VS
12.79-12.90	6.92-6.86	W
			14.28-14.35	6.20-6.17	M
14.69-14.74	6.03-6.01	W
			15.91-15.96	5.57-5.55	W-M
18.96-19.04	4.68-4.66	W
			20.08-20.27	4.42-4.38	M
21.05-21.16	4.22-4.20	M
			21.51-21.65	4.13-4.10	M
21.78-21.89	4.08-4.06	M-S
			22.62-22.79	3.93-3.90	VS
23.59-23.72	3.77-3.75	M-S
			24.86-25.01	3.58-3.56	W-M
25.89-26.05	3.44-3.42	VS
			26.85-27.01	3.32-3.30	M
27.61-27.78	3.23-3.21	M
			28.42-28.60	3.14-3.12	W-M
31.38-31.61	2.85-2.83	W
			32.07-32.31	2.79-2.77	W
33.17-33.43	2.70-2.68	W
			34.08-34.35	2.63-2.61	W

In the Si-Al molecular sieve provided by the invention, said roasting, its condition is that those skilled in the art is known, generally carries out in the air of 300～700 ℃ of current downflow or rare gas element, the present invention there is no special requirement to this.In embodiment thereafter, maturing temperature is all at 550 ℃, but therefore and restriction this

The content of invention.

The typical XRD spectrum of sample as depicted in figs. 1 and 2 after former powder sample of MWW structure Si-Al molecular sieve provided by the invention and the roasting.The XRD spectra of MCM-22, MCM-49, MCM-56 molecular sieve also lists file names with, and with this difference that compares them, wherein the MCM-22 molecular sieve is by USP4,954,325 embodiment, 1 synthetic sample; The MCM-49 molecular sieve is by USP5,236,575 embodiment, 3 synthetic samples; The MCM-56 molecular sieve is by USP5,362,697 embodiment, 1 synthetic sample.

By Fig. 1 and Fig. 2 as can be known, the diffraction peak of MCM-56 molecular sieve (curve D) is few and all be the broadening diffuse peaks basically.101 crystal face peaks (2 θ=7.8 ° about) and 102 crystal face peaks (2 θ=9.5 ° about) overlap, and illustrates that layer is very general with the staggered floor of interlayer, its spectrogram variation before and after roasting not quite, the position at all peaks, intensity and peak shape all do not change.MCM-22 molecular sieve (curve A) also has more diffuse peaks, but peak height is higher, the diffracted intensity height, and 101,102 crystal face peaks separate fully, crystal face peak, 002 (2 θ=6.5 ° about) and 100 (2 θ=7.1 ° about) is separated, and 2 θ have only a long tailing peak behind 25.9 ° of main peaks.MCM-49 molecular sieve (curve C) does not have the peak about 2 θ=6.5 °, the further feature peak is much more sharp-pointed than the MCM-22 molecular sieve, and symmetry of crystals is better than MCM-22 molecular sieve and MCM-56 molecular sieve.But the XRD spectra of MCM-22 molecular sieve is the same substantially with the MCM-49 molecular sieve after the roasting, and sharpening has all appearred in the broad peak in its former powder after roasting, becomes more stable crystalline phase by not really stable crystal transition.

There is certain difference in MWW Si-Al molecular sieve provided by the invention (being called for short the M molecular sieve, the curve B of seeing Fig. 1 and Fig. 2) with the XRD spectrum of MCM-22 molecular screen primary powder and MCM-49 molecular screen primary powder.One, 002 crystal face peak of M molecular sieve separates with 100 crystal face peaks fully to low angle skew (about d=6.3 °), and resolution is greater than the MCM-22 molecular sieve, and MCM-49 molecular sieve then two peaks overlaps substantially; Its two, the MCM-22 molecular screen primary powder is a broadening diffuse peaks at 22-24 ° of peak, and division has appearred in the M molecular sieve, and the peak is more sharp-pointed, but the peak about 24 ° does not separate fully as the MCM-49 molecular sieve; They are three years old, be a small peak behind 25.9 ° of main peaks of MCM-22 molecular screen primary powder and long hangover is arranged, the MCM-49 molecular sieve then is uniform 3 small peaks in interval, the M molecular sieve also is 3 small peaks, just the position of latter two small peak has been offset to high angle, and above situation has illustrated that there are difference in the former powder of MWW structure Si-Al molecular sieve provided by the invention and the space structure of MCM-22 molecular sieve and MCM-49 molecular sieve.The basic indifference of the XRD spectra of sample and MCM-22 and MCM-49 after the roasting illustrates that it is the MWW structure molecular screen.

The present invention also provides the preparation method of said MWW structure Si-Al molecular sieve, and this method is to be alkali source and Li with the lithium hydroxide ⁺Ion source prepares molecular sieve, it is characterized in that silicon source, aluminium source, lithium hydroxide, hexamethylene imine and deionized water are mixed into glue, and its mole consists of aR: bLiOH: cAl ₂O ₃: SiO ₂: dH ₂O, crystallization 2～200 hours and reclaim product under 120～220 ℃ and autogenous pressure then.Wherein, R is a hexamethylene imine, a=0.05～1.0, preferred 0.1～0.8, more preferably 0.2～0.6; B=0.01～0.5, preferred 0.05～0.4, more preferably 0.1～0.3; C=0.03～0.5, preferred 0.04～0.4, more preferably 0.05～0.3; D=2～100, preferred 5～80, more preferably 10～40, said silicon source is selected from solid silicone, silicic acid or silicon sol, and the aluminium source is selected from aluminum oxide, aluminium hydroxide or hydrated aluminum oxide, and preferred aluminium source is a pseudo-boehmite, in addition, amorphous silicic aluminium also can be used as common silicon source and use in the aluminium source.

The process of said recovery product be with crystallization product after filtration, washing, drying obtain the process of former powder, this process is well known to those skilled in the art, the present invention is to this and have no special requirements.

After MWW structure Si-Al molecular sieve provided by the invention exchanges through ammonium salt, become the product of Hydrogen through roasting, has strongly-acid, can be used as the carrier of activity of such catalysts constituent element or catalyzer, be used for the conversion reaction of catalytic cracking, hydrocracking, hydrotreatment, alkylating aromatic hydrocarbon, hydrocarbon isomerization, oxygen-containing organic compound such as methyl alcohol, dme, also but transition metal or precious metal in the load are made dual-function catalyst.

Description of drawings

Fig. 1 is the XRD spectra of molecular screen primary powder sample.

Fig. 2 is the XRD spectra of sample after the molecular sieve roasting.

Embodiment

Below by embodiment and Comparative Examples the present invention is further described, but does not therefore limit this

The content of invention.

Embodiment 1

With 16.8gLiOHH ₂O (Beijing Yili Fine Chemicals Co., Ltd., analytical pure, butt: 90wt%) be dissolved in 613.1gH ₂Among the O, add 59.4g pseudo-boehmite (Qilu Petrochemical company catalyst plant, industrial goods, Al while stirring ₂O ₃: 70wt%) with 462.0g silicon sol (Beijing flying dragon equine trade company limited, SiO ₂: 26wt%), add 100g hexamethylene imine (being called for short HMI) again and be mixed into gel, stir.Gained mixture mole consists of aR: bLiOH: cAl ₂O ₃: SiO ₂: dH ₂O=0.5: 0.18: 0.2: 1: 27.Gel was gone in the stainless steel sealed reactor under 170 ℃ and autogenous pressure dynamic crystallization 100 hours.Product is through cooling, filtration, washing and dry.Diffraction data sees Table 3, and the mole that the anhydrous oxide form is represented consists of 0.159R: 0.101Li ₂O: 0.223Al ₂O ₃: SiO ₂Roasting is after 4 hours under 550 ℃ of fluidizing airs with sample, and diffraction data sees Table 4, and the mole that the anhydrous oxide form is represented consists of 0.107Li ₂O: 0.220Al ₂O ₃: SiO ₂

Table 3

2θ(°)	d(_)	I/I 0
			6.21	14.229	92
7.05	12.535	100
			7.70	11.478	39
9.33	9.476	27
			12.64	7.001	13
14.25	6.214	9
			14.50	6.107	7
15.57	5.690	9
			18.89	4.697	16
19.83	4.476	32
			21.41	4.149	19
21.66	4.102	24
			22.31	3.984	39
23.40	3.801	14
			24.82	3.586	23
25.87	3.443	61
			26.65	3.344	34
28.11	3.174	15
			29.00	3.078	10
31.36	2.852	4
			32.89	2.722	3
34.45	2.603	7
			37.68	2.387	7

Table 4

2θ(°)	d(_)	I/I 0
			7.16	12.343	100
7.98	11.076	60
			10.02	8.825	62
12.90	6.861	11
			14.35	6.171	33
14.69	6.028	12
			15.96	5.552	16
18.99	4.672	5
			20.25	4.384	16
21.16	4.198	9
			21.65	4.104	17
21.88	4.061	23
			22.75	3.908	36
23.72	3.750	21
			24.97	3.565	16
25.99	3.427	61
			26.99	3.303	19
27.75	3.214	17
			28.57	3.123	14
31.59	2.831	3
			32.21	2.778	4
33.38	2.684	8
			34.30	2.614	3

Comparative Examples 1

16.7gNaOH (Beijing Yili Fine Chemicals Co., Ltd., analytical pure) is dissolved in 729.6gH ₂Among the O, add 29.7g pseudo-boehmite and 462.0g silicon sol while stirring, add the 100.0g hexamethylene imine again and be mixed into gel, stir.Gained mixture mole consists of aR: bNaOH: cAl ₂O ₃: SiO ₂: dH ₂O=0.5: 0.2: 0.1: 1: 30.Gel was gone in the stainless steel sealed reactor under 150 ℃ and autogenous pressure the dynamic agitation crystallization 60 hours.Product is through cooling, filtration, washing and dry, and former powder records thing through the XRD sign and is mordenite mutually.

This Comparative Examples explanation (SiO when the silica alumina ratio that feeds intake is very low ₂/ Al ₂O ₃=10), be under the condition of alkali source with NaOH, the synthetic molecular sieve is a mordenite, and can not synthesize the MWW molecular sieve.

Embodiment 2

With 18.6gLiOH.H ₂O is dissolved in 729.6gH ₂Among the O, add 29.7g pseudo-boehmite and 462.0g silicon sol while stirring, add the 100g hexamethylene imine again and be mixed into gel, stir.Gained mixture mole consists of aR: bLiOH: cAl ₂O ₃: SiO ₂: dH ₂O=0.5: 0.2: 0.1: 1: 30.Gel is gone in the stainless steel sealed reactor to descend to stir crystallization 60 hours with autogenous pressure in 150 ℃.Product is through cooling, filtration, washing and dry, and diffraction data sees Table 5, and the mole that the anhydrous oxide form is represented consists of 0.119R: 0.098Li ₂O: 0.122Al ₂O ₃: SiO ₂Roasting is after 4 hours under 550 ℃ of fluidizing airs with sample, and diffraction data sees Table 6, and the mole that the anhydrous oxide form is represented consists of 0.101Li ₂O: 0.123Al ₂O ₃: SiO ₂

Table 5

2θ(°)	d(_)	I/I 0
			6.28	14.070	67
7.16	12.343	100
			7.83	11.288	41
9.52	9.288	37
			12.74	6.946	18
14.31	6.188	11
			14.62	6.057	9
15.63	5.668	12
			19.03	4.662	19
20.00	4.438	25
			21.52	4.128	16
21.77	4.081	20
			22.42	3.964	41
23.40	3.801	14
			24.91	3.573	22
25.93	3.435	58
			26.71	3.337	34
28.19	3.165	17
			29.03	3.075	10
31.52	2.838	4
			32.96	2.717	3
34.49	2.600	6
			37.79	2.380	7

Table 6

2θ(°)	d(_)	I/I 0
			7.10	12.447	100
7.93	11.146	71
			9.98	8.860	87
12.80	6.914	8
			14.28	6.201	31
14.71	6.020	11
			15.91	5.569	27
19.03	4.662	15
			20.11	4.414	31
21.05	4.219	31
			21.53	4.126	36
21.83	4.070	47
			22.65	3.925	75
23.65	3.761	51
			24.90	3.575	34
25.92	3.436	96
			26.89	3.315	34
27.65	3.225	39
			28.54	3.127	30
31.49	2.839	7
			32.19	2.779	7
33.28	2.691	12
			34.23	2.618	7

Embodiment 3

With 9.3gLiOHH ₂O is dissolved in 945.9gH ₂Among the O, add 29.7g pseudo-boehmite and 137.7g silica-gel powder (SiO while stirring ₂, wt%=87.2%), add the 120.0g hexamethylene imine again and be mixed into gel, stir.Gained mixture mole consists of aR: bLiOH: cAl ₂O ₃: SiO ₂: dH ₂O=0.6: 0.1: 0.1: 1: 27.Gel was gone in the stainless steel sealed reactor under 150 ℃ and autogenous pressure dynamic crystallization 100 hours.Product is through cooling, filtration, washing and dry, and diffraction data sees Table 7, and the mole that the anhydrous oxide form is represented consists of 0.128R: 0.096Li ₂O: 0.118Al ₂O ₃: SiO ₂Roasting is after 4 hours under 550 ℃ of fluidizing airs with sample, and diffraction data sees Table 8.The mole that the anhydrous oxide form is represented consists of 0.093Li ₂O: 0.116Al ₂O ₃: SiO ₂

Table 7

2θ(°)	d(_)	I/I 0
			6.23	14.183	100
7.05	12.535	96
			7.71	11.463	43
9.42	9.386	39
			12.67	6.985	17
14.17	6.249	8
			14.47	6.120	7
15.56	5.693	13
			18.93	4.687	16
19.91	4.458	32
			21.41	4.149	19
21.63	4.107	24
			22.36	3.975	47
23.40	3.801	14
			24.83	3.585	23
25.87	3.443	62
			26.62	3.348	40
28.12	3.172	15
			28.94	3.084	10
31.38	2.850	4
			32.83	2.727	4
34.41	2.606	7
			37.63	2.390	7

Table 8

2θ(°)	d(_)	I/I 0
			7.11	12.429	100
7.91	11.174	57
			9.93	8.905	58
12.85	6.887	9
			14.29	6.196	29
14.71	6.020	12
			15.96	5.552	17
18.96	4.679	14
			20.20	4.395	31
21.06	4.217	31
			21.65	4.104	23
21.83	4.070	47
			22.63	3.928	64
23.63	3.764	43
			24.93	3.571	33
25.94	3.434	83
			26.87	3.317	32
27.62	3.229	31
			28.46	3.135	25
31.51	2.838	7
			32.19	2.780	7
33.28	2.691	10
			34.21	2.620	6

Embodiment 4

With 16.8gLiOHH ₂O is dissolved in 187.5gH ₂Among the O, add 37.1g pseudo-boehmite and 462.0g silicon sol while stirring, add the 100g hexamethylene imine again and be mixed into gel, stir.Gained mixture mole consists of aR: bLiOH: cAl ₂O ₃: SiO ₂: dH ₂O=0.5: 0.18: 0.125: 1: 15.Gel was gone in the stainless steel sealed reactor under 150 ℃ and autogenous pressure dynamic crystallization 100 hours.Product is through cooling, filtration, washing and dry, and diffraction data sees Table 9, and the mole that the anhydrous oxide form is represented consists of 0.138R: 0.128Li ₂O: 0.138Al ₂O ₃: SiO ₂Roasting is after 4 hours under 550 ℃ of fluidizing airs with sample, and diffraction data sees Table 10, and the mole that the anhydrous oxide form is represented consists of 0.127Li ₂O: 0.130Al ₂O ₃: SiO ₂

Table 9

2θ(°)	d(_)	I/I 0
			6.34	13.937	100
7.10	12.447	68
			7.78	11.360	39
9.47	9.336	27
			12.74	6.946	14
14.19	6.240	8
			14.50	6.107	5
15.57	5.690	6
			18.68	4.749	17
19.71	4.503	35
			21.45	4.141	17
21.68	4.098	22
			22.48	3.954	43
23.52	3.781	14
			24.83	3.585	23
25.90	3.439	65
			26.75	3.332	31
27.95	3.191	12
			29.01	3.077	10
31.39	2.849	4
			32.91	2.721	3
34.76	2.580	8
			37.72	2.384	5

Table 10

2θ(°)	d(_)	I/I 0
			7.12	12.412	100
7.92	11.160	68
			10.02	8.825	61
12.88	6.871	13
			14.32	6.183	35
14.72	6.016	10
			15.95	5.555	17
18.99	4.672	8
			20.20	4.395	13
21.16	4.198	8
			21.65	4.104	12
21.88	4.061	25
			22.75	3.908	38
23.72	3.750	23
			24.97	3.565	17
25.99	3.427	65
			26.98	3.304	17
27.75	3.214	13
			28.59	3.121	12
31.39	2.849	3
			32.23	2.777	5
33.38	2.684	9
			34.26	2.617	3

Embodiment 5

With 18.6gLiOHH ₂O is dissolved in 1056.8gH ₂Among the O, add 19.8g pseudo-boehmite and 137.7g silica-gel powder while stirring, add 40g HMI again and be mixed into gel, stir.Gained mixture mole consists of aR: bLiOH: cAl ₂O ₃: SiO ₂: dH ₂O=0.2: 0.2: 0.0667: 1: 30.Gel was gone in the stainless steel sealed reactor under 150 ℃ and autogenous pressure dynamic crystallization 100 hours.Product is through cooling, filtration, washing and dry, and diffraction data sees Table 11, and the mole that the anhydrous oxide form is represented consists of 0.114R: 0.063Li ₂O: 0.071Al ₂O ₃: SiO ₂Roasting is after 4 hours under 550 ℃ of fluidizing airs with sample, and diffraction data sees Table 12.The mole that the anhydrous oxide form is represented consists of 0.059Li ₂O: 0.073Al ₂O ₃: SiO ₂

Table 11

2θ(°)	d(_)	I/I 0
			6.28	14.070	100
7.10	12.447	63
			7.76	11.390	62
9.47	9.336	11
			12.74	6.946	33
14.30	6.192	12
			14.54	6.090	16
15.66	5.657	5
			19.03	4.662	16
19.76	4.492	9
			21.51	4.130	17
21.75	4.085	23
			22.43	3.963	36
23.52	3.781	21
			24.88	3.578	16
25.92	3.436	61
			26.70	3.338	19
28.29	3.154	17
			29.07	3.071	14
31.53	2.837	3
			33.01	2.713	4
34.83	2.575	8
			37.70	2.385	3

Table 12

2θ(°)	d(_)	I/I 0
			7.14	12.377	100
7.97	11.090	71
			9.95	8.887	65
12.86	6.882	9
			14.30	6.192	35
14.69	6.029	18
			15.94	5.558	16
19.01	4.667	5
			20.21	4.393	17
21.10	4.209	9
			21.53	4.126	19
21.88	4.061	21
			22.68	3.920	38
23.60	3.769	25
			24.87	3.579	15
25.97	3.430	73
			26.97	3.305	17
27.73	3.216	15
			28.49	3.132	13
31.41	2.847	4
			32.19	2.780	7
33.27	2.692	9
			34.16	2.624	3

Embodiment 6

With 28.0gLiOHH ₂O is dissolved in 731.9gH ₂Among the O, add 21.8g aluminium hydroxide (Shandong Aluminum Plant, industrial goods, Al while stirring ₂O ₃: 46.7wt%), add the 100g hexamethylene imine again and be mixed into gel, stir with the 462.0g silicon sol.Gained mixture mole consists of aR: bLiOH: cAl ₂O ₃: SiO ₂: dH ₂O=0.5: 0.3: 0.05: 1: 30.Gel was gone in the stainless steel sealed reactor under 170 ℃ and autogenous pressure dynamic crystallization 80 hours.Product sees Table 13 through cooling, filtration, washing and dry diffraction data, and the mole that the anhydrous oxide form is represented consists of 0.106R: 0.047Li ₂O: 0.054Al ₂O ₃: SiO ₂Roasting is after 4 hours under 550 ℃ of fluidizing airs with sample, and diffraction data sees Table 14, and the mole that the anhydrous oxide form is represented consists of 0.043Li ₂O: 0.053Al ₂O ₃: SiO ₂

Table 13

2θ(°)	d(_)	I/I 0
			6.23	14.183	80
7.06	12.517	100
			7.73	11.434	43
9.38	9.426	31
			12.69	6.974	13
14.27	6.205	6
			14.54	6.090	17
15.57	5.690	9
			18.96	4.679	10
19.84	4.474	31
			21.48	4.136	19
21.70	4.094	21
			22.40	3.968	39
23.27	3.821	12
			24.87	3.579	25
25.87	3.443	69
			26.60	3.350	38
28.10	3.175	13
			28.94	3.084	11
31.43	2.845	3
			32.96	2.717	5
34.60	2.592	8
			37.68	2.387	7

Table 14

2θ(°)	d(_)	I/I 0
			7.13	12.395	100
7.94	11.132	62
			9.98	8.860	65
12.84	6.893	9
			14.29	6.196	37
14.70	6.024	11
			15.93	5.562	15
18.97	4.677	4
			20.18	4.399	17
21.08	4.213	8
			21.58	4.117	18
21.88	4.061	22
			22.79	3.901	39
23.65	3.761	20
			24.96	3.566	17
25.98	3.429	69
			27.00	3.301	17
27.65	3.225	15
			28.53	3.128	13
31.49	2.840	3
			32.21	2.778	4
33.29	2.691	9
			34.18	2.623	3

Embodiment 7

Present embodiment illustrates the effect of MWW structure Si-Al molecular sieve provided by the invention in benzene and ethylene alkylation.

Will embodiment the sample of 2 preparations press molecular sieve through conventional ammonium salt exchange back: the part by weight of aluminum oxide=3: 7 mixes molecular sieve with aluminum oxide, be shaped to strip catalyst, obtain catalyst sample through 550 ℃ of roastings after 4 hours, with catalyst breakage is 16～20 purpose particles, carries out the alkylation performance evaluation.Catalyzed reaction result is as shown in Table 15.

Benzene and ethylene alkylation evaluation are carried out on the pressurization micro-reactor.The condition of estimating is: 250 ℃ of temperature of reaction, pressure 4.0MPa, benzene liquid air speed 3h ^-1, benzene/ethylene molecule is than 12.

Comparative Examples 2～4

MCM-22, MCM-49 and MCM-56 molecular sieve are prepared the comparative catalyst according to the process of embodiment 7, the comparative catalyst is broken for 16～20 purpose particles, carry out the alkylation performance evaluation, condition is with embodiment 7.Catalyzed reaction result is as shown in Table 15.

Table 15

	Embodiment 7	Comparative Examples 2	Comparative Examples 3	Comparative Examples 4
					Used molecular sieve	The molecular sieve of embodiment 2 preparations	MCM-22	MCM-49	MCM-56
Product/weight % conversion of ethylene ethylbenzene selectivity diethylbenzene selectivity triethyl-benzene selectivity styroyl selectivity	100 96.77 3.01 0.05 99.82	100 95.28 4.01 0.13 99.41	100 96.05 3.39 0.09 99.53	100 95.08 4.13 0.14 99.35

Data as can be seen from table 15, the catalyzer of the specimen preparation of embodiment 2 is in benzene and the reaction of ethene synthesizing ethyl benzene, active suitable with other MWW structure molecular screen, ethylbenzene selectivity and ethylization selectivity all are higher than other MWW structure molecular screen, illustrate that with this MWW structure Si-Al molecular sieve provided by the invention has good alkylated reaction catalytic performance.

Claims (8)

1. a MWW structure Si-Al molecular sieve is characterized in that the mole that this molecular screen primary powder is represented with the anhydrous oxide form consists of xR: yLi ₂O: zAl ₂O ₃: SiO ₂, XRD spectra contains the diffraction peak data of table 1 at least, and the mole of representing with the anhydrous oxide form after the roasting consists of yLi ₂O: zAl ₂O ₃: SiO ₂XRD spectra contains the diffraction peak data of table 2 at least, wherein, R is the template hexamethylene imine, x=0.01～0.5, y=0.0001～0.5, z=0.03～0.5, in table 1 and the table 2, W, M, S and VS represent the relative intensity of diffraction peak, W=0～20, M=20～40, S=40～60, VS=60～100.

Table 1 2θ(°) d(_) I/I ₀ 6.20-6.34 14.25-13.94 VS 7.02-7.16 12.59-12.34 S-VS 7.69-7.83 11.49-11.29 M-S 9.33-9.53 9.48-9.28 M 12.64-12.75 7.00-6.94 W-M 14.17-14.33 6.25-6.18 W 14.47-14.62 6.12-6.06 W 15.54-15.66 5.70-5.66 W 18.68-19.08 4.75-4.65 W 19.68-20.04 4.51-4.43 M 21.41-21.52 4.15-4.13 W-M 21.63-21.78 4.11-4.08 W-M 22.27-22.50 3.99-3.95 W-M 23.27-23.53 3.82-3.78 W 24.79-24.93 3.59-3.57 M 25.82-25.97 3.45-3.43 S-VS 26.60-26.76 3.35-3.33 M 27.95-28.32 3.19-3.15 W 28.89-29.08 3.09-3.07 W 31.27-31.53 2.86-2.84 W 32.80-33.04 2.73-2.71 W 34.35-34.90 2.61-2.57 W 37.46-37.79 2.40-2.38 W

Table 2 2θ(°) d(_) I/I ₀ 7.09-7.17 12.46-12.33 VS 7.91-7.99 11.17-11.06 VS 9.93-10.03 8.90-8.82 VS 12.79-12.90 6.92-6.86 W 14.28-14.35 6.20-6.17 M 14.69-14.74 6.03-6.01 W 15.91-15.96 5.57-5.55 W-M 18.96-19.04 4.68-4.66 W 20.08-20.27 4.42-4.38 M 21.05-21.16 4.22-4.20 M 21.51-21.65 4.13-4.10 M 21.78-21.89 4.08-4.06 M-S 22.62-22.79 3.93-3.90 VS 23.59-23.72 3.77-3.75 M-S 24.86-25.01 3.58-3.56 W-M 25.89-26.05 3.44-3.42 VS 26.85-27.01 3.32-3.30 M 27.61-27.78 3.23-3.21 M 28.42-28.60 3.14-3.12 W-M 31.38-31.61 2.85-2.83 W 32.07-32.31 2.79-2.77 W 33.17-33.43 2.70-2.68 W 34.08-34.35 2.63-2.61 W

2. according to the molecular sieve of claim 1, it is characterized in that x=0.05～0.4, y=0.001～0.4, z=0.04～0.4.

3. according to the molecular sieve of claim 2, it is characterized in that x=0.08～0.2, y=0.03～0.2, z=0.05～0.3.

4. the preparation method of the MWW structure Si-Al molecular sieve of claim 1 is characterized in that silicon source, aluminium source, lithium hydroxide, hexamethylene imine and deionized water are mixed into glue, and its mole consists of aR: bLiOH: cAl ₂O ₃: SiO ₂: dH ₂O, crystallization 2～200 hours and reclaim product under 120～220 ℃ and autogenous pressure then, wherein, R is a hexamethylene imine, a=0.05～1.0, b=0.01～0.5, c=0.03～0.5, d=2～100.

5. according to the method for claim 4, wherein the silicon source is selected from solid silicone, silicic acid or silicon sol, and the aluminium source is selected from aluminum oxide, aluminium hydroxide or hydrated aluminum oxide.

6. according to the method for claim 5, wherein said hydrated aluminum oxide is a pseudo-boehmite.

7. according to the method for claim 4, wherein a=0.1～0.8, b=0.05～0.4, c=0.04～0.4, d=5～80.

8. according to the method for claim 6, wherein a=0.2～0.6, b=0.1～0.3, c=0.05～0.3, d=10～40.