CN1032573C - Production method for super strong acids in noble metal/ZrO2/SO2-(4) system - Google Patents

Abstract

The present invention relates to a method for preparing a superstrong acid of a zirconium oxide system. The method comprises: a zirconium salt is dissolved in an ethanol water solution with 1 to 100 wt% of water, the pH value is regulated to 6 to 7 by ammonia water to precipitate zirconium hydroxide, and then, the superstrong acid of the noble metal (in the VIII family)/an SO4 <-2>/ZrO2 system is prepared by the steps of filtering, washing, drying, roasting by impregnating SO4<-2>/ZrO2, impregnating noble metals, etc. The superstrong acid prepared by the method has the advantages of small granularity of the noble metal, good dispersivity, low content of the noble metal, improved catalyst stability and favorable effect on the isomerization reaction of straight chain paraffin.

Description

Noble metal/zirconia/SO 42-The preparation method of system super acids

The invention relates to oxide/SO ₄ ^2-The preparation method of system super acids is specifically about group VIII noble metals/zirconium, titanium, ferriferous oxide/SO ₄ ^2-The preparation method of system super acids.

Super acids is the acid stronger than sulfuric acid, and they are very strong to the positively ionized ability of organic compound, and at room temperature, but their organifying compounds carry out reactions such as alkylation, isomerization.The liquid acid that replaces present industrial use with solid super-strong acid is carried out catalytic reaction, can avoid equipment corrosion to be easy to separate with catalyst with environmental pollution, product.Therefore, solid super acid catalyst be considered to one of promising catalyst in the present petrochemical industry (Kazusli Arata, Advance in Catalysis, Vol.37, P165).Solid super-strong acid is bigger in industrial using value, and at present common have two classes: a class is halogen-containing super acids, because of halogen easily runs off, and etching apparatus, therefore, the solid super-strong acid MxOy/SO of the another kind of non-halogen that now generally begins one's study ₄ ^2-, as ZrO ₂/ SO ₄ ^2-, TiO ₂/ SO ₄ ^2-, Fe ₂O ₃/ SO ₄ ^2-Deng, in addition, also useful Mo and W replace SO ₄ ^2-(catalyst, 1989,31 (6), 477).Super acidic catalyst is mainly used in the linear paraffin isomerization reaction, if supported noble metal can also avoid cracking reaction that (clear 61-68137) take place.People such as T.Hosoi have reported with water as solvent and have prepared Pt/SO ₄ ^2--ZrO ₂The super acids System Catalyst, this catalyst is used for C ₅/ C ₆Isomerization reaction has obtained effect (Symposiumon Preparation and Characterization of Catalysts Present-ed before the division of petroleum Chemistry.INC.Amer-ican Chemical Society, Los Angeles Meeting September 25-30.1988) preferably.

The common feature of above-mentioned several preparation super acids methods is all to be to soak noble metal and SO earlier in the process of preparation super acids ₄ ^2-, and then under 550-700 ℃ of high temperature, carry out roasting, and the super acids bullion content that makes like this is higher, and more than 0.5 heavy %, the granularity of noble metal reaches about 500A as Pt content.Because bullion content height, granularity are big, dispersed bad, metal function can not be given full play to, simultaneously, cracking reaction also takes place easily, be unfavorable for the long-term operation of catalyst, influence life of catalyst.

The objective of the invention is at existing noble metal/oxide/SO ₄ ^2-Improve, reduced bullion content on system super acids preparation method's the basis, make that its granularity diminishes, the dispersed raising, giving full play to of favourable dried metal function makes C ₅/ C ₆Isomerization reaction can be stably, carry out for a long time.

Method provided by the invention is that zirconates is dissolved in the ethanol water that water content is 1-100 heavy %, regulates pH value with ammoniacal liquor, makes PH precipitate zirconium hydroxide under 6-7 situation, filter then, wash, dry, soak SO ₄ ^2-Roasting, soak noble metal, and then make group VIII noble metals/SO ₄ ^2-/ ZrO ₂The system super acidic catalyst, concrete steps are as follows:

1, the preparation of zirconium salt solution: zirconates is dissolved in makes the zirconium salt solution that concentration is 10-30 heavy % in the ethanol water that water content is 1-100 heavy %;

2, under agitation ammonia spirit is added drop-wise in the above-mentioned zirconium salt solution, is 6-7, generates the zirconium hydroxide precipitation, leave standstill, wear out, filter, precipitation is washed till no Cl with deionized water up to PH ^-, in 100-120 ℃ of oven dry, porphyrize to 40-80 order;

3, soak SO with saturated infusion process ₄ ^2-, make SO in the catalyst ₄ ^2-Content is 2-15 heavy %, preferably 4-13 weighs %, drying;

4, in 550-700 ℃ of roastings 0.5-5 hours;

5, soak noble metal with saturated infusion process, making in the catalyst bullion content is 0.1-1.5 heavy %, preferably 0.1-1.0 heavy %, drying;

6, give processing 0.5-3 hours in 250-550 ℃;

7, at H ₂Reduced 0.5-2 hours in 200-350 ℃ under the atmosphere.

The said zirconates of the present invention is meant the zirconates that can be dissolved in alcohol-aqueous solution, acetone, benzole soln, as ZrOCl ₂8H ₂O, ZrO (NO ₃) ₂, Zr (NO ₃) ₄Deng, the precursor of noble metal is H ₂PtCl ₆Solution or with PdCl ₂Be dissolved in the H that makes in the hydrochloric acid ₂PdCl ₄Solution also can be H ₂PtCl ₆Ethanol solution.

The said preparation method of the present invention also can be used for Fe ₂O ₃/ SO ₄ ^2-, TiO ₂/ SO ₄ ^2-, SnO ₂/ SO ₄ ^2-Preparation Deng ultra-strong acid of oxide system.

The said ethanol of the present invention can replace with other the alcohol that can dissolve zirconates, also can replace with acetone and benzene.

Group VIII noble metals/the SO that adopts method provided by the invention to make ₄ ^2-/ ZrO ₂The system super acids has isomerization activity and stability preferably than the super acids of the same system for preparing with prior art, and bullion content is low, granularity is little, dispersiveness is high, help the performance of metal function, improved the stability of catalyst, the isomerization reaction of linear paraffin has been had effect preferably.

Following example will the invention will be further described.

Example 1

With 40 gram ZrOCl ₂8H ₂O (Beijing Chemical Plant, AR descend together) is dissolved in the ethanolic solution that water content is 50 heavy %, makes to contain ZrOCl ₂Be the solution of 20 heavy %, the ammonia spirit with 4 heavy % is added drop-wise to ZrOCl then ₂In the solution,, generate the zirconium hydroxide precipitation, left standstill aging 2 hours, be washed till no CL with deionized water up to PH=6-7 ^-, in 100-120 ℃ of dryings 24 hours, porphyrize to 40-80 order made the zirconium hydroxide powder, soaked 10 heavy % (NH ₄) ₂SO ₄2.5 milliliters of solution, oven dry under agitation in 600 ℃ of roastings 2 hours, is soaked 0.5 heavy %H again ₂PtCl ₆2 milliliters of solution, drying is given in 300 ℃ and to be handled 1 hour, in 300 ℃ at H ₂Reduction is 1 hour under the atmosphere, makes catalyst A.

Example 2

The preparation method just soaks 20 heavy % (NH with example 1 ₄) ₂SO ₄2.5 milliliters of solution soak 1 heavy %H ₂PtCl ₆1.5 milliliters of solution make catalyst B.

Example 3

The preparation method just soaks the H of 1 heavy % with example 2 ₂PtCl ₆2.0 milliliters of solution make catalyst C.

Example 4

The preparation method just soaks the H of 1 heavy % with example 2 ₂PtCl ₆1.5 milliliters of ethanol solutions, air-dry, make catalyst D.

Example 5

The preparation method just gives at 400 ℃ and handling 1 hour with example 2, makes catalyst E.

Example 6

The preparation method just soaks the H of 2 heavy % with example 2 ₂PdCl ₄2 milliliters of solution give in 300 ℃ and to handle 1 hour, again in 250 ℃ at H ₂Reduction is 1 hour under the atmosphere, makes catalyst F.

Example 7

The preparation method is with example 3, just zirconates is dissolved in the deionized water of 100 heavy % and makes zirconium salt solution, soaks 30 heavy % (NH ₄) ₂SO ₄2.5 milliliters of solution. make catalyst G.

Example 8

The preparation method just is the ethanol water dissolving ZrOCl of 10 heavy % with water content with example 2 ₂8H ₂O makes catalyst H.

Example 9

The preparation method just is the ethanol water dissolving ZrOCl of 40 heavy % with water content with example 2 ₂8H ₂O makes catalyst I.

Comparative Examples 1

The preparation method is just soaking SO with example 2 ₄ ^2-Before, soak 1 heavy %H earlier ₂PtCl ₆2.5 milliliters of solution, drying is soaked 20 heavy % (NH again ₄) ₂SO ₄2.5 milliliter, oven dry is in 600 ℃ of roastings 2 hours, at 300 ℃ of H ₂Reduction is 1 hour under the atmosphere, makes catalyst J.

Example 10

Composition and noble metal granule size with conventional chemical analytic approach and ESEM method mensuration catalyst adopt the n-butylamine titration method to measure the acid strength Ho of catalyst, the results are shown in Table 1.

(n-butylamine titration method: make indicator with nitrobenzene, make solvent) with the benzole soln of nitrobenzene.

Table 1

The catalyst numbering	Water content in the ethanolic solution (heavy %)	Bullion content		SO 4 2-The heavy % of content	Acid strength (Ho)	Noble metal granularity (A)
							Pt(Pd)	Heavy %
		A B C D E F G H I J	50 50 50 50 50 50 100 10 40 50						Pt Pt Pt Pt Pt Pd Pt Pt Pt Pt	0.2 0.3 0.4 0.3 0.3 0.8 0.4 0.2 0.2 0.5	4 8 8 8 8 8 13 8 8 8	＜-12.14 ＜-12.14 ＜-12.14 ＜-12.14 ＜-1 2.14 ＜-12.14 ＜-12.14 ＜-12.14 ＜-12.14 ＜-12.14	～85 ～100 100-150 - - ～200 - - - ～500

Table 2

The catalyst numbering	Pulse number	n-C 6Conversion ratio (mole)	Product distribution (mole %)
					Pyrolysis product	Isomerized products
			A	1 2 3			42.3 38.5 40.1	2.2 2.0 1.9	40.1 36.5 38.2
B	1 2 3	41.3 41.1 41.3			2.2 2.0 2.1	39.1 39.1 39.2
			C	1 2 3			21.7 25.8 28.8	2.2 2.2 2.2	19.5 23.6 26.6
D	1 2 3	38.5 37.5 36.5			2.0 1.9 1.9	36.5 35.6 34.6
			E	1 2 3			46.8 45.2 43.3	2.5 2.2 2.0	44.3 43.0 41.3
F	1 2 3	48.5 41.6 41.1			6.0 2.8 2.6	42.5 38.8 38.5
			G	1 2 3			30.5 30.2 29.5	1.8 1.6 1.6	28.7 28.6 27.9
H	1 2 3	43.5 42.3 40.0			2.0 2.1 1.9	41.5 40.2 38.1
			I	1 2 3			42.5 40.0 41.0	2.1 2.2 2.2	40.4 37.8 38.8
J	1 2 3	66.3 37.0 38.1			38.4 3.2 1.6	27.9 33.8 36.5

Example 11

The super acids of estimating the present invention's preparation is to n-C ₆Isomerization reaction activity.

On the pulse reaction device, with n-C ₆Be raw material, estimate the isomerization reaction activity of super acidic catalyst A-J.Reaction condition is: 170 ℃ of reaction temperatures, 40-80 purpose catalyst filling, 0.4 gram, carrier gas H ₂Flow is 50 ml/min, and reaction result sees Table 2.

As can be seen from Table 2: at 170 ℃, though very high with the sample J activity of prior art preparation, very fast cracking inactivation, the super acidic catalyst A-I with the present invention's preparation is isomerized products entirely almost under similarity condition, and reacts highly stable.Reaction result shows, not only reaction stability is good for the super acidic catalyst for preparing with the present invention, reduced bullion content simultaneously, the noble metal granularity diminishes, the decentralization height, help the performance of metal function, improved the stability of catalyst, the isomerization reaction of linear paraffin has been had effect preferably.

Claims (7)

1, a kind of preparation method who contains the zirconia super acidic catalyst of group VIII noble metals is characterized in that:

(1) zirconates is dissolved in makes the solution that concentration is 10-30 heavy % in the ethanol water that water content is 1-100 heavy %;

(2) under agitation ammoniacal liquor being added drop-wise in the zirconium salt solution, is 6-7 up to PH, generates the zirconium hydroxide precipitation, leaves standstill, aging, filters, and with deionized water precipitation is washed no Cl ^-, in 100-120 ℃ of oven dry, porphyrize to 40-80 order;

(3) soak SO with saturated infusion process ₄ ^2-, make SO in the catalyst ₄ ^2-Content is 2-15 heavy % dryings;

(4) in 550-700 ℃ of roastings 0.5-5 hours;

(5) soak noble metal with saturated infusion process, making in the catalyst bullion content is the heavy % of 0.1-1.5, drying;

(6) give processing 0.5-3 hours in 250-550 ℃;

(7) at H ₂Reduced 0.5-2 hours in 200-350 ℃ under the atmosphere.

2, method according to claim 1 is characterized in that soaking SO according to (3) ₄ ^2-, make SO in the catalyst ₄ ^2-Content is 4-13 heavy %.

3, method according to claim 1, it is characterized in that soaking noble metal according to (5), to make in the catalyst bullion content be 0.1-1.0 heavy %.

4, method according to claim 1 is characterized in that said zirconates is ZrOCl ₂8H ₂O, ZrO (NO ₃) ₂, Zr (NO ₃) ₄

5, method according to claim 1 is characterized in that said noble metal is Pt, Pd or the mixture of the two.

6, method according to claim 1 is characterized in that said noble metal source is H ₂PtCl ₆Solution or with PdCl ₂Be dissolved in the H that makes in the hydrochloric acid ₂PdCl ₄Solution also can be H ₂PtCl ₆Ethanol solution.

7, method according to claim 1 is characterized in that said SO ₄ ^2-The source is (NH ₄) ₂SO ₄Or H ₂SO ₄Solution.