CN101265100A - Method for preparing macropore-mesopore Ce1-xZrxO2 solid solution - Google Patents

Abstract

The invention relates to a method for producing macroporous-mesoporous Ce1-xZrxO2 solid solution, which belongs to the technology fieldof multiphase catalysis. Currently, the synthetic Ce1-xZrxO2 solid solution has mesoporous structure only. Report on the production of Ce1-xZrxO2 solid solution with three-dimensional ordered macroporous-worm-like mesoporous structure is not available in domestic and abroad. The method comprises the following steps: preparing an ethanol solution of cerium chloride and zirconium oxychloride as metal sources and triblock polymers as soft template under room temperature; impregnating a polymethyl methacrylate monodisperse microsphere template with the solution; suction-filtering under vacuum; drying in room temperature air with a relative humidity below 40%; and burning to obtain the Ce1-xZrxO2 solid solution with three-dimensional ordered macroporous-worm-like mesoporous structure. The inventive Ce1-xZrxO2 solid solution is helpful for diffusion and has large specific surface area, and has good application prospect.

Description

The foramen magnum-mesoporous Ce of a kind of preparation 1-xZr xO 2The method of sosoloid

Technical field

The invention belongs to heterogeneous catalysis field, be specifically related to a kind of foramen magnum-mesoporous Ce _1-xZr _xO ₂The preparation method of sosoloid relates in particular to the poroid meso-pore Ce of three-dimensional ordered macroporous-worm of utilizing dual mould plate agent to prepare _1-xZr _xO ₂The method of sosoloid.

Background technology

Ce _1-xZr _xO ₂Sosoloid has good thermostability, storage oxygen release performance and low-temperature catalyzed performance, has become the important component in the motor-vehicle tail-gas three-way catalyst.Studies show that the cerium zirconium sosoloid of high-specific surface area helps to improve its storage oxygen release ability, thereby improves three-effect catalysis efficient.Having three-dimensional ordered macroporous structure and macropore hole wall is the Ce of meso-hole structure _1-xZr _xO ₂Sosoloid is because its favourable mass transfer feature and bigger specific surface area have important use value in heterogeneous catalysis field.With triblock copolymer EO ₂₀PO ₇₀EO ₂₀And EO ₁₀₆PO ₇₀EO ₁₀₆, cetyl trimethylammonium bromide, polyoxyethylene glycol-4000 or H (CH ₂CH ₂CH ₂(CH) CH ₂CH ₃) ₈₉(OCH ₂CH ₂) ₇₉But OH is the template synthetic aperture is the poroid meso-pore Ce of order mesoporous or worm of 4～10nm _1-xZr _xO ₂Sosoloid (C.Ho, et al., J Mater Chem, 2005,15:2193; Y.Gu, et al., J Rare Earths, 2007,25:710; Q.Yuan, etal., J Am Chem Soc, 2007,129:6698; E.L.Crepaldi, et al., Angew ChemInt Ed, 2003,42:347; T.Brezesinski, et al., New J Chem, 2005,29:237), but up to now, about the Ce of three-dimensional ordered macroporous-poroid meso-hole structure of worm _1-xZr _xO ₂The technology of preparing of sosoloid does not still have report in document and the patent at home and abroad.

Summary of the invention

The object of the present invention is to provide a kind of three-dimensional ordered macroporous-Ce of the poroid meso-hole structure of worm _{1- x}Zr _xO ₂The preparation method of sosoloid.The target product that the present invention makes be single-phase cubic polycrystalline three-dimensional ordered macroporous-the poroid meso-pore Ce of worm _1-xZr _xO ₂Sosoloid.

The present invention is a hard template with orderly closely packed polymethylmethacrylate mono-dispersion microballoon, with EO ₂₀PO ₇₀EO ₂₀Or EO ₁₀₆PO ₇₀EO ₁₀₆Being soft template, is source metal with Cerium II Chloride and basic zirconium chloride, adopts solvent evaporates self-organization method to prepare the Ce of the three-dimensional ordered macroporous structure with the poroid mesoporous wall of worm _{1- x}Zr _xO ₂Sosoloid, concrete steps are as follows:

1) under normal temperature, normal pressure, magnetic agitation condition, with soft template EO ₁₀₆PO ₇₀EO ₁₀₆Or EO ₂₀PO ₇₀EO ₂₀Be dissolved in mass concentration and be in 0%～100% the ethanolic soln;

2) with CeCl ₃7H ₂O and ZrOCl ₂8H ₂O is 6/4 or 7/3 to add in the system that step 1) obtains by the Ce/Zr mol ratio;

3) with step 2) institute join the solution impregnation hard template, hard template is orderly closely packed polymethylmethacrylate mono-dispersion microballoon;

4) after suction filtration is removed surplus solution, be lower than dry 48h under 40% relative humidity and the air at room temperature, rise to 300 ℃ of calcination 3h with the speed of 1 ℃/min from room temperature again after, be warming up to 500 ℃ of calcination 5h from 300 ℃ again, obtain faint yellow foramen magnum-mesoporous Ce _1-xZr _xO ₂Sosoloid.

Wherein, described foramen magnum-mesoporous Ce _1-xZr _xO ₂Sosoloid is Ce _0.6Zr _0.4O ₂Sosoloid or Ce _0.7Zr _0.3O ₂Sosoloid; Preparation Ce _0.6Zr _0.4O ₂The mass ratio of the used all ingredients of sosoloid is: soft template: ethanolic soln: CeCl ₃7H ₂O: ZrOCl ₂8H ₂O: hard template=1: 15: 2.235: 1.289: 5, preparation Ce _0.7Zr _0.3O ₂The mass ratio of the used all ingredients of sosoloid is: soft template: ethanolic soln: CeCl ₃7H ₂O: ZrOCl ₂8H ₂O: hard template=1: 15: 2.608: 0.967: 5.

With the faint yellow Ce of gained _1-xZr _xO ₂Solid-solution powder product N ₂Adsorption-desorption, X-ray diffractometer (XRD), transmission electron microscope (TEM) and selected area electron diffraction technology such as (SAED) characterize.The result shows that adopting the obtained sample of present method is single-phase polycrystalline Ce _1-xZr _xO ₂Sosoloid is three-dimensional ordered macroporous-the poroid mesoporous material of worm.

The present invention has following beneficial effect:

Three-dimensional ordered macroporous-meso-pore Ce that the inventive method is prepared _1-xZr _xO ₂X=0.3 or 0.4 in the sosoloid has best storage oxygen release performance, and because its favourable mass transfer feature and bigger specific surface area have important use value in heterogeneous catalysis field.

Description of drawings

Fig. 1, Ce _1-xZr _xO ₂The wide-angle XRD spectra of sosoloid sample, wherein, a, b, c, d are respectively the wide-angle XRD spectra of the sample of embodiment 1,2,3 and 4 preparations.

Fig. 2, Ce _1-xZr _xO ₂The little angle XRD spectra of sosoloid sample, wherein, a, b, c, d are respectively the little angle XRD spectra of the prepared sample of embodiment 1,2,3 and 4.

Fig. 3, Ce _1-xZr _xO ₂The TEM photo of sosoloid sample, wherein, a, e, f are the Ce of the preparation of embodiment 1 _1-xZr _xO ₂The TEM photo of sosoloid sample, the illustration among Fig. 3 f are the SAED pattern; B, c, d are respectively the Ce of embodiment 2,3,4 preparations _1-xZr _xO ₂The TEM photo of sosoloid sample.

The Ce of Fig. 4, embodiment 1 preparation _1-xZr _xO ₂The N of sosoloid sample ₂The adsorption-desorption thermoisopleth, wherein, illustration is the pore size distribution curve of this sample.

Wherein, θ represents diffraction angle among Fig. 1 and 2; P and p among Fig. 4 ₀Expression air pressure and saturated pressure, V and D represent adsorption volume and aperture, d is an operator.

The invention will be further described below in conjunction with the drawings and specific embodiments.

Embodiment

Embodiment 1

Under normal temperature, condition of normal pressure, with 1g EO ₂₀PO ₇₀EO ₂₀Being dissolved in the 15g dehydrated alcohol is in 100% aqueous ethanolic solution; The dissolving back adds 6mmol CeCl fully ₃7H ₂O and 4mmol ZrOCl ₂8H ₂O continues to stir 1h; Place the 5g hard template in B, drip until soaking into fully with the solution of preparation, suction filtration is removed unnecessary liquid, and relative humidity is lower than 40% air at room temperature and places 48h down; Respectively behind calcination 3h and the 5h, promptly obtain the poroid meso-pore Ce of three-dimensional ordered macroporous-worm in 300 ℃ and 500 ℃ with the temperature rise rate of 1 ℃/min _0.6Zr _0.4O ₂Sosoloid.

The specific surface area of sosoloid is 64m ²/ g, pore volume are 0.23m ³/ g; Wherein the big pore specific surface area of aperture in 36～200nm is 14m ²/ g, pore volume are 0.13m ³/ g; And the mesoporous specific surface area of aperture in 2～36nm is 50m ²/ g, pore volume are 0.10m ³/ g.

Embodiment 2

Under normal temperature, normal pressure, with 1g EO ₂₀PO ₇₀EO ₂₀Be dissolved in the aqueous ethanolic solution of 15g 60%, the dissolving back adds 6mmol CeCl fully ₃7H ₂O and 4mmol ZrOCl ₂8H ₂O continues to stir 1h; Place the 5g hard template in B, drip until soaking into fully with the solution of preparation, suction filtration is removed unnecessary liquid, and relative humidity is lower than 40% air at room temperature and places 48h down; Respectively behind calcination 3h and the 5h, promptly obtain the poroid meso-pore Ce of three-dimensional ordered macroporous-worm in 300 ℃ and 500 ℃ with the temperature rise rate of 1 ℃/min _0.6Zr _0.4O ₂Sosoloid.

Embodiment 3

Under normal temperature, condition of normal pressure, with 1g EO ₂₀PO ₇₀EO ₂₀Be dissolved in the 15g water (i.e. 0% aqueous ethanolic solution), the dissolving back adds 7mmol CeCl fully ₃7H ₂O and 3mmol ZrOCl ₂8H ₂O continues to stir 1h; Place the 5g hard template in B, drip until soaking into fully with the solution of preparation, suction filtration is removed unnecessary liquid, and relative humidity is lower than 40% air at room temperature and places 48h down; Respectively behind calcination 3h and the 5h, promptly obtain the poroid meso-pore Ce of three-dimensional ordered macroporous-worm in 300 ℃ and 500 ℃ with the temperature rise rate of 1 ℃/min _0.7Zr _0.3O ₂Sosoloid.

Embodiment 4

Under normal temperature, condition of normal pressure, with 1g EO ₁₀₆PO ₇₀EO ₁₀₆Be dissolved in 15g 95% aqueous ethanolic solution, the dissolving back adds 7mmol CeCl fully ₃7H ₂O and 3mmol ZrOCl ₂8H ₂O continues to stir 1h; Place the 5g hard template in B, drip until soaking into fully with the solution of preparation, suction filtration is removed unnecessary liquid, and relative humidity is lower than 40% air at room temperature and places 48h down; Respectively behind calcination 3h and the 5h, promptly obtain the poroid meso-pore Ce of three-dimensional ordered macroporous-worm in 300 ℃ and 500 ℃ with the temperature rise rate of 1 ℃/min _0.7Zr _0.3O ₂Sosoloid.

Claims (2)

1, the foramen magnum-mesoporous Ce of a kind of preparation _1-xZr _xO ₂The method of sosoloid is characterized in that, may further comprise the steps:

1) under normal temperature, normal pressure, magnetic agitation condition, with soft template EO ₁₀₆PO ₇₀EO ₁₀₆Or EO ₂₀PO ₇₀EO ₂₀Be dissolved in mass concentration and be in 0%～100% the ethanolic soln;

2) with CeCl ₃7H ₂O and ZrOCl ₂8H ₂O is 6/4 or 7/3 to add in the system that step 1) obtains by the Ce/Zr mol ratio;

3) with step 2) institute join the solution impregnation hard template, hard template is orderly closely packed polymethylmethacrylate mono-dispersion microballoon;

4) after suction filtration is removed remaining liq, solid is being lower than dry 48h under 40% relative humidity and the air at room temperature, after rising to 300 ℃ of calcination 3h with the speed of 1 ℃/min from room temperature again, be warming up to 500 ℃ and calcination 5h from 300 ℃ of speed again, obtain faint yellow foramen magnum-mesoporous Ce with 1 ℃/min _1-xZr _xO ₂Sosoloid;

Wherein, soft template, ethanolic soln, CeCl ₃7H ₂O, ZrOCl ₂8H ₂The mass ratio of O and hard template is 1: 15: 2.235: 1.2 89: 5 or 1: 15: 2.608: 0.967: 5.

2, follow according to the described method of claim 1, it is characterized in that, described foramen magnum-mesoporous Ce _1-xZr _xO ₂Sosoloid is Ce _0.6Zr _0.4O ₂Sosoloid or Ce _0.7Zr _0.3O ₂Sosoloid.

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