CN100496745C

CN100496745C - Method for preparing line shape or stick shape polycrystalline Ce06Zr03Y01O2 solid solution

Info

Publication number: CN100496745C
Application number: CNB2007101189542A
Authority: CN
Inventors: 戴洪兴; 张玉娟; 邓积光; 何洪; 訾学红
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2007-06-15
Filing date: 2007-06-15
Publication date: 2009-06-10
Anticipated expiration: 2027-06-15
Also published as: CN101125302A

Abstract

The invention relates to a preparing method for the linear or clubbed multi crystal Ce0.6Zr0.3Y0.1O2 sosoloid. The traditional method is hard to make the linear or clubbed multi crystal Ce0.6Zr0.3Y0.1O2 sosoloid. The invention takes the cetyl trimethylammonium bromide of a lower price as the surface active agent, obtain the Ce0.6Zr0.3Y0.1O2 avant garde via the water heating process, and then obtain the linear or clubbed multi crystal Ce0.6Zr0.3Y0.1O2 sosoloid by burning, wherein, the length of the linear or clubbed body is thirty nanometer to two micron. The invention can obtain cerium zirconium yttrium compound oxide and is the catalyst material in the material domain. The material has a wide applying potential in the multi catalyze, the storing and releasing of the oxygen, the solid fuel battery, the optical material, the solid electrolyte, the solid sensor and the high temperature heat proof refrigeration material.

Description

Wire or rod-like polycrystal Ce 0.6Zr 0.3Y 0.1O 2The solid solution preparation method

Technical field

The present invention relates to a kind of wire or rod-like polycrystal Ce _0.6Zr _0.3Y _0.1O ₂The solid solution preparation method relates in particular to and utilizes hydrothermal synthesis method to prepare polycrystalline Ce _0.6Zr _0.3Y _0.1O ₂The method of solid solution.

Background technology

In more than ten years in the past, cerium base oxide and cerium zirconium sosoloid are particularly noticeable because of the ability with storage oxygen release, and these materials can be applicable to catalytic field, and particularly motor vehicle vent gas purification catalysis agent is to reduce its pollution to atmosphere.Cerium zirconium sosoloid had obtained more environmentalists' favor in recent years, and its application is also constantly enlarging.

The conventional method of preparation cerium zirconium sosoloid has sol-gal process, homogeneous precipitation method, template synthetic method etc., but adopt the prepared cerium zirconium sosoloid less stable of these methods, often, cause its specific area significantly to descend, thereby influence its performance widely because of high temperature sintering changes brilliant phenomenon.At present more for the research of cerium zirconium sosoloid, but very few for the report of cerium zirconium yttrium solid solution.In our previous work, adopt the prepared Ce of coprecipitation _0.6Zr _0.4-xY _xO ₂(x=0.05,0.1) is though the specific area of solid solution can reach 198m ²/ g, but its pattern is the three-dimensional manometer particle, and this preparation method fails to obtain having the polycrystalline Ce of specific morphology _0.6Zr _0.4-xY _xO ₂Solid solution.And,, can obtain the polycrystalline cerium zirconium yttrium solid solution of nano wire (nanometer rods) shape by control hydrothermal temperature and hydro-thermal time according to the method that the present invention describes.

La etc. (La R J, et al.Mater Sci Eng:A, 2004,368:145) porous anodic aluminium oxide (AAO) with costliness is a hard template, has prepared the CeO that diameter and length are respectively cube crystal phase structure of 60nm and 50 μ m ₂Nano wire.Xu etc. (Xu A W, et al.J Am Chem Soc, 2003,125:1494) with Dy ₂O ₃Powder is that presoma is being pressed the Dy (OH) that has obtained the pattern uniqueness in the still behind 160 ℃ of hydro-thermal 48h certainly ₃Nanotube, its external diameter are 40～500nm, and internal diameter is 20～300nm, and length is 1～4 μ m.(Wang X such as Wang, et al.Angew Chem Int Ed, 2002,41 (24): 4790) method that adopts hydrothermal crystallizing (180 ℃ of constant temperature 12h) and control the pH value of solution value has been synthesized multiple rare-earth hydroxide nano wire, its diameter is 20～30nm, the longest 5 μ m that reach of length.Yada etc. are that soft template, urea are that the sluggish precipitation of precipitating reagent synthesizes rare-earth oxide nano (Yada M by molecule self assembly mode with the lauryl sodium sulfate, et al.AdvMater, 2002,14 (4): 309), and proposition need not to utilize novel synthesis (Yada M, et al.Adv Mater, 2004 of template agent, 16 (16): 1448), promptly add inorganic matter Na ₂SO ₄, NaH ₂PO ₄Deng, enter the reactant mixed system by the coexisting ion self assembly, and then form oxide hollow Nano pipe.

In recent years, about wire CeO ₂Report more, also roll up around the research work of cerium zirconium, but be difficult to solve cerium zirconium high temperature sintering, influenced this problem of its catalytic performance.The present invention plants the storage oxygen performance that can increase the cerium zirconium to the doping of yttrium to a certain extent, and owing to make the cerium zirconium have good structure and texture, this has increased its high-temperature aging resisting performance to a certain extent, makes storage oxygen performance and reducing property drop to minimum.

Summary of the invention

The object of the present invention is to provide the preparation method of the cerium zirconium yttrium solid-solution particles of a kind of wire or bar-shaped pattern, the doping of yttrium improves hydrogen-storing material ground storage oxygen release performance effectively, improves the catalytic performance of catalyst.Cerium zirconium yttrium is suitable as carrier as a kind of composite oxides of high storage oxygen and is applied in catalytic field, improves the decentralization of noble metal catalyst, promotes the noble metal availability, reduces noble metal dosage, thereby reduces the Preparation of Catalyst cost.

Under stirring condition, soluble metallic salt with Ce, Zr, Y is a raw material, with softex kw (CTAB) is the template agent, with urea is precipitating reagent, urea is added in the mixed solution that soluble metallic salt and CTAB formed of Ce, Zr, Y, hydrothermal crystallizing 72h under 120～160 ℃ condition, naturally cool to room temperature afterwards, with the product filtration that obtains, deionized water and ethanol washing, dry, grind, promptly get wire or rod-like polycrystal Ce after in air atmosphere, rising to 550 ℃ of calcination 3h with the heating rate of 1 ℃/min _0.6Zr _0.3Y _0.1O ₂Solid-solution powder.

With gained powdered product D8 ADVANCE type X-ray diffractometer (XRD), employing ZEISS SUPRA 55 type high resolution scanning electron microscopes (HRSEM), JEOL-2010 type transmission electron microscope (TEM) and SEAD technology such as (SAED) carry out structure and pattern characterizes.The result shows that adopting the obtained sample of this method is wire or rod-like polycrystal Ce _0.6Zr _0.3Y _0.1O ₂Solid solution, the length of its center line or shape are 30nm～2 μ m.

The present invention adopts a kind of comparatively simple method to prepare wire or rod-like polycrystal Ce _0.6Zr _0.3Y _0.1O ₂Solid-solution particles.This method preparation cost is low, and operating process is easy, and target product has oxygen and stores and release, be suitable as catalyst and carrier, significant to improving the anti-poisoning capability of noble metal, can reduce element sulphur to the poisoning of noble metal, improve the service life of catalyst.Therefore in combustion of natural gas as catalyst, purify air, reduce the discharge of harmful gases aspect and have very big application potential.

Description of drawings

In order further to understand the present invention, elaborate with embodiment below, and provide accompanying drawing and describe the present invention and obtain wire or bar-shaped cerium zirconium yttrium solid-solution particles, wherein:

Fig. 1 is Ce _0.6Zr _0.3Y _0.1O ₂The XRD spectra of solid solution sample.Curve (a) Ce wherein _0.6Zr _0.3Y _0.1O ₂Solid solution embodiment 1; Curve (b) Ce _0.6Zr _0.3Y _0.1O ₂Solid solution embodiment 2.

Fig. 2 (a), 2 (b) are respectively Ce _0.6Zr _0.3Y _0.1O ₂The high resolution scanning photo (HRSEM) of solid solution embodiment 1 sample, Fig. 2 (c) is Ce _0.6Zr _0.3Y _0.1O ₂The transmission electron microscope photo (TEM) of solid solution embodiment 1 sample, wherein the illustration among Fig. 2 (c) is the selected area electron diffraction figure (SAED) of this sample.

Fig. 3 (a), 3 (b) are respectively Ce _0.6Zr _0.3Y _0.1O ₂The HRSEM photo of solid solution embodiment 2 samples, Fig. 3 (c) is Ce _0.6Zr _0.3Y _0.1O ₂The TEM photo of solid solution embodiment 2 samples, wherein the illustration among Fig. 3 (c) is the SAED pattern of this sample.。

The specific embodiment

Embodiment 1: under normal temperature, normal pressure and magnetic agitation condition, 7.278g CTAB is dissolved in the 75ml deionized water stirring and dissolving; With 0.006mol Ce (NO ₃) ₃6H ₂O, 0.003mol ZrO (NO ₃) ₂2H ₂O, 0.001molY (NO ₃) ₃6H ₂O, be dissolved in the 5ml deionized water, stirring and dissolving, contain cerium more than inciting somebody to action, zirconium, the mixed liquor of yttrium joins in the solution of CTAB, and then in this solution, add 0.2mol urea, after continuing to stir 2h, above-mentioned solution is transferred to (60% volume loading) in the stainless steel cauldron that liner is a polytetrafluoroethylene (PTFE), put into again in the insulating box in 120 ℃ of insulation 72h, naturally cool to room temperature afterwards, the product that obtains is filtered, deionization and ethanol wash respectively, dry, obtain the target product presoma after grinding evenly, again this presoma is placed Muffle furnace after air atmosphere rises to 550 ℃ of calcination 3h with the heating rate of 1 ℃/min, promptly to get wire or rod-like polycrystal Ce _0.6Zr _0.3Y _0.1O ₂Solid solution, length are 30nm～2 μ m.

Embodiment 2: obtain solution according to embodiment 1, it is transferred in the stainless steel cauldron that liner is a polytetrafluoroethylene (PTFE), put into again in the insulating box in 160 ℃ of insulation 72h, naturally cool to room temperature afterwards, with the product filtration, deionization and the ethanol that obtain wash respectively, dry, obtain the target product presoma after grinding evenly, again this presoma is placed Muffle furnace after air atmosphere rises to 550 ℃ of calcination 3h with the heating rate of 1 ℃/min, promptly to get wire or rod-like polycrystal Ce _0.6Zr _0.3Y _0.1O ₂Solid solution, length are 30nm～2 μ m.

Claims

1. wire or rod-like polycrystal Ce _0.6Zr _0.3Y _0.1O ₂The preparation method of solid solution is characterized in that, may further comprise the steps:

Under stirring condition, with the softex kw is surfactant, the soluble metallic salt of Ce, Zr and Y is a raw material, is precipitating reagent with urea, and wherein Ce in the soluble metallic salt of softex kw, Ce and urea amount of substance are than being 2:0.6:20; Urea is added in the mixed solution that the soluble metallic salt of softex kw and Ce, Zr and Y forms, after continuing to stir, said mixture is transferred in the stainless steel autoclave that liner is a polytetrafluoroethylene (PTFE), carry out thermostatted water heat treatment 72.h in 120～160 ℃ again, naturally cool to room temperature afterwards, with the product filtration, deionized water and the ethanol that obtain wash respectively, dry, grind, promptly obtain wire or rod-like polycrystal Ce after in air atmosphere, rising to 550 ℃ of calcination 3h with the heating rate of 1 ℃/min _0.6Zr _0.3Y _0.1O ₂Solid-solution powder.

2. preparation method according to claim 1 is characterized in that, the soluble metallic salt of described cerium is a nitrate; The soluble metal zirconates of described zirconium is the nitric acid oxonium salt; The soluble metallic salt of described yttrium is a nitrate.