INORGANIC SOLID SILICON-BASED SULFONIC ACID AND/OR PHOSPHORIC ACID CATALYST, PREPARATION METHOD THEREFOR, AND APPLICATION THEREOF

Abstract

A preparation method and use of a novel pure inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalytic material are disclosed. The surface hydroxyl-rich metasilicic acid is used as the raw material, and by using a sulfonating reagent and/or phosphoric acid, the sulfonic acid group and/or the phosphoric acid group are bonded to the inorganic silicon material by chemical bonding to obtain a pure inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalytic material. The catalytic material can be widely used in many acid-catalyzed organic reactions such as isomerization, esterification, alkylation, hydroamination of olefins, condensation, nitration, etherification, multi-component reactions and oxidation reactions. The inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalytic material of the present invention has the advantages of high acid amount, high activity, good hydrothermal stability, no swelling, simple preparation, low cost, no pollution, no corrosion, easy separation and reusability.

Claims

1.-14. (canceled)

15. An inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalyst (h-SSA) in granular form or powder form, comprising: a substrate component (A): a silicon-containing substrate without sulfonic acid group(s) and/or phosphoric acid group(s); and a silicon-based acid component (B): inorganic silicon-based sulfonic acid and/or phosphoric acid containing sulfonic acid group(s) and/or phosphoric acid group(s); wherein the substrate component (A) in the above-mentioned silicon-based sulfonic acid and/or phosphoric acid catalyst (h-SSA) includes or is selected from one or two or three of the following silicon-containing substrate components: (1) metasilicic acid; (2) silica gel, and (3) silica; wherein the inorganic silicon-based sulfonic acid and/or phosphoric acid containing a sulfonic acid group(s) and/or a phosphoric acid group(s) includes a compound of the general formula (I), a compound of the general formula (II) and a compound of the general formula (III): ##STR00009## in the above formulae, -AG.sub.1 and -AG.sub.2 are each independently —O—SO.sub.3H, —O—PO.sub.3H.sub.2 or —OH, and -AG.sub.1 and -AG.sub.2 are not both —OH; wherein the acid amount of the solid acid catalyst (h-SSA) is 0.4-7.0 mmol/g; and wherein the average particle size of the solid acid catalyst (h-SSA) is 15-700 μm.

16. The catalyst according to claim 15, wherein the acid amount of the solid acid catalyst (h-SSA) is 0.6-5.8 mmol/g; and/or the average particle size of the solid acid catalyst (h-SSA) is 30-550 μm.

17. The catalyst according to claim 15, wherein the acid amount of the solid acid catalyst (h-SSA) is 0.8-5.0 mmol/g; and/or the average particle size of the solid acid catalyst (h-SSA) is 40-450 μm.

18. The catalyst according to claim 15, wherein the silicon-based acid component (B) comprises: 60-100 wt % of compounds of general formula (I); 0-40 wt % of compounds of the general formula (II); and 0-30 wt % of compounds of general formula (III); wherein the weight percent is based on the total weight of the silicon-based acid component (B).

19. The catalyst according to claim 18, wherein the silicon-based acid component (B) comprises: 70-100 wt % of compounds of general formula (I); 0-30 wt % of compounds of the general formula (II); and 0-20 wt % of compounds of general formula (III); wherein the weight percent is based on the total weight of the silicon-based acid component (B).

20. The catalyst according claim 15, wherein: the sum of the weights of the compound of the general formula (I), the compound of the general formula (II) and the compound of the general formula (III) is 85-100 wt %, based on the total weight of the silicon-based acid component (B); and/or the sum of the weights of components (A) and (B) is 90-100 wt % of the total weight of the catalyst (h-SSA); and/or the ratio of the weight of the silicon-based acid component (B) to the substrate component (A) is: 0.02-8:1; and/or the average particle size of the solid acid catalyst (h-SSA) is 50-350 μm; and/or the acid amount of the solid acid catalyst (h-SSA) is 1.0-4.8 mmol/g.

21. The catalyst according to claim 15, wherein: -AG.sub.1 and -AG.sub.2 are each independently —O—SO.sub.3H or —OH, or —O—PO.sub.3H.sub.2 or —OH, and -AG.sub.1 and -AG.sub.2 are not both —OH; and/or the acid amount of the solid acid catalyst (h-SSA) is 1.0-5.0 mmol/g, and the average particle size of the solid acid catalyst (h-SSA) is 45-400 μm; and/or the sum of the weights of the compound of the general formula (I), the compound of the general formula (II) and the compound of the general formula (III) is 90-100 wt %, based on the total weight of the silicon-based acid component (B); and/or the sum of the weights of components (A) and (B) is 95-100 wt % of the total weight of the catalyst (h-SSA).

22. The catalyst according to claim 15, wherein: the crushing strength of the solid acid catalyst particles (h-SSA) in which the silicon substrate is a silica substrate is in the range of 165-260N; and/or the alkali metal content of the silica substrate in the solid acid catalyst (h-SSA) is 0-300 ppm; and/or the BET specific surface area of the solid acid catalyst (h-SSA) is 50-800 m.sup.2/g; and/or the pore volume of the solid acid catalyst (h-SSA) is 50-700 cm.sup.3/g; and/or the average pore diameter of the solid acid catalyst (h-SSA) is 4-100 nm; and/or the sum of the weights of the compound of the general formula (I), the compound of the general formula (II) and the compound of the general formula (III) is 95-100 wt %, based on the total weight of the silicon-based acid component (B); and/or the sum of the weights of components (A) and (B) is 98-100 wt % of the total weight of the catalyst (h-SSA).

23. A method for preparing the inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalyst according to claim 15, comprising: (B) sulfonation and/or phosphorylation of metasilicic acid: reacting the granular metasilicic acid (H.sub.2SiO.sub.3) raw material with a sulfonating agent and/or a phosphorylating agent, separating the resulting reaction product and washing with water or with organic solvent, and then drying to obtain dry inorganic solid silicon-based sulfonic acid and/or phosphoric acid particles (h-SSA); wherein the amount of the sulfonating agent and/or phosphorylating agent relative to metasilicic acid is sufficient so that the acid amount of the dried but unbaked solid acid catalyst (h-SSA) is 0.4-7.0 mmol/g.

24. The method of claim 23, further comprising: (C) baking: baking the dry granular silicon-based sulfonic acid and/or phosphoric acid solid obtained in step (B) to obtain an inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalyst (h-SSA); wherein the baking temperature is 120-600° C.

25. The method of claim 24, further comprising: (A) preparation of granular metasilicic acid H.sub.2SiO.sub.3 raw material: carrying out an ion exchange reaction or a hydrolysis reaction of silicon source and inorganic acid to obtain orthosilicic acid (H.sub.4SiO.sub.4) gel or sol; allowing the orthosilicic acid gel or sol to stand for crystallization to obtain a solution containing particulate orthosilicic acid (H.sub.4SiO.sub.4) gel, filtering the solution and washing the resulting filter cake with water until the filtrate was neutral, and drying the separated gel to obtain dry granular or powdery metasilicic acid (H.sub.2SiO.sub.3) raw material.

26. The method according to claim 25, wherein: the silicon source in step (A) is one or more of silicate salt, silicate ester and silica gel; and/or the inorganic acid used in step (A) is one or more of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid; and/or in step (A), the molar ratio of silicon source material and inorganic acid is 0.01-2.0:1; and/or in step (B), the molar ratio of the metasilicic acid to the sulfonating agent and/or phosphorylating agent is 0.01˜4.0:1; and/or in step (B), the temperature of the sulfonation reaction is 20° C. to 200° C.; and/or the above step (B) or step (A) is carried out under stirring or under the action of stirring plus ultrasonic waves or microwaves; and/or the baking temperature in step (C) is 200-480° C.

27. A method of preparing the inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalyst according to claim 15, comprising: allowing the silicon source and the inorganic acid to carry out ion exchange reaction or hydrolysis reaction to obtain orthosilicic acid (H.sub.4SiO.sub.4) gel or sol; standing the orthosilicic acid gel or sol for crystallization to obtain a solution containing granular orthosilicic acid (H.sub.4SiO.sub.4) gel, filtering the solution and washing the resulting filter cake with water until the filtrate is neutral, drying the separated gel to obtain a dry granular or powdery metasilicic acid (H.sub.2SiO.sub.3) raw material; then, sulfonating and/or phosphorylating the dried granular metasilicic acid (H.sub.2SiO.sub.3) raw material with a sulfonating agent and/or a phosphorylating agent, filtering the resulting reaction mixture and washing the filter cake with water or organic solvent until the filtrate is neutral, drying the isolated granular sulfonated and/or phosphorylated solid, thereby obtaining a dry inorganic solid silicon-based sulfonic acid and/or phosphoric acid powder; and finally, baking the inorganic solid acid powder to obtain a solid acid catalyst (h-SSA).

28. Use of the inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalyst according to claim 15, wherein the catalyst is used for isomerization, esterification, alkylation, hydroamination of olefins, condensation reaction, nitration reaction, etherification reaction, amination reaction of alcohol, reaction to prepare β-enaminone, multi-component reaction, oxidation reaction and addition reaction.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0129] FIG. 1 is a FT-IR chart of infrared characterization of the inorganic solid silicon-based sulfonic acid catalyst of Example 1 of the present invention. 1: metasilicic acid; 2: silicon-based sulfonic acid.

[0130] FIG. 2 is the N.sub.2 adsorption-desorption diagram (A) and pore size distribution diagram (B) of the inorganic solid silicon-based sulfonic acid catalyst of Example 1 of the present invention. 1: metasilicic acid; 2: silicon-based sulfonic acid.

[0131] FIG. 3 is a pyridine adsorption infrared spectrogram of the inorganic solid silicon-based sulfonic acid catalyst of Example 1 of the present invention. 1: metasilicic acid; 2: silicon-based sulfonic acid.

[0132] FIG. 4 is the NH.sub.3˜TPD (ammonia temperature programmed desorption) spectrum of the inorganic solid silicon-based sulfonic acid catalyst of Example 1 of the present invention. 1: metasilicic acid; 2: silicon-based sulfonic acid.

[0133] FIG. 5 is a thermogravimetric diagram of the inorganic solid silicon-based sulfonic acid catalyst of Example 1 of the present invention. 1: metasilicic acid; 2: silicon-based sulfonic acid.

[0134] FIG. 6 is a reaction process for preparing silicon-based sulfonic acid. a: silicate salt; b: silicate ester; c: silica gel; 1: metasilicic acid; 2: solid silicon-based sulfonic acid catalyst material; 3: inorganic acid; 4: sulfonating reagent.

[0135] FIG. 7 is a XRD pattern of the dried but unbaked solid acid catalyst of Example 1. 1: silicon-based sulfonic acid powder (unbaked); 2: metasilicic acid powder (unbaked).

[0136] FIG. 8 is a XRD pattern of the baked solid acid catalyst of Example 1. 1: baked metasilicic acid powder; 2: baked silicon-based sulfonic acid powder.

[0137] FIGS. 9 and 10 are the particle size distributions of the metasilicic acid and silicon-based sulfonic acid obtained in Example 1, respectively.

[0138] FIG. 11 is a scanning electron microscope (SEM) photograph of the baked inorganic solid silicon-based sulfonic acid particle product of Example 1.

[0139] FIG. 12 is a FT-IR spectrum of dried metasilicic acid and baked inorganic solid silicon-based sulfonic acid particles in Example 2. 1: silica powder; 2: metasilicic acid powder; 3: baked silicon-based sulfonic acid powder.

[0140] FIG. 13 is a FT-IR spectrum of the phosphorylated inorganic solid metasilicic acid powder of Example 20 and the sulfonated/phosphorylated inorganic solid metasilicic acid powder of Example 21. 1: metasilicic acid powder, 2: phosphorylated metasilicic acid powder, 3: sulfonated/phosphorylated metasilicic acid powder.

[0141] FIG. 14 is the particle size distribution of the powdered silicon-based sulfonic acid particles (T2B) of Comparative Example 3.

[0142] FIG. 15 is a XRD pattern of the solid silicon-based sulfonic acid of Comparative Example 3.

DETAILED DESCRIPTION OF THE INVENTION

[0143] The following examples describe preparation methods and uses of inorganic solid silico-sulfonic acid catalytic materials (catalysts for short), but the present invention is not limited to these examples.

[0144] 1. Method of Measuring Acid Amount of Particulate Silicon-Based Sulfonic Acid Catalyst

[0145] Weigh approximately 0.5 g (accurate to 0.0001) of the vacuum dried solid silico-sulfonic acid catalyst (not containing adsorbed sulfonic acid and/or phosphoric acid), add to a 250 mL Erlenmeyer flask, then add 25 mL of a freshly prepared saturated NaCl solution, shake the Erlenmeyer flask well, seal the mouth of the Erlenmeyer flask with plastic wrap, and then shake well every 4 h, after ion exchange for 24 h, add 2˜3 drops of phenolphthalein indicator and titrate the amount of acid with 0.1 mol/L NaOH standard solution. For each solid acid, titrate in parallel at least 3 times with relative error control within 1%. Record the volume of NaOH consumed, calculate the amount of acid in mmol H+/g according to the formula below.

[00001]$\mathrm{acid}\mathrm{amount}=\frac{C_{\mathrm{NaOH}}\times V_{\mathrm{NaOH}}}{m}.$

[0146] 2. Method of Measuring Crush Strength

[0147] According to the China National Standard GB/T 3780.16-1983 method, determine crush strength of solid acid catalyst particles, using Model DL5 smart particle strength meter.

[0148] Measurement procedure: measuring the particle size of the prepared sample granules individually and then placing the sample granules on sample platform of Model DL5 smart particle strength meter, applying force to break them, recording applied load at which granules crush, and determining their crush strength results.

Example 1

[0149] 50 g of sodium silicate nonahydrate was thoroughly dissolved in 400 mL of deionized water, so as to obtain sodium silicate solution. Then 200 mL of 1.8 mol/L hydrochloric acid solution was added to the sodium silicate solution (molar ratio of sodium silicate to hydrochloric acid was 0.5), an ion exchange reaction was performed at room temperature, controlling pH to 5˜6, and orthosilicic acid (H.sub.4SiO.sub.4) gel was obtained. The resulting gel was then crystallized by standing at 60° C. for 12 hours, re-filtered, and washed with water, until the filtrate was neutral. Finally the obtained gel solid was dried under vacuum at 110° C. for 12 h, obtaining solid powder metasilicic acid (H.sub.2SiO.sub.3), the specific surface area thereof was measured to be 293 m.sup.2/g. 5 g of metasilicic acid powder with an average particle size of 90 μm was added to 100 mL of concentrated sulfuric acid (concentration 98 wt %), stirred, and sulfonated at 130° C. for 6 h, then cooled to room temperature, filtered, and the filter cake was washed with deionized water until the filtrate was neutral, the resulting white solid powder (wet solid) was dried under vacuum at 110° C. for 5 h, the dried inorganic solid silicon-based sulfonic acid powder (crush strength 105 N) was obtained. Finally, the dried sulfonated solid powder was baked under nitrogen atmosphere for 3 h at 200° C., resulting in inorganic solid silicon-based sulfonic acid catalytic material (baked inorganic solid silicon-based sulfonic acid) (crush strength 185 N) having an acid amount of 3.419 mmol/g and a BET specific surface area of 286 m.sup.2/g. Structural characterization of the catalytic material was shown in FIGS. 1-5.

Example 2

[0150] 280 mL of a 1.8 mol/L hydrochloric acid solution was dropped into 21 g of an ethanol solution of tetraethyl orthosilicate (0.1 mol) (molar ratio of silicate to hydrochloric acid was 0.2), the hydrolysis reaction was carried out at 20° C., controlling pH to 5˜6, and orthosilicic acid (H.sub.4SiO.sub.4) gel was obtained. This gel was then crystallized by standing at 60° C. for 12 hours, re-filtered and washed, until the filtrate was neutral. Finally the obtained gel solid was dried under vacuum at 110° C. for 12 h, obtaining solid powder metasilicic acid (H.sub.2SiO.sub.3), the specific surface area thereof was measured to be 305 m.sup.2/g. 5 g of metasilicic acid powder with an average particle size of 88 μm was added to 100 mL of concentrated sulfuric acid, stirred, and sulfonated at 130° C. for 6 h, then cooled to room temperature, filtered, and the filter cake was washed with deionized water until the filtrate was neutral, the obtained white solid powder was dried under vacuum at 110° C. for 5 h, and finally the dried sulfonated solid powder was baked under nitrogen atmosphere at 200° C. for 3 h to obtain an inorganic solid silicon-based sulfonic acid catalytic material having an acid amount of 3.532 mmol/g and a BET specific surface area of 295 m.sup.2/g.

Comparative Example 1

[0151] Silica gel sulfonic acid catalytic material was prepared using a silica gel by a direct sulfonation method. 5 g of 90 μm of silica gel was added to 100 mL of concentrated sulfuric acid for direct sulfonation, stirred, and sulfonated at 130° C. for 6 h, then cooled to room temperature, filtered, and the filter cake was washed with deionized water until the filtrate was neutral; the resulting white solid powder was dried under vacuum at 110° C. for 5 h and finally the dried sulfonated solid powder was baked under nitrogen atmosphere for 3 h at 200° C. to obtain an inorganic solid silica gel sulfonic acid catalytic material having a measured acid amount of only 0.133 mmol/g, a BET specific surface area of 185 m.sup.2/g, an average particle size of 85 μm and a crush strength of 165 N.

Example 3 (Application Example—Catalyst Stability)

[0152] Stability investigation of inorganic solid silicon-based sulfonic acid catalytic material. The inorganic solid silicon-based sulfonic acid catalytic material of Example 1 described herein was selected for cyclohexanone oxime liquid phase Beckmann rearrangement system, the service life thereof was investigated, the catalytic material was operated at a reaction temperature of 130° C. for 136 h, there was no significant drop in cyclohexanone oxime conversion and caprolactam selectivity, with cyclohexanone oxime conversion maintained at 98% and caprolactam selectivity maintained at 99%, and little drop in acid amount measured after the reaction.

Comparative Example 2 (Application Example—Catalyst Stability)

[0153] Stability investigation of organic-type solid sulfonic acid catalytic material. Commercial sulfonic acid resin of type 742B was selected for cyclohexanone oxime liquid phase Beckmann rearrangement system. The results showed that, after the catalyst was operated at 130° C. for 12 hours, the catalyst substantially lost activity, and the catalyst swelled significantly in the reaction solution, the structure thereof was compromised, and had a significant drop in acid amount, the acid amount drops to only 0.05 mmol/g.

Example 4

[0154] The experimental procedure was as in Example 1, except that microwave field was added during ion exchange reaction, and resulting inorganic solid silicon-based sulfonic acid catalytic material was measured to have acid amount of 4.215 mmol/g. The silicon-based sulfonic acid particles had average particle size of 103 μm and crush strength of 198 N.

Example 5

[0155] The experimental procedure was as in Example 1, except that microwave field was added during metasilicic acid sulfonation, and resulting inorganic solid silicon-based sulfonic acid catalytic material was measured to have acid amount of 4.932 mmol/g. The particles had average particle size of 96 μm and crush strength of 201 N.

Example 6

[0156] The preparation procedure was as in Example 1, except that molar ratio of sodium silicate nonahydrate to hydrochloric acid was 1.0, and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 2.986 mmol/g. The particles had average particle size of 101 μm and crush strength of 195 N.

Example 7

[0157] The preparation procedure was as in Example 2, except that molar ratio of silicate ester to hydrochloric acid was 1.0, and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 3.215 mmol/g. The particles had average particle size of 97 μm and crush strength of 209 N.

Example 8

[0158] The preparation procedure was as in Example 2, except that temperature of ion exchange reaction was 60° C., and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 3.053 mmol/g. The particles had average particle size of 96 μm and crush strength 198 N.

Example 9

[0159] The preparation procedure was as in Example 2, except that temperature of hydrolysis reaction was 50° C., and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 3.648 mmol/g. The particles had average particle size of 102 μm and crush strength of 188 N.

Example 10

[0160] The preparation procedure was as in Example 1, except that inorganic acid used was nitric acid, and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 3.421 mmol/g. The particles had average particle size of 99 μm and crush strength of 185 N.

Example 11

[0161] The preparation procedure was as in Example 1, except that metasilicic acid sulfonation reagent was chlorosulfonic acid, and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 3.515 mmol/g. The particles had average particle size of 84 μm and crush strength of 179 N.

Example 12

[0162] The preparation procedure was as in Example 1, except that metasilicic acid sulfonation reagent was sulfur trioxide, and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 3.815 mmol/g. The particles had average particle size of 78 μm and crush strength of 168 N.

Example 13

[0163] The preparation procedure was as in Example 1, except that pH of gel solution was maintained at 8, and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 2.056 mmol/g. The particles had average particle size of 88 μm and crush strength of 205 N.

Example 14

[0164] The preparation procedure was as in Example 1, except that temperature of gel crystallization was 80° C., and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 1.988 mmol/g. The particles had average particle size of 92 μm and crush strength 187 N.

Example 15

[0165] The preparation procedure was as in Example 1, except that gel drying temperature was changed to 120° C., and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 1.885 mmol/g. The particles had average particle size of 99 μm and crush strength of 194 N.

Example 16

[0166] The preparation procedure was as in Example 1, except that metasilicic acid was sulfonated at temperature of 100° C., and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 2.568 mmol/g. The baked catalyst particles had average particle size of 108 μm and crush strength 198 N.

Example 17

[0167] The preparation procedure was as in Example 1, except that metasilicic acid was sulfonated at temperature of 140° C., and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 3.058 mmol/g. The particles had average particle size of 95 μm and crush strength of 191 N.

Example 18

[0168] The preparation procedure was as in Example 1, except that solid silicon-based sulfonic acid catalytic material was dried at temperature of 90° C., and resulting inorganic solid silicon-based sulfonic acid catalytic material with acid amount of 3.357 mmol/g. The particles had average particle size of 96 μm and crush strength of 188 N.

Example 19 (Application Example)

[0169] The inorganic solid silicon-based sulfonic acid catalytic material of Example 1 according to the present invention can also be used in other acid catalyzed reactions, such as isomerization, hydroamination, alkylation, multi-component, esterification, etherification, nitration, oxidation, addition reaction and the like, with superior results as shown in Table 1.

TABLE-US-00001 TABLE 1 Catalytic Reaction Results of Inorganic Solid Silicon-based sulfonic Acid Catalytic Material Reaction raw Reaction Conversion Target Product Reaction type material Conditions rate (%) Selectivity (%) Isomerization Ethylbenzene Temperature 90.2 Xylene: reaction 150° C., 99.5 time 4 h Isomerization Cyclohexanone Temperature 98.7 Caprolactam reaction oxime 130° C., 99.0 time 4 h Hydroamination Cyclohexene + Temperature 95.5 Dicyclohexylamine: reaction cyclohexylamine 260° C., 98.9 dwell time 13.5 seconds Alkylation Phenol + Temperature 90.8 P-Methylphenol: reaction Methanol 200° C., 85.8 time 6 h Esterification Pyrogallic acid + Temperature 96.5 Ethyl pyrogallate: ethanol 120° C., 99.5 time 2 h Multicomponent Aldehydes, amines Temperature 91.4 2,3- reaction and 80° C., dihydroquinazoline: trimethylsilanitrile time 3 h 96.8 Etherification Ethanol Temperature 88.5 Diethyl ether: 140° C., 98.7 time 5 h Nitration Toluene + Oxygen aeration, 93.7 P-Nitrotoluene: NO.sub.2 temperature 90.5 30° C., time 2 h Oxidation Dihydropyridine + Temperature 98.6 Pyridine: reaction sodium nitrite 160° C., 97.8 time 7 h Oxidation Benzyl alcohol + Temperature 85.9 Benzaldehyde: reaction molecular oxygen 150° C., 96.9 time 2 h Addition Cyclohexene + Temperature 95.6 Cyclohexyl reaction methanol 130° C., methylether: time 4 h 98.7

Example 20—Preparation of Inorganic Solid Silico-Phosphoric Acid Catalyst

[0170] 3 g of solid metasilicic acid powder (average particle size 90 μm) was added in a 50 mL two-necked round bottom flask with a stir bar, mounting the round bottom flask on an iron stand, 30 mL phosphoric acid (concentration 85 wt %) was added with a constant pressure funnel, a thermometer was inserted below the liquid level, the another port of the flask was connected to a condensing and refluxing device, the flask was sealed, placed in a thermostatic magnetic stirrer, refluxing at 100° C. for 4 h. After completion of the reaction, the solution and catalyst in the round bottom flask were poured into a sand core funnel to suction filtration, then washed with distilled water until the last drop of filtrate was neutral. The upper catalyst was taken out, and then put into a vacuum drying oven at 110° C. for 12 hours, phosphorylated inorganic solid metasilicic acid powder was obtained (FT-IR spectrum thereof was shown in FIG. 13, curve 2). Finally, the dried solid powder was baked under nitrogen atmosphere for 3 h, the baking temperature was 200° C., and resulting inorganic solid silicon-based phosphoric acid catalyst was measured to have acid amount of 2.885 mmol/g, a specific surface area of 268 m.sup.2/g, an average particle size of about 89.7 μm, and a crush strength of 185 N. For elemental analysis of the catalyst, the content of alkali metals (e.g., sodium and potassium) was below the detection limit (below 3 ppm), and the content of alkaline earth metals (e.g., calcium and magnesium) was below the detection limit.

Example 21—Preparation of Inorganic Solid Silicon-Based Sulfonic Acid/Phosphoric Acid Catalyst

[0171] 3 g of solid metasilicic acid powder (average particle size 90 μm) was added in a 50 mL two-necked round bottom flask with a stir bar, mounting the round bottom flask on an iron stand, 15 mL phosphoric acid (concentration 85 wt %), 15 mL concentrated sulfuric acid (concentration 98 wt %) were added sequentially with a constant pressure funnel, a thermometer was inserted below the liquid level, the other port of the flask was connected to a condensing and refluxing unit, the flask was sealed, placed in a thermostatic magnetic stirrer, refluxing at 100° C. for 4 h. After completion of the reaction, the solution and catalyst in the round bottom flask were poured into a sand core funnel to suction filtration, then washed with distilled water until the last drop of filtrate was neutral. The upper catalyst was taken out, and then put into a vacuum drying oven at 110° C. for 12 hours, sulfonated/phosphorylated inorganic solid metasilicic acid powder was obtained (FT-IR spectrum thereof was shown in FIG. 13, curve 3). Finally, the dried solid powder was baked under nitrogen atmosphere for 3 h, the baking temperature was 200° C., and resulting inorganic solid silicon-based sulfonic acid/phosphoric acid catalyst was measured to have acid amount of 3.685 mmol/g, a specific surface area of 305 m.sup.2/g, an average particle size of about 89.3 μm, and a crush strength of 186 N. For elemental analysis of the catalyst, the content of alkali metals (e.g., sodium and potassium) was below the detection limit, and the content of alkaline earth metals (e.g., calcium and magnesium) was also below the detection limit.

[0172] In FIG. 13, the peak at 464 cm.sup.−1 is the bending vibration absorption peak of the Si—O—Si bond, the peak at 1107 cm.sup.−1 is the absorption vibration peak of the Si—O bond, the peak at 3450 cm.sup.−1 is the hydroxyl absorption peak. In curves 2 and 3, an O—P—O antisymmetric stretching peak appears at 977 cm.sup.−1, the absorption peak at 1330 cm.sup.−1 is broadened, attributable to stretching vibration peaks of P—O bonds and the effect of asymmetric stretching vibration of S═O bond superimposed with an antisymmetric stretching vibration of Si—O—Si bond, this absorption peak is caused by stretching vibration of the P—O groups in the framework of metasilicic acid-phosphoric acid. Whereas in curve 1 (dry metasilicic acid solid powder), these two peaks do not appear. Thus, it is stated that in phosphorylated or sulfonated/phosphorylated metasilicic acid particles, phosphate and sulfonate groups are covalently attached to the metasilicic acid molecule.

[0173] In addition, the solid acid catalyst of the present invention can also be used in catalytic cracking reactions and alkylation reactions (of olefins and paraffins) in the oil refinery field. For example, the catalyst is used in the reaction of 2-butene and isobutane to obtain 2, 2, 3-trimethylpentane.

Example 22 (Application Example)

[0174] 0.5 kg of silicon-based sulfonic acid catalyst (from Example 1), 5 kg of 2-butene and 35 kg of isobutane were added to a high pressure reactor, sealed, maintaining reaction pressure of 1 MPa, reaction temperature of 100° C., and reacted for 4 hours, which showed 84% conversion of 2-butene and 98% selectivity to target product 2, 2, 3-trimethylpentane (alkylated gasoline, C8 product) having high octane number with RON value of 98.

[0175] The Example 22 demonstrates that solid acid catalyst can be ideally used in alkylation reactions in oil refinery field.

[0176] As comparison, above process was repeated except that 0.65 kg of silicon-based phosphoric acid catalyst (from Example 20) was used instead of 0.5 kg of silicon-based sulfonic acid catalyst (from Example 1). The conversion of 2-butene was 81%, and selectivity to target product was 93%.

[0177] Also, as comparison, above process was repeated except that 0.6 kg of silicon-based sulfonic acid/phosphoric acid catalyst (from Example 21) was used instead of 0.5 kg of silicon-based sulfonic acid catalyst (from Example 1). The conversion of 2-butene was 82%, and selectivity to target product was 95%.

[0178] The above results illustrate that more amounts of silicon-based phosphoric acid catalyst and silicon-based sulfonic/phosphoric acid catalyst need to be used to achieve conversion and yield close to that of silicon-based sulfonic acid catalyst when used in reactions requiring strong acid as catalyst.

Example 23 (Application Example)

[0179] Silicon-Based Phosphoric Acid Catalyst for Preparation of β-Enaminone.

[0180] A mixture of acetylacetone (100.11 mg, 1.0 mmol) and cyclohexylamine (92.19 mg, 1.0 mmol) was added to a 500 ml flask to mix, the silicon-based phosphoric acid catalyst of Example 20 (1.2 mg) was added, the mixture was heated with a 50° C. oil bath, while stirring the mixture. The starting material had disappeared by TLC detection, the reaction was stopped, the mixture was diluted by adding 150 ml of dichloromethane in the reaction mixture, filtered and the solids were washed with dichloromethane. The filtrate was subjected to distillation under reduced pressure to remove the solvent. The residue was purified by chromatography column (3:1 petroleum ether/ethyl acetate) to obtain yellow oily liquid and the desired product was 4-cyclohexylamino-pent-3-en-2-one in 96% yield.

[0181] .sup.1H NMR (400 MHz, CDCl.sub.3) δ: 10.98 (br s, 1H, NH), 4.90 (s, 1H, CH), 3.36 (t, J=4.5 Hz, 1H, CH), 1.98 (s, 3H, CH.sub.3), 1.93 (s, 3H, CH.sub.3), 1.73-1.87 (m, 4H, CH.sub.2), 1.21-1.38 (m, 6H, CH.sub.2); .sup.13C NMR (100 MHz, CDCl.sub.3) δ: 194.4 (C═O), 161.8 (C), 94.9 (CH), 51.5 (CH), 33.8 (CH.sub.2), 28.7 (CH.sub.2), 25.3 (CH.sub.2), 24.4 (CH.sub.3), 18.6 (CH.sub.3). MS(ESI)(m/z): 182.3 ([M+H].sup.+).

[0182] As comparison, above process was repeated except that equal amount of silicon-based sulfonic acid catalyst (from Example 1) was used. The yield of target product was 92%. This illustrates that silicon-based phosphoric acid is more suitable than silicon-based sulfonic acid for preparation of β-enaminone.

[0183] Analysis and Characterization

[0184] 1. Analysis of the Solid Silicon-Based Sulfonic Acid Catalyst Particles of Example 1:

[0185] During drying of the metasilicic acid gel of Example 1, controlling drying temperature and drying time, moisture from the metasilicic acid particles was previously sufficiently removed, baking was then performed to prevent particle cracking during baking, thereby facilitating maintenance of the structure and shape of the catalyst particles after baking. The substrate of the catalyst particles after baking (i.e., silicon-based sulfonic acid) is a silica substrate in amorphous form or in the form of an amorphous-ordered structure mixture.

[0186] The FT-IR diagram of metasilicic acid and inorganic solid silicon-based sulfonic acid catalytic material of Example 1 (catalyst for short) was shown in FIG. 1.

[0187] As can be seen from FIG. 1, after metasilicic acid has been sulfonated, new infrared characteristic absorption peak appears at 1394 cm.sup.−1, attributed to stretching vibration of O═S═O. In addition, intensity of infrared characteristic signal peak at 1101 cm.sup.−1 is also significantly increased due to infrared characteristic absorption peak of O—S—O in sulfonic acid group coinciding with asymmetric stretching vibration signal peak of Si—O—Si of catalyst framework main body.

[0188] The N.sub.2 adsorption-desorption diagram (A) and pore size distribution diagram (B) of metasilicic acid and inorganic solid silicon-based sulfonic acid catalytic material of Example 1 are shown in FIG. 2.

[0189] As can be seen from FIG. 2 (A), according to IUPAC classification, N.sub.2 adsorption-desorption isotherms of both metasilicic acid and inorganic solid silicon-based sulfonic acid catalytic material exhibits typical Langmuir type IV isothermal adsorption lines and presence of distinct hysteresis loops of type H1, which are typical characteristics of mesoporous materials. Furthermore, specific surface area and pore structure of metasilicic acid remains substantially unchanged after sulfonation.

[0190] Infrared spectra of pyridine adsorption of metasilicic acid and inorganic solid silicon-based sulfonic acid catalytic material of Example 1 are shown in FIG. 3.

[0191] As can be seen from FIG. 3, the metasilicic acid sample exhibits no distinct infrared absorption peaks in the wavelength range of 1400 to 1640 cm.sup.−1. After sulfonation, the inorganic solid silicon-based sulfonic acid catalytic material exhibits four distinct infrared characteristic absorption peaks in the wavelength range of 1400-1640 cm.sup.−1. Wherein the infrared absorption peaks at 1454 cm.sup.−1 and 1622 cm.sup.−1 are the characteristic absorption peaks of pyridine absorbed on Lewis acid centers; the infrared absorption peak at 1546 cm.sup.−1 is the characteristic absorption peak of pyridine absorbed on the Bronsted acid center, mainly provided by the —SO.sub.3H group; the infrared absorption peak at 1491 cm.sup.−1 is the characteristic absorption peak resulted from the co-action of pyridines absorbed on both Lewis acid and Bronsted acid centers.

[0192] The NH.sub.3˜TPD spectra of metasilicic acid and inorganic solid silicon-based sulfonic acid catalytic material of Example 1 was shown in FIG. 4.

[0193] As can be seen from FIG. 4, TPD curve of inorganic solid silicon-based sulfonic acid catalytic material obtained after sulfonation of metasilicic acid shows three distinct NH.sub.3 desorption peaks in range of 50-200° C., 200-400° C. and 400-800° C., corresponding to desorption peaks of NH.sub.3 absorbed on weakly acidic sites, moderately strongly acidic sites and strongly acidic sites on its surface, respectively, whereas only small number of weakly acidic sites are present on the surface of metasilicic acid.

[0194] The thermogravimetric diagram of metasilicic acid and inorganic solid silicon-based sulfonic acid catalytic material of Example 1 was shown in FIG. 5.

[0195] As can be seen in FIG. 5, metasilicic acid shows significant weight loss peak only before 100° C., which is due to desorption of physisorbed water from metasilicic acid surface. After sulfonation of metasilicic acid, there is no significant thermal weight loss, indicating good thermal stability of inorganic solid silicon-based sulfonic acid catalytic material prepared.

[0196] As can be seen from the very perfect peaks in FIG. 2, by crystallization of orthosilicic acid gel, the metasilicic acid gel or crystal with improved crystalline structure and pore structure and significantly increased specific surface area are obtained. The metasilicic acid gel or crystal before and after drying as well as the final silicon-based sulfonic acid particles are all mesoporous materials. There is no noticeable difference in structural characteristics of these mesoporous materials, and their pore volume is approximately 0.9 cm.sup.2/g and pore size is approximately 0.87 nm.

[0197] In particular, all of these mesoporous materials are resistant to corrosion by strong acids.

[0198] The XRD pattern of the sample was obtained using an X-ray powder diffraction spectroscopy instrument of model D/Max-2550 VB+18 KW of Japan Rigaku. The XRD pattern of the dried and unbaked solid metasilicic acid powder as well as the dried and unbaked solid silicon-based sulfonic acid powder was shown in FIG. 7. The XRD pattern of the dried and baked solid metasilicic acid powder as well as the dried and baked solid silicon-based sulfonic acid powder was shown in FIG. 8. The peak at 22° of 2θAngle represents the characteristic diffraction peaks of metasilicic acid and silicon-sulfonic acid. As can be seen from FIG. 8, the diffraction peaks become visibly smooth after baking, indicating that the strength of the solid acid has increased significantly after the solid acid has been baked, it is also illustrated that the crystallinity of the solid acid after baking is significantly increased, which belongs to silica crystals in amorphous form or short-range ordered arrangement-amorphous mixed form. The substrate of solid acid after baking is not silica gel. In addition, metasilicic acid is sulfonated, the intensity and crystallinity of its diffraction peaks do not substantially change, indicating that the crystalline structure of metasilicic acid is not destroyed during sulfonation.

[0199] The particle size distributions of metasilicic acid and silicon-based sulfonic acid obtained in Example 1 were determined by using Malvern laser particle sizer as shown in FIGS. 9 and 10. The average particle sizes of both metasilicic acid particles and silicon-based sulfonic acid particles were approximately 95 μm, illustrating that sulfonation reaction did not change size of metasilicic acid particles.

[0200] A scanning electron microscopy (SEM) picture of baked inorganic solid silicon-based sulfonic acid particle product of Example 1 was shown in FIG. 11. Wherein silica is commercially available control sample. As can be seen from the SEM picture, average particle size of particles is about 90 μm with better crush strength.

[0201] Elemental analysis was performed for catalysts of the examples, wherein content of alkali metals (e.g., sodium and potassium) is below detection limit (below 3 ppm) and content of alkaline earth metals (e.g., calcium and magnesium) is below detection limit.

[0202] 2. FT-IR Analysis of the Silicon-Based Sulfonic Acid Particles of Example 2:

[0203] The FT-IR spectra of metasilicic acid and baked inorganic solid silicon-based sulfonic acid particles in Example 2 are shown in FIG. 12.

[0204] The symmetric stretching vibration absorption peak of S═O bonds is at 1394 cm.sup.−1. Flexural vibration absorption peak of Si—O bonds is at 476 cm.sup.−1. Symmetrical stretching vibration absorption peak of Si—O—Si bonds is at 800 cm.sup.−1. Absorption peak at 965 cm.sup.−1 is weak flexural vibration absorption peak of Si—OH bonds (silica does not have this peak). Absorption peak at 1091 cm.sup.−1 is broadened, which can be attributable to the effect of an asymmetric stretching vibration of the S═O bond superimposed with an antisymmetric stretching vibration of the Si—O—Si bond. The absorption peak at 3421 cm.sup.−1 is the infrared absorption peak of surface hydroxyl groups. The commercial silica sample has a very weak HO peak, indicating that it adsorbed traces of water from air during storage.

Comparative Example 3

[0205] Example I of U.S. Pat. No. 3,929,972 was repeated, except that resulting intermediate product (i.e., particles in form of “sol-gel” soft skin-“sodium metasilicate” hard core) was further dried and baked. The particle size of sodium metasilicate was not disclosed in Example I of the US patent.

[0206] 1 kg of hard sodium metasilicate pentahydrate (glassy) was crushed and milled. The milling operation appeared very difficult. The resulting granules were divided into two batches, the two batches of granules were sieved with two sieves having mesh sizes of 220 μm and 300 μm, respectively, so as to obtain fine particles of sodium silicate pentahydrate (M1) having a mean particle size of larger than 350 μm and coarse particles of sodium silicate pentahydrate (M2) having a mean particle size of larger than 440 μm, respectively. Weighing 60 g of fine particle raw material and 60 g of coarse particle raw material from fine particles of sodium silicate pentahydrate (M1) and coarse particles of sodium silicate pentahydrate (M2), respectively, then repeating the operations in Example I of U.S. Pat. No. 3,929,972, the sulfonation reaction was carried out at 100° C. using concentrated sulfuric acid (98 wt %) at a molar ratio of sodium metasilicate to sulfuric acid of 1:4. After about 25 minutes of sulfonation, the reaction mixture became a viscous mud that was increasingly difficult to stir, so again added concentrated sulfuric acid at a molar ratio of sodium metasilicate to sulfuric acid of 1:2, the sulfonation reaction was allowed to proceed for 5 hours. The sulfonation reaction mixture (i.e. the granular mixture) was filtered with a sand filter, the filter cake was washed with deionized water until the filtrate was neutral. The obtained white solid powder (wet solid) was dried under vacuum at 110° C. for 5 h, dry inorganic solid silicon-based sulfonic acid powder was obtained. Additional 2 mol of sulfuric acid per mol of sodium metasilicate was then added to the resulting dry powder in order to react further, the resulting reaction mixture was filtered with a sand filter and the filter cake was washed with deionized water until the filtrate was neutral, so as to obtain white granular compounds (T1) and (T2) from fine raw material (M1) and coarse raw material (M2), respectively.

[0207] These compounds (T1) and (T2) looked like the mud, the average particle size of compounds (T1) and (T2) was about 27 μm, and about 45 μm, respectively. Since the particle size of the sulfonated compound particles became significantly smaller, illustrating that the sulfonated compound particles formed were not acid resistant, sulfuric acid gradually corroded (i.e. dissolved) the sodium metasilicate particles, the formed silicon-sulfonic acid molecules were detached from the particles into the sulfuric acid solution (liquid phase). Granular compound (T1) or (T2) was rubbed in the palm of the hand, it was felt to be soft with no sandy touch. Clearly, silicon-sulfonic acid molecules were present on the surface of the particulate compound (T1) or (T2) and the structure of the particle (T1) or (T2) was a hard core-soft skin structure, wherein the hard core was sodium metasilicate as the substrate portion of the particle (T1) or (T2) and the soft skin was a relatively soft sol-gel mixture composed of metasilicic acid and silicon-sulfonic acid.

[0208] Weighing a sample of 3 g from granular compound (T1), adding into a flask equipped with a stirrer, 20 ml of concentrated sulfuric acid was then added therein and heated to 90° C. with stirring for the sulfonation reaction. As the sulfonation reaction proceeded, the sodium metasilicate hard core gradually became smaller, eventually both the soft skin and the hard core disappeared, and they were broken down by the sulfuric acid into monomolecular silicon-sulfonic acid compounds and tiny particulate silicon-sulfonic acid compounds of nanoscale size.

[0209] For comparison, particulate compounds (T1) and (T2) were dried under vacuum at 110° C. for 5 h to obtain dried inorganic solid silicon-sulfonic acid powders (T1A) and (T2A), respectively. Then, dried sulfonated solid powder was baked under nitrogen atmosphere for 3 h at 200° C. to obtain baked powdery silicon-sulfonic acid particles (T1B) and (T2B).

TABLE-US-00002 T1A T2A T1B T2B (unbaked) (unbaked) (baked) (baked) Mean particle size, μm 27 45 27 45 BET specific surface 87.5 85.6 89.4 86.9 area, m.sup.2/g Crush strength (N) Brittle Brittle 55 58 Acid amount, mmol/g Unmeasured Unmeasured 0.465 0.425

[0210] The particle size distribution of powdery silicon-sulfonic acid particles (T2B) was measured and results are shown in FIG. 14. As can be seen in FIG. 14, particle size distribution is very broad.

[0211] XRD spectroscopy was performed for samples of silicon-sulfonic acid powders (T1A) and (T2A) and silicon-sulfonic acid particles (T1B) and (T2B) and results are shown in FIG. 15. As can be seen from FIG. 15, crystalline structure of silicon-sulfonic acid particles (T1B) and (T2B) was amorphous with low crystallinity and low intensity.

[0212] The substrate of sodium metasilicate inside baked particle (T1B or T2B) is alkaline compound and therefore, particles (T1B or T2B) are not acid resistant. When baked particles (T1B or T2B) are used as catalyst in acidic reaction system, which will gradually decompose.

[0213] In addition, the above fine particles of sodium silicate pentahydrate (M1) were used, repeating the above preparation process, except that the temperature of the sulfonation reaction is 80° C., 90° C., 110° C. and 120° C., respectively, the acid amounts of the resulting baked silicon-sulfonic acid particulate product were 0.378, 0.402, 0.398 and 0.385 mmol/g, respectively, illustrating that in Example I of U.S. Pat. No. 3,929,972, the optimal sulfonation reaction temperature was approximately 100° C. The acid amounts of the finally obtained particles (T1B) and (T2B) were very low due to detachment of the silicon-sulfonic acid molecules from the sodium metasilicate particles in the sulfonation reaction.

[0214] In addition, it is shown according to our experimental results that when Example I of US Patent was repeated using anhydrous sodium metasilicate or sodium metasilicate nonahydrate feedstock instead of sodium metasilicate pentahydrate feedstock, various results obtained were nearly identical to above results.

[0215] In addition, as can be seen from claims of US patent, the aim of US patent is to provide monomolecular compound SiO (HSO.sub.4).sub.2 and fine particulate compound of nanoscale size instead of silicon-sulfonic acid particles or powder.

Comparative Example 4

[0216] Silica gel sulfonic acid catalytic materials were prepared using silica gel (silica) direct sulfonation method.

[0217] Took 200 mL ethyl orthosilicate, 200 mL isopropyl alcohol, 200 mL water, adjusted pH of resulting mixture to 3 with concentrated nitric acid, and 200 mL water was added; the mixture was slowly heated with stirring to 80° C., and then hydrolyzed to pale green gel for 3 h; after aging for 24 h, the mixture is dried at the temperature of 110° C. for 24 h and milled to form silica gel of 90 μm.

[0218] 5 g of silica gel of 90 μm size was added to 25 mL of chlorosulfonic acid for direct sulfonation, stirred, and sulfonated at 130° C. for 6 h; then, the resulting mixture was cooled to room temperature, filtered, but not washed with deionized water until the filtrate was neutral. The resulting white solid powder was dried under vacuum at 110° C. for 5 h, and finally, inorganic solid silica gel sulfonic acid catalytic material was obtained, the acid amount thereof was measured to be 31.653 mmol/g.

[0219] The resulting solid sample after sulfonation was washed with deionized water until the filtrate was neutral, the resulting white solid powder was then dried under vacuum at 110° C. for 5 h, finally, inorganic solid silica gel sulfonic acid catalytic material was obtained with a measured acid amount of only 0.128 mmol/g. This indicates that the silica gel has a strong adsorption to chlorosulfonic acid. If the sulfonated particles were not washed with deionized water, much chlorosulfonic acid would be adsorbed on the surface of the silica gel, resulting in a large increase in the measured acid amount.