CN101698149B - Supported gold-PGM alloy catalyst with stable storage property and preparation method thereof - Google Patents

Abstract

The invention relates to a supported gold-PGM alloy catalyst with stable storage property and a preparation method thereof. An active component is Au, an accessory ingredient is Pd or Pt in PGM, and a carrier is a Al2O3 composite oxide modified by Al2O3 or MIOx and MIIOx, wherein the atomic ratio of Au to PGM is 1.0:1.0-1.0:1.0*10-2; the atomic ratio of Au to MI+MII is 1.0:1.0-1.0:10; the atomic ratio of MI to MII is 2.0:1.0-0.2:1.0; the atomic ratio of Au to Al is 1.0:1.0*103-1:0:10; MI is La; and MII is Fe, Co or Ni. The composite oxide carrier is prepared by an impregnation method or a coprecipitation method. After being supported with MIOx and MIIOx, Al2O3 is roasted at a temperature of between 800 and 1,000 DEG C to generate a spinelle or perovskite structure. The catalyst of the invention catalytically oxidizes micro CO (0.1 percent to 1.5 percent) in the air into CO2 at ambient temperature and in ambient humidity, and has the advantages of stable catalysis property, pressure drop meeting the requirements of a gas mask and a mining self-rescuer and low cost.

Description

Load type gold-PGM alloy catalyst that storge quality is stable and preparation method thereof

(1), technical field

(Platinum Group Metal, PGM) alloy catalyst specifically, tie up under environment temperature, the ambient humidity that trace (0.1%～1.5%) CO becomes CO in the catalytic oxidation air to the present invention relates to a kind of gold-platinum metal ₂, the stable and pressure of catalytic performance falls and satisfies load type gold-platinum metal alloy catalyst breathing mask and air cleaning requirement, that tool industrial applicibility and cost are relatively low and preparation method thereof.

(2), background technology

At present, the breathing mask of China is used the Hopcalite catalyst more, and it is to be composite oxide catalysts (Lamb, A.B., Bray, W.C, Frazer, the J.C.W. of Main Ingredients and Appearance with CuO-MnOx; Ind.Eng.Chem., 1920,12,213), be used breathing mask catalyst material just in the World War I.Its fatal shortcoming is that water-resistance is poor, therefore " oxidation tank " preceding must to add a volumes bigger, " drying chamber " that weight is heavier.Load type gold catalyst can be eliminated CO (An Lidun, Qi Shixue, Zou Xuhua, rope palm bosom under environment temperature (10 ℃～40 ℃) and ambient humidity; Practical low-temperature CO oxidizing catalyst; Chinese invention patent ZL 00 1 22829.3), be applied to breathing mask and can remove the preceding drying chamber of catalyst from.For solving the problems of stability in storage of load type gold catalyst; The applicant's analysis-by-synthesis and The effects advised both at home and abroad and some measure of the stable gold catalyst catalyzing performance tested; Development has also been developed the stable load type gold catalyst (An Lidun of storge quality; Qi Shixue, Zou Xuhua, " load type gold catalyst that catalytic performance is stable and preparation method thereof " Chinese invention patent, ZL200410024509.6 authorize day: 2008/5/28; International monopoly (PCT) publication number WO 2006/007774A1,2006/01/26), the patent technology of preparing (An Lidun that adopts the applicant to research and develop; Qi Shixue, rope palm bosom, Weng Yonggen; Zou Xuhua; " a kind of preparation method of new load type nano gold catalyst ", Chinese invention patent, ZL 03138786.1 are authorized day: 2006/6/14) carrying out the industrialization trial production.

Bayer company before 40 years (Bayer, UK patent 1 246 015,1971; US Patent 3,775 342, and 1973; US Patent 1 521 652,1978; ), Hoechst company (Hoechst, DAS1 296 138; 1967) and Knapsack company (Knapsack, DAS 1 244 766,1965) will be the synthetic (Chen Mingshu that the loading type Pd-Au bimetallic catalyst of active component successfully is used for vinyl acetate with Pd; Goodman D W, Chin.J.Catal., 2008; 29,11,1178-1186).Japan's catalyst Co. is declared with Au-Pb/Al recently ₂O ₃Catalyst is used for the synthetic of Glycolic acid methyl esters, and has set up and produced tens of tons pilot plant (Rodriguez J A, 18th Meeting of the NorthAmerican Catalysis Society, Mexico, 2003) per year.U.S. Nanostellar, Inc. company developing Au-Pd bimetallic cleaning catalyst for tail gases of automobiles (Fujdala, Kyle L./Truex, Timothy J.EP1925362, May 2008; EP1938893, Jul 2008; US20080125313, May 2008; US20080124514, May 2008).In above-mentioned Pd-Au bimetallic catalyst series, main active component remains platinum metal, and Au mainly is the performance promoter effect, and the catalytic performance of platinum metal is carried out modulation.In addition, the Au-Pd catalyst is in the selective oxidation of organic matter liquid phase (Venezia A M, EurapaCatVI, Austria, 2003; Laura Prati Alberto Villa, et al., Journal of Catalysis, Vol.244no.1,113-121,2006; Catalysis Today, Vol.122no.3/4,, 2007; ) H ₂With O ₂The directly synthetic H of reaction ₂O ₂(Gu Zhonghua, Luo Laitao. (27) 719) etc. catalysis journal, 2006,8: demonstrate good catalytic performance in the course of reaction.Hutchings research group continuously Nature (Hughes M D, Hutchings G J, Nature, 2005,437,1132) and Science (Enache D I, HutchingsG J, Science, 2006, delivered Au-Pd/TiO on 311:362) ₂Catalyst is used for the result of study of the liquid phase Selective Oxidation oxygenatedchemicals of hydro carbons and primary alconol, and not only catalytic activity is high, and adopts air oxidation, need not organic solvent.They also try out this catalyst in H ₂O ₂Synthetic (Phys.Chem.Chem.Phys., 2008,10,1921-1930).People such as Corma (Corma A, Serna P, Science, 2006,313:332) with Au-Pd/TiO ₂Catalyst is used for the chemo-selective hydrogenation reaction of nitro compound.Naknam etc. utilize immersion process for preparing to go out the Au-Pt/A-zeolite catalyst, and CO conversion ratio and selectivity under the hydrogen rich gas atmosphere reach good effect.(Suo, Z./Ma, C./Jin, M./He, T./An, L., The active phase of Au-Pd/Al such as fiber crops spring swallow, rope palm bosom, An Lidun ₂O ₃For COoxidation; Catalysis Communications; 9 (13); P.2187-2190; Jul 2008) studied Au-Pd bimetallic Au catalyst, the result shows that the synergy between the bimetallic component helps improving the activity of Catalyst for CO oxidation reaction and hydrodesulfurization reaction, but catalytic activity reduces after generating the Au-Pd alloy.Dong Yingnan etc. (SCI, 30 (7), 1397-1401,2009) thus be disclosed in the electron density around Pd transfer portion electronics increases the Pd atom of Au atom in the synthetic Au-Pd nanosphere (this should be for increasing the absorption O that dissociates on the Pd atom ₂The ability of CO absorption is favourable on molecule and the Au atom).But also do not have so far can be business-like the fixedly composition and preparation technology's appearance of support type Au-PGM catalyst of the CO of being used for low-temperature oxidation reaction.

(3), summary of the invention

Technical problem to be solved by this invention is, seek a kind of environment temperature (10 ℃～50 ℃) and ambient humidity (relative humidity 60%～100%) down high, stable performance, the pressure of catalytic reaction activity fall and satisfy that breathing mask is practical to be required and load type gold-PGM alloy catalyst that storge quality that cost is relatively low is stable and preparation method thereof.

Technical scheme of the present invention is following:

Load type gold-PGM alloy catalyst that a kind of storge quality is stable is characterized in that: active component is Au, and auxiliary agent is Pd or the Pt among the PGM, and carrier is moulding Al ₂O ₃Or the Al of MIOx and MIIOx modification ₂O ₃Composite oxides, the atomic ratio of Au and PGM are 1.0: 1.0～1.0: 1.0 * 10 ^-2, the atomic ratio of Au and MI+MII is 1.0: 1.0～1.0: 10, the atomic ratio of MI and MII is 2.0: 1.0～0.2: 1.0; The atomic ratio of Au and Al is 1.0: 1.0 * 10 ³～1.0: 10; Wherein MI is La, and MII is Fe or Co or Ni, and PGM refers to platinum metal.

Wherein composite oxide carrier is to adopt dipping method or coprecipitation method preparation, Al ₂O ₃Load MIOx is behind the MIIOx, through 800 ℃-1000 ℃ roasting, to generate spinelle or perovskite structure.

Carrier is handled through dry, reduction with the salting liquid of equi-volume impregnating load P GM, becomes " the carrier that load has the PGM metal of dispersion ^M", then, use the deposition-precipitation method or anion infusion process at " carrier ^M" go up the salting liquid of load Au, get finished catalyst through washing, dry, activation processing.

Deposition-the precipitation method or anion infusion process are adopted in the load of Au; Wherein, Deposition-the precipitation method for the oxide carrier with high-specific surface area of moulding in advance after dried; Inserting temperature is in the active component A u precursor solution of 350K, in continuous stirring, dropwise adds aqueous slkali, and control pH value of solution value is 4.5～8.5 under constant temperature; Until deposition fully, get finished catalyst through sedimentation, filtration, washing, drying, activation processing;

Said aqueous slkali is Na ₂CO ₃Or K ₂CO ₃Or the aqueous solution of NaOH or KOH.

" carrier ^M" catalyst precarsor after the load gold salt behind hydrogen reducing, auxiliary agent Pd or Pt and part A u generation Au-PGM alloy.

The present invention adopts Al ₂O ₃Or the Al of composite oxides modification ₂O ₃Carrier; The preparation load type nano gold catalyst; Its substantive distinguishing features is: catalyst surface part gold grain and transition metal form alloy structure; The synergy of adsorb oxygen molecule ability and Au CO absorption ability is left in the strong solution of PGM, thereby has improved the activity of load type nano gold catalyst, and the alloy structure that part A u and PGM generate constitutes anchor pin center (pinningcenters); Play a part to stop the migration of catalyst surface nanogold particle and assemble and grow up, stablized its long-term use and storage process in structure and the stability of catalytic activity.

Compared with present technology, the substantive distinguishing features that also has of the present invention is: 1. have good CO catalytic oxidation under low temperature and become CO ₂Catalytic activity; 2. have the performance that good anti-water vapour is poisoned, activity stabilized under relative humidity≤100% (23 ℃) situation, can save drying chamber before the beds.3. has good anti-long term storage performance.4. bed layer pressure is fallen and is met the practical requirement of breathing mask.5. preparation condition is more gentle than patent ZL 200410024509.6 technology, and can reduce golden consumption to a certain extent, has lower catalyst cost.

(4), the specific embodiment

Further specify the present invention below in conjunction with embodiment.

Activity of such catalysts component of the present invention is a gold, and auxiliary agent is a kind of PGM metal, and carrier is Al ₂O ₃Or MIOx, the Al that MIIOx modifies ₂O ₃

The precursor compound of above-mentioned active component gold can be metallic gold (silk, bar, piece), gold chloride (HAuCl ₄H ₂O), gold trichloride (AuCl ₃) etc.The precursor compound of auxiliary agent PGM metal can be metal Pd or Pt, PdCl ₂, (NH ₄) ₂PdCl ₄, H ₂PtCl ₆6H2O etc.

The precursor compound of carrier can be nitrate, sulfate, acetate, chloride or the metal alkoxide etc. of corresponding oxide, or in type oxide.The transition metal oxide MIOx that modifies, the predecessor of MIIOx can be nitrate, sulfate, acetate, the chloride of corresponding oxide, and wherein MI is La, and MII is Fe, or Co, or Ni.

Catalyst system therefor of the present invention is with Al ₂O ₃When being carrier, the atomic ratio of Au and Al etc. is 1.0: 1.0 * 10 ³～1.0: 10.Au and atomic ratio (MI+MII) are 1.0: 1.0～1.0: 10, and the atomic ratio of MI and MII is 2.0: 1.0～0.2: 1.0,

The preparation method of catalyst system therefor carrier of the present invention can be a coprecipitation, infusion process.

The coprecipitation of catalyst carrier prepares process: the salting liquid of an amount of MI and MII metal salt solution and carrier metal is added drop-wise to Na in stirring ₂CO ₃(or K ₂CO ₃) in the solution, through leave standstill, separation, roasting, activation processing promptly get required catalyst carrier.

The immersion process for preparing process of composite catalyzing agent carrier can be: with an amount of MI and MII metal salt solution with the carrier of moulding (like Al ₂O ₃) dipping, leave standstill at least 1h after, get composite oxide carrier through dry, roasting.

Deposition-the precipitation method or anion infusion process are adopted in the load of nm of gold.Wherein, Deposition-the precipitation method for the oxide carrier with high-specific surface area of moulding in advance after dried; Inserting temperature is in the active component A u precursor solution of 350K, in continuous stirring, dropwise adds aqueous slkali, and control pH value of solution value is 4.5～8.5 under constant temperature; Until deposition fully, get finished catalyst through sedimentation, filtration, washing, drying, activation processing; Said aqueous slkali is Na ₂CO ₃Or K ₂CO ₃Or the aqueous solution of NaOH or KOH.

The anion infusion process loading process of gold adopts applicant's patented technology (An Lidun, Qi Shixue, rope palm bosom, Weng Yonggen, Zou Xuhua; A kind of preparation method of new load type nano gold catalyst, Chinese invention patent: ZL 03138796.1) preparation.

Catalyst of the present invention carries out CO catalytic oxidation performance evaluation on atmospheric fixed bed reactor, raw materials used gas consists of: CO:0.25-1.0%, all the other are air.

The conversion ratio of CO is obtained by the gas chromatographic analysis result, and the minimum detectable range of CO is measured and is 50ppm.

The short-term stability test of part catalyst under the practical condition of simulation is at room temperature to use atmospheric fixed bed reactor, and unstripped gas is the air that contains 1.0%CO, and residue CO concentration detects with infrared spectrum analyser in the tail gas, and the minimum detectable range of CO is measured and is 1ppm.。

The specific embodiment of the invention is following:

Example 1: measure 0.67mL (NH ₄) ₂PdCl ₄Solution (1.4972g Pd/L) is poured in the 50mL beaker, adds the 2.2mL deionized water, shakes up, and pours 2.006g Al into ₂O ₃Spheroid carrier (through 650 ℃ of roasting 4h) dipping leaves standstill 1h after shaking up, dry 4h under 80-120 ℃, and then, reductase 12 h in 450～470 ℃ of following hydrogen streams is chilled to room temperature naturally.Measure 1.0mL HAuCl ₄Solution (20gAu/L) is poured in the 50mL beaker, adds the 1.5mL deionized water, drips about 0.5ml Na OH (1M) solution; The pH=9 of regulator solution pours the above-mentioned Pd of soaking carrier into dipping, mixing; Leave standstill 2h; Soak 24h with 20ml ammoniacal liquor (pH=10), the elimination stillness of night, be washed till to detect with deionized water and (use AgNO ₃Solution) Cl ^-Ion, 60 ℃ of dry 12h, 300 ℃ of following hydrogen reducing 1h get light brown finished catalyst.

Consist of at unstripped gas: CO:1%; O ₂: 12%; N ₂: 87% (percent by volume), gas volume air speed are 1.5 * 10 ⁴h ^-1Situation under, CO transforms (remaining CO is lower than gas chromatographic detection limit 50ppm) fully for CO ₂Permission minimum response temperature (being called " minimum full conversion temperature ", as follows) be-20 ℃ (253K).

Continuous down in 30 ℃ with the air stream that contains 1%CO through the fixed bed reactors successive reaction 8h of 0.2g catalyst is housed with the gas speed of 300ml/min; The online detection of CO infrared analyzer CO transit dose is less than 100ppm; To successive reaction 10h, CO transit dose≤200ppm.

Example 2: measure 1.34mL (NH ₄) ₂PdCl ₄Solution (1.4972g Pd/L) is poured in the 50mL beaker, adds the dilution of 2.05mL deionized water, shakes up, and pours 2.014g Al into ₂O ₃The spheroid carrier dipping leaves standstill 2h after shaking up, and in 80 ℃ of following dried overnight, then, reductase 12 h in 450～470 ℃ of following hydrogen streams is chilled to room temperature naturally.Measure 1.26mL HAuCl ₄Solution (23.90gAu/L) is poured in the 50mL beaker, adds the 1.35mL deionized water, drips about 0.5ml Na OH (1M) solution; The pH=9 of regulator solution pours the Pd carrier that contains of above-mentioned reduction into dipping, mixing; Leave standstill 2h; Soak 24h with 20ml ammoniacal liquor (pH=10), the elimination stillness of night, be washed till to detect with deionized water and (use AgNO ₃Solution) Cl ^-Ion, 60 ℃ of dried overnight, 300～400 ℃ of following hydrogen reducing 1h get light brown finished catalyst.Adopt the evaluating catalyst condition of example 1, its minimum full conversion temperature is-24.0 ℃.

Example 3: measure 0.67mL (NH ₄) ₂PdCl ₄Solution (7.4851g Pd/L) is poured in the 50mL beaker, adds the dilution of 2.75mL deionized water, shakes up, and pours 2.008g Al into ₂O ₃The spheroid carrier dipping leaves standstill 2h after shaking up, and in 80 ℃ of following dried overnight, then, reductase 12 h in 450～470 ℃ of following hydrogen streams is chilled to room temperature naturally.Measure 1.26mL HAuCl ₄Solution (23.90gAu/L) is poured in the 50mL beaker, adds the 1.30mL deionized water, drips 14 (about 0.5ml) Na OH (1M) solution; The pH=9 of regulator solution pours the Pd carrier that contains of above-mentioned reduction into dipping, mixing; Leave standstill 2h; Soak 24h with 20ml ammoniacal liquor (pH=10), the elimination stillness of night, be washed till nothing with deionized water and (use AgNO ₃Solution) detectable Cl ^-Ion, 60 ℃ of dried overnight, this dry sample of crossing is divided into three parts: a copy of it gets light brown finished catalyst through 300 ℃ of following hydrogen reducing 1h.Adopt the evaluating catalyst condition of example 1, its minimum full conversion temperature is 0 ℃.400 ℃ of following hydrogen reducing 1h of another part warp get light brown finished catalyst.Adopt the evaluating catalyst condition of example 1, its minimum full conversion temperature is 7 ℃.A again through 500 ℃ of following hydrogen reducing 1h, get light brown finished catalyst.Adopt the evaluating catalyst condition of example 1, its minimum full conversion temperature is 22 ℃.

Example 4: measure 0.83mL (NH ₄) ₂PdCl ₄Solution (6.00g Pd/L) is poured in the 50mL beaker, adds the 1.5mL deionized water, with 2M NaOH regulator solution pH=5～6, shakes up, and pours 2.006gAl into ₂O ₃Spheroid carrier (through 650 ℃ of roasting 4h) dipping leaves standstill 1h after shaking up, and in 80 times dried overnight, then, reductase 12 h in 450～470 ℃ of following hydrogen streams is chilled to room temperature naturally.Measure 0.9mL HAuCl ₄Solution (33.4gAu/L) is poured in the 50mL beaker, adds the 1.5mL deionized water, drips the pH=9 of Na OH (1M) solution regulator solution; Pour the Pd carrier that contains of above-mentioned reduction into dipping; Mixing leaves standstill 2h, soaks 24h with 20ml ammoniacal liquor (pH=10); The elimination stillness of night, be washed till with deionized water and (use AgNO ₃Solution) there is not detectable Cl ^-Ion, 60 ℃ of dried overnight, 300 ℃ of following hydrogen reducing 1h get light brown finished catalyst.Adopt the evaluating catalyst condition of example 1, its minimum full conversion temperature is-21.2 ℃.This catalyst is put into and is covered the cover glass bottle, places 2 years in the air under the room temperature, and the evaluating catalyst condition of use-case 1 still can transform CO under the room temperature fully, places after 3 years in the air under the room temperature, still can transform 50%CO under the room temperature.

Example 5: similar with example 1～routine 3 Preparation of catalysts methods, prepared the Pt amount of the planting Pt.1%Au/Al of 0.05%, 0.1%, 0.25% and 0.5% (weight) respectively ₂O ₃Catalyst.2.004g Al ₂O ₃Soak the H of certain volume ₂PtCl ₆6H ₂Behind the O solution, 80 ℃～100 ℃ following dried overnight, reductase 12 h in 500 ℃ of following hydrogen streams is measured 1.00mL HAuCl ₄Solution (20.00g Au/L) is poured in the 50mL beaker, adds the 1.5mL deionized water, drips about 0.5ml Na OH (1M) solution; The pH=9 of regulator solution pours the Pt carrier that contains of above-mentioned reduction into dipping, mixing; Leave standstill 2h; Soak 24h with 20ml ammoniacal liquor (pH=10), the elimination stillness of night, be washed till with deionized water and (use AgNO ₃Solution) there is not detectable Cl ^-Ion, 60 ℃ of dried overnight, 300 ℃ of following hydrogen reducing 1h get light brown finished catalyst.Employing contains CO 1%, H ₂50%, O ₂1%, all the other are the unstripped gas of nitrogen, and other carries out catalytic evaluation with example evaluating catalyst condition of 1 to above-mentioned prepared catalyst, and the Pt carrying capacity is respectively 0.05%, 0.1% and 0.25% catalyst all can at room temperature change into CO with CO fully ₂, and the Pt amount of planting is 0.5% PtAu/Al ₂O ₃The catalyst room temperature can only transform in the unstripped gas 25% CO.

Claims (2)

1. load type gold-PGM alloy catalyst that storge quality is stable, it is characterized in that: active component is Au, and auxiliary agent is Pd or the Pt among the PGM, and carrier is moulding Al ₂O ₃Or the Al of MIOx and MIIOx modification ₂O ₃Composite oxides, the atomic ratio of Au and PGM are 1.0: 1.0～1.0: 1.0 * 10 ^-2, the atomic ratio of Au and MI+MII is 1.0: 1.0～1.0: 10, the atomic ratio of MI and MII is 2.0: 1.0～0.2: 1.0; The atomic ratio of Au and Al is 1.0: 1.0 * 10 ³～1.0: 10; Wherein MI is La, and MII is Fe or Co or Ni, and PGM refers to platinum metal;

Al ₂O ₃Composite oxide carrier is to adopt dipping method or coprecipitation method preparation, Al ₂O ₃Load MIOx is behind the MIIOx, through 800 ℃-1000 ℃ roasting, to generate spinelle or perovskite structure;

Carrier is handled through dry, reduction with the salting liquid of equi-volume impregnating load P GM, becomes " the carrier that load has the PGM metal of dispersion ^M", then, use the deposition-precipitation method or anion infusion process at " carrier ^M" go up the salting liquid of load Au, handle auxiliary agent Pd or Pt and part A u generation Au-PGM alloy catalyst through washing, dry, hydrogen reducing.

2. like the stable load type gold of the said storge quality of claim 1-PGM alloy catalyst, it is characterized in that: the deposition-precipitation method or anion infusion process are adopted in the load of Au; Wherein, Deposition-the precipitation method for the oxide carrier with high-specific surface area of moulding in advance after dried; Inserting temperature is in the active component A u precursor solution of 350K, in continuous stirring, dropwise adds aqueous slkali, and control pH value of solution value is 4.5～8.5 under constant temperature; Until deposition fully, through sedimentation, filtration, washing, drying, hydrogen reducing handle finished catalyst;

Said aqueous slkali is Na ₂CO ₃Or K ₂CO ₃Or the aqueous solution of NaOH or KOH.