CN108273551A - A kind of solid-carrying type Performance of Isomerization Catalysts for Light n-Paraffin and its preparation and application - Google Patents

Abstract

The invention provides a solid-supported light alkane isomerization catalyst and its preparation and application. The catalyst is prepared by polymerizing Bronsted acid-type ionic liquid monomers with olefin groups to form polymer intermediates, and then reacting with Lewis acid _AlCl3 in a solvent. The solid-supported catalyst is prepared by polymerization instead of the traditional impregnation method or chemical grafting method, so there are more active components, more stable combination and longer service life. The immobilized ionic liquid catalyst prepared by the method provided by the invention has Bronsted acid and Lewis acid double acidity, and compared with the non-immobilized ionic liquid catalyst, it saves the amount of ionic liquid, is more convenient to separate, and is easier to operate. Simple. In addition, the preparation cost of the immobilized ionic liquid catalyst is low, and has good industrial application prospect.

Description

A solid-supported light alkane isomerization catalyst and its preparation and application

technical field

The invention provides a solid-supported light alkane isomerization catalyst and its preparation and application, which belong to the field of petrochemical industry.

Background technique

At present, under the influence of environmental protection and automobile technology progress, people's requirements for gasoline quality are getting higher and higher. In my country's motor gasoline, catalytic cracking (FCC) gasoline accounts for about 70%, and its high olefin and sulfur content is the bottleneck restricting the production of clean gasoline in my country. It is not difficult to use hydrogenation technology to achieve deep desulfurization of gasoline and reduce the olefin content in FCC gasoline. However, since olefins are also components of high-octane gasoline, a large reduction in its content will lead to a serious loss of gasoline octane, thus Affect gasoline vehicle performance and refinery economics. In addition, aromatics in gasoline, especially benzene, are more toxic. In this case, it is imperative to develop clean gasoline blending components with no sulfur, low (no) olefins, low (no) aromatics and high octane number. The processes for producing high-octane gasoline and its components include catalytic reforming, etherification, alkylation and isomerization. Among them, the product of C5/C6 isomerization technology does not contain sulfur, olefins and aromatics, and is an ideal clean gasoline blending component. The isomerization of light alkanes can increase the front-end octane number of gasoline, make the distillation range and octane number of gasoline have a reasonable distribution, and thus improve the starting performance of the engine.

In the current literature and patents, the metal-acid center dual-functional catalysts used in C5/C6 isomerization technology are mainly used, that is, under hydrogenation conditions, metals provide hydrogenation and dehydrogenation active centers to complete hydrogenation and dehydrogenation In the process, the carrier provides the acidic center to complete the isomerization process of the carbon chain. The metals include noble metals Pt/Pd (CN 106669805A) or non-noble metals Ni, Co, W, Mo (CN 104289251A). Acidic carriers include molecular sieves (CN 106732752A), solid superacids (CN1541764A), heteropolyacids (CN 1465436A) and the like. The bifunctional isomerization catalyst can be divided into three types according to the operating temperature. The first type: high temperature type, the reaction temperature is ≥320°C (Applied Catalysis A: General, 495 (2015) 173-183, Journal of Catalysis 303 (2013 ) 50-59 , Catalysis Today 172 (2011) 2-7); the second type: medium temperature type, 200℃<reaction temperature<320℃(Journal of American Chemistry Society, 137(2015) 10231-10237, Industrial & Engineering Chemistry Research 50 (2011) 9918-9924, Catalysis Today 49 (1999) 293-302); the third type: low temperature type, reaction temperature ≤ 200 ℃ (Applied Catalysis A: General 483 (2014) 103-109, Journal of Catalysis 319 (2014) 283-296, Applied Catalysis A: General, 429-430 (2012) 1-8). However, most bifunctional catalysts are prone to carbon deposition, the reaction temperature is high, the cost is high, and they need to be operated under a hydrogen atmosphere, which increases the difficulty and cost of operation. Moreover, the isomerization reaction is an exothermic reaction, and a lower reaction temperature is more favorable thermodynamically. Therefore, lowering the isomerization reaction temperature is the development trend of alkane isomerization catalysts.

Ionic liquids, also known as room temperature ionic liquids, refer to organic molten salts that are liquid at room temperature or slightly higher than room temperature, and are composed of asymmetric organic cations and organic or inorganic anions. Ionic liquids have the advantages of low volatility, good thermal stability, strong solubility, adjustable acidity, and designable anions and cations, so they have attracted widespread attention.

In prior art literature, light alkane isomerization ionic liquid catalysts are mainly chloroaluminate-type ionic liquid catalysts and modified ionic liquid catalysts.

US 2003/0109767 A1 discloses a method for isomerizing C5-C8 alkanes, the ionic liquid catalysts are quaternary ammonium chloroaluminate ionic liquid, imidazole chloroaluminate ionic liquid, pyridine chloroaluminate ionic liquid.

CN 103934023 A discloses a method for the isomerization of C5/C6 alkanes. The ionic liquid catalyst is a dicationic chloroaluminate ionic liquid. It is pointed out that the introduction of dications increases the acidic sites in the structure of the ionic liquid and obtains a relatively High acid density reduces the dosage of ionic liquid. In a nitrogen atmosphere of 0.5 MPa, when AlCl ₃ is 0.4 mol, the molar ratio of ionic liquid precursor to AlCl ₃ is 1:4, the mass ratio of catalyst to n-hexane is 1:1, the rotation speed is 600 rpm, the reaction time is 4h, and the reaction temperature At 100 ^o C, the conversion rate of n-hexane was 79.2wt%, the yield of isomerized oil was 66.1wt%, and the selectivity of isoparaffin was 84.3wt%. Its disadvantage is that the selectivity of hexane isomers is not high.

Industrial & Engineering Chemistry Research, 47 (2008) 8205-8210 explored the effect of reaction conditions on the isomerization of n-pentane catalyzed by ionic liquid Et ₃ NHCl-2AlCl ₃ . The conversion rate of n-pentane increases with the increase of reaction temperature or reaction time or the volume ratio of agent to oil, while the change law of the yield of isomerized oil and the selectivity of isoparaffin is opposite to this. When the molar ratio of ionic liquid precursor Et ₃ NHCl to AlCl ₃ is 1:2, the optimum reaction temperature is 30°C, the reaction time is 3 h, the volume ratio of solvent to oil is 1:1, the conversion rate of n-pentane is 44.61wt%, and the iso The yield of structured oil was 96.07wt%, and the selectivity of isoparaffin was 90.52wt%. The disadvantage is that the conversion rate of n-pentane is low and the amount of ionic liquid catalyst is large.

Journal of Fuel Chemistry and Technology, 36 (2008) 306-310 explored several initiators (n-butanol, isobutene, isobutane and isopentane) on ionic liquid Et ₃ NHCl-2AlCl ₃ catalyzed n-hexane isomerization influences. It was found that isobutene did not promote the reaction as an initiator; the effect of isobutane as an initiator was poor; when n-butanol was used as an initiator, the conversion rate of n-hexane was higher, but the liquid yield was low; isopentane was used as an initiator When , the n-hexane conversion rate, isoparaffin selectivity and liquid yield are all good. When the amount of initiator isopentane is 30%, the reaction temperature is 50°C, the reaction time is 45 min, and the volume ratio of solvent to oil is 1:1, the conversion rate of n-hexane is 84.54wt%, and the yield of isohexane is 26.5wt%. Its disadvantages are: firstly, it is necessary to add an initiator, and the addition of initiator isopentane makes the raw material of the reaction become the isomerization of non-normal alkanes; secondly, the selectivity of hexane isomers is not high.

Theoretical Foundations of Chemical Engineering, 47 (2013), 66-70 explored the effect of reaction conditions on the isomerization of n-hexane catalyzed by ionic liquid BmimCl-2AlCl ₃ . The reaction rule is similar to the isomerization of n-pentane catalyzed by Et ₃ NHCl-2AlCl ₃ above. When the molar ratio of ionic liquid precursor BmimCl to _AlCl3 is 1:2, the optimal reaction temperature is 30°C, the reaction time is 4 h, the volume ratio of solvent to oil is 1:1, the conversion rate of n-hexane is 60wt%, and the yield of isohexane is 22.1 wt%. The disadvantage is that the amount of ionic liquid catalyst is large and the conversion rate of n-hexane is not high.

From the current point of view, non-solid-supported ionic liquid catalysts have good effects in catalyzing the isomerization of light alkanes, but there are many shortcomings. First, the amount of ionic liquid catalyst is relatively large, and the price of ionic liquid is relatively high, and the cost is high; second, continuous reaction cannot be carried out; third, the separation of product and catalyst is inconvenient; fourth, the selectivity of target isoparaffins is not high.

CN 103373886 A discloses a solid-supported ionic liquid catalyst, in which the solid-supported ionic liquid catalyst is prepared by impregnating the ionic liquid BmimCl-2AlCl ₃ onto the carrier Al ₂ O ₃ , and catalyzes the isotropy of n-pentane in a fixed-bed reactor. structuring reaction. When 10% isopentane and 90% n-pentane are used as reaction materials, at a temperature of 250°C, a system pressure of 0.5 MPa, a mass space velocity of 0.5 h ^-1 , and a molar ratio of hydrogen to n-pentane of 0.5, the normal Pentane conversion reached 35%. Its disadvantages are: first, the traditional impregnation method has limited loading capacity, weak combination, and easy loss of active components; second, the reaction temperature is high and the catalyst activity is not high.

Contents of the invention

The purpose of the present invention is to solve the problem that the ionic liquid catalyst used for alkane isomerization in the prior art has a large amount of catalyst, cannot carry out continuous reaction, and the selectivity of the target isomer is not high, and provides a solid-supported Type light alkane isomerization catalyst and its preparation and application. The catalyst prepared by the invention has the advantages of less dosage, high catalytic activity and stable performance.

The purpose of the present invention can be achieved through the following technical solutions:

A solid-supported light alkane isomerization catalyst: a polymer intermediate is formed by polymerizing a Bronsted acid-type ionic liquid monomer with an olefin group, and then the polymer intermediate is reacted with _AlCl in a solvent. The obtained solid-supported ionic liquid catalyst.

Its chemical structural formula of described polymer intermediate is:

;

Wherein, W is any one of imidazole ring, pyridine ring base nitrogen heterocycle quaternary ammonium salt; M is any one of phenyl or methylene, ethylene, propylene; a is 3 or 4, n is 3-100; X is any one of Cl, Br and I.

A method for preparing a solid-supported light alkane isomerization catalyst as described above, comprising the steps of:

(1) Preparation of polymer intermediates: Add the Bronsted acid type ionic liquid monomer with olefin group into solvent A, stir to make it evenly mixed, then add alkyl sultone, stir well until the reaction is complete, Washing and vacuum drying to obtain white solid B; secondly, dissolving white solid B in solvent A, adding a polymerizing agent azobisisobutyronitrile, the polymerization reaction is complete, washing and vacuum drying to obtain white solid C; finally, white solid C is reacted with inorganic acid and dried in vacuum to obtain the polymer intermediate;

(2) Preparation of the catalyst: under nitrogen protection, in the solvent D, mix the polymer intermediate and AlCl ₃ uniformly in a three-necked flask, stir until the reaction is complete, remove the solvent D, and obtain the immobilized light Alkane isomerization catalyst.

The solvent A described in step (1) includes one of ethanol, acetone, and ethyl acetate, and the molar ratio of the Bronsted acid-type ionic liquid monomer with an alkene group to the alkyl sultone is 1:5 ~5:1.

In the step (1), the polymerization reaction temperature is 0-100° C., and the reaction time is 1-48 h.

The solvent D described in step (2) includes one of dichloromethane and n-heptane.

In step (2), the molar ratio of AlCl ₃ to the polymer intermediate is 0.1-10, the reaction temperature is 20-140°C, and the reaction time is 1-12 h.

The application of a solid-supported light alkane isomerization catalyst as described above in catalyzing the isomerization of light alkane comprises the following steps:

(1) Load the solid-supported light alkane isomerization catalyst into a fixed-bed reactor, and the reaction material is C5-C8 light alkane;

(2) The reaction temperature is 20-200°C, the reaction space velocity is 0.1-20 h ^-1 , the system pressure is 0.1-10 MPa, and the molar ratio of gas to C5-C8 light alkanes is 0.1-10.

The beneficial effects of the present invention are:

A kind of light alkane isomerization catalyst that is used for fixed-bed reactor described in the present invention is to form the polymer intermediate by polymerizing the Bronsted acid type ionic liquid monomer with alkene group, then in solvent and Lewis Acid AlCl ₃ reaction preparation. The solid-supported catalyst is prepared by polymerization instead of the traditional impregnation method or chemical grafting method, and has more active components and more stable combination. The prepared solid-supported catalyst has Bronsted acid and Lewis acid double acidity, and is used in a fixed-bed reactor, which can save the amount of ionic liquid, has high catalyst activity, higher selectivity for target isoparaffins, and stable catalyst; and does not require Adding metals or precious metals is more cost-effective than dual-function catalysts, and the operating temperature is lower.

Description of drawings

Fig. 1 is the infrared spectrogram of the solid-supported ionic liquid catalyst polymer intermediate (poly-VMPS-Cl) of the present invention.

Detailed ways

The implementation process and beneficial effects of the present invention are described in detail below through specific examples, which are intended to help better understand the essence and characteristics of the present invention, and are not intended to limit the scope of implementation of this case.

Example 1

A kind of preparation of solid-supported light alkane isomerization catalyst comprises the steps:

(1) Accurately weigh 9.18 g of 1-vinylimidazole in a 150 mL three-necked flask, add 30 mL of ethyl acetate, stir to mix evenly, then add 12.2 g of 1,3-propyl sultone, and place in an ice bath Reflux for 12 h, then wash three times with ethyl acetate, and vacuum dry at 50°C for 4 h to obtain white solid VMPS; then, accurately weigh 12.5 g VMPS and dissolve it in 20 mL of methanol, add 0.05 g of polymerizing agent azobisisobutyl Nitrile (AIBN), reflux reaction at 60°C for 24 h under the protection of nitrogen, washed with ethanol three times and vacuum-dried at 80°C for 4 h to obtain poly-VMPS as a white solid; finally, accurately weigh 10.81 g of poly-VMPS and dissolve it in 20 mL of methanol 5.48 g hydrochloric acid solution (36.5 wt%) was added dropwise, reacted at room temperature for 10 h, rotary evaporated and vacuum dried at 90 °C for 6 h to obtain poly-VMPS-Cl, which is the polymer intermediate;

(2) Accurately weigh 5.06 g of the polymer intermediate poly-VMPS-Cl into a 150 mL three-necked bottle, add 20 mL of n-heptane, and add 5.33 g of dried AlCl ₃ in batches under a protective atmosphere, After stirring evenly, raise the temperature of the system to 120°C for reflux reaction for 5 hours, filter and vacuum dry at 100°C for 6 hours to obtain the immobilized ionic liquid catalyst A.

Example 2

A kind of preparation of solid-supported light alkane isomerization catalyst comprises the steps:

(1) Accurately weigh 9.18 g of 1-vinylimidazole in a 150 mL three-necked flask, add 30 mL of ethyl acetate, stir to mix evenly, then add 12.2 g of 1,3-propyl sultone, and place in an ice bath Reflux for 12 h, wash with ethyl acetate three times, and vacuum dry at 50°C for 4 h to obtain white solid VMPS; then, accurately weigh 12.5 g of VMPS and dissolve in 20 mL of methanol, add 0.5 g of polymerizing agent azobisisobutyl Nitrile (AIBN), reflux reaction at 60°C for 24 h under the protection of nitrogen, washed with ethanol three times and vacuum-dried at 80°C for 4 h to obtain poly-VMPS as a white solid; finally, accurately weigh 10.81 g of poly-VMPS and dissolve it in 20 mL of methanol 5.48 g of hydrochloric acid solution (36.5 wt%) was added dropwise, reacted in ice bath for 18 h, rotary evaporated and vacuumed at 90 ° C for 6 h to obtain poly-VMPS-Cl, which is the polymer intermediate;

(2) Accurately weigh 5.06 g of the polymer intermediate poly-VMPS-Cl into a 150 mL three-necked bottle, add 20 mL of n-heptane, and add 4.80 g of dried AlCl ₃ in batches under a protective atmosphere, After stirring evenly, raise the temperature of the system to 120°C for reflux reaction for 5 hours, filter and vacuum dry at 100°C for 6 hours to obtain the immobilized ionic liquid catalyst B.

Application Example 1

The solid-supported light alkane isomerization catalyst prepared in Example 1 is used to catalyze the light alkane isomerization reaction, specifically comprising the following steps:

(1) Load 6 g of solid-supported ionic liquid catalyst A into a fixed-bed reactor, and the reaction material is n-hexane.

(2) The reaction temperature is 150°C, the mass space velocity of the reaction material is 0.5 h ^-1 , the system pressure is 0.6 MPa, and the molar ratio of nitrogen to n-hexane is 0.2.

See the table below for sampling at different times of reaction.

Application Example 2

The solid-supported light alkane isomerization catalyst prepared in Example 2 is used to catalyze the light alkane isomerization reaction, specifically comprising the following steps:

(1) Load 6 g of solid-supported ionic liquid catalyst B into a fixed-bed reactor, and the reaction material is n-hexane.

(2) The reaction temperature is 150°C, the mass space velocity of the reaction material is 0.5 h ^-1 , the system pressure is 0.6 MPa, and the molar ratio of nitrogen to n-hexane is 0.2.

See the table below for sampling at different times of reaction.

Application Example 3

The solid-supported light alkane isomerization catalyst prepared in Example 1 is used to catalyze the light alkane isomerization reaction, specifically comprising the following steps:

(1) Put 6 g of solid-supported ionic liquid catalyst A into a fixed-bed reactor, and the reaction material is n-hexane;

(2) The reaction temperature is 120°C, the mass space velocity of the reaction material is 0.5 h ^-1 , the system pressure is 0.6 MPa, and the molar ratio of nitrogen to n-hexane is 0.2.

See the table below for sampling at different times of reaction.

Application Example 4

The solid-supported light alkane isomerization catalyst prepared in Example 1 is used to catalyze the light alkane isomerization reaction, specifically comprising the following steps:

(1) Put 6 g of solid-supported ionic liquid catalyst A into a fixed-bed reactor, and the reaction material is n-hexane;

(2) The reaction temperature is 180°C, the mass space velocity of the reaction material is 0.5 h ^-1 , the system pressure is 0.6 MPa, and the molar ratio of nitrogen to n-hexane is 0.2.

See the table below for sampling at different times of reaction.

Application Example 5

The solid-supported light alkane isomerization catalyst prepared in Example 1 is used to catalyze the light alkane isomerization reaction, specifically comprising the following steps:

(1) Put 6 g of solid-supported ionic liquid catalyst A into a fixed-bed reactor, and the reaction material is n-hexane;

(2) The reaction temperature is 140°C, the mass space velocity of the reaction material is 1.0 h ^-1 , the system pressure is 0.6 MPa, and the molar ratio of nitrogen to n-hexane is 0.2.

See the table below for sampling at different times of reaction.

Application Example 6

The solid-supported light alkane isomerization catalyst prepared in Example 1 is used to catalyze the light alkane isomerization reaction, specifically comprising the following steps:

(1) Load 6 g of solid-supported ionic liquid catalyst A into a fixed-bed reactor, and the reaction material is n-hexane.

(2) The reaction temperature is 140°C, the mass space velocity of the reaction material is 0.3 h ^-1 , the system pressure is 0.6 MPa, and the molar ratio of nitrogen to n-hexane is 0.2.

See the table below for sampling at different times of reaction.

Application Example 7

The solid-supported light alkane isomerization catalyst prepared in Example 1 is used to catalyze the light alkane isomerization reaction, specifically comprising the following steps:

(1) Load 6 g of solid-supported ionic liquid catalyst A into a fixed-bed reactor, and the reaction material is n-hexane.

(2) The reaction temperature is 160°C, the mass space velocity of the reaction material is 0.5 h ^-1 , the system pressure is 0.6 MPa, and the molar ratio of nitrogen to n-hexane is 0.3.

See the table below for sampling at different times of reaction.

Application Example 8

The solid-supported light alkane isomerization catalyst prepared in Example 1 is used to catalyze the light alkane isomerization reaction, specifically comprising the following steps:

(1) Load 6 g of solid-supported ionic liquid catalyst A into a fixed-bed reactor, and the reaction material is n-hexane.

(2) The reaction temperature is 160°C, the mass space velocity of the reaction material is 0.5 h ^-1 , the system pressure is 0.6 MPa, and the molar ratio of hydrogen to n-hexane is 0.3.

See the table below for sampling at different times of reaction.

In order to prove the technical effect of the technical solution of the present invention, the isomerization reaction product was analyzed with a SHIMADZU GC-2014 gas chromatograph.

The calculation of n-hexane conversion rate X , hexane isomer selectivity S _{i -C6} , dibranched hexane isomer selectivity S _di-C6 is given by the following formula:

.

As can be seen from the data of the examples, the solid-supported ionic liquid catalyst described in the present invention has good catalytic n-hexane isomerization reaction activity, and by adjusting the reaction conditions, isohexane selectivity and double-branched hexane isomers Selectivity is greatly improved.

In Figure 1, near 3436.41 cm ^-1 is the broad asymmetric -OH stretching vibration absorption peak; 3150.36 cm ^-1 , 3099.41 cm ^-1 , 3076.52 cm ^-1 are the stretching vibration absorption peaks of the CH bond on the imidazole ring; 2954.80 cm ^-1 , 2870.02cm ^-1 are the vibration absorption peaks of the CH bond on the alkyl substituent on the imidazole ring; 1651.66 cm ^-1 and 1575.10 cm ^-1 are the stretching vibration absorption peaks of the C=C bond and C=N bond on the imidazole ring respectively; 1457.92 cm ^-1 is the skeleton vibration absorption peak of the imidazole ring; 1206.03 cm ^-1 and 1176.20 cm ^-1 are the asymmetric stretching vibration absorption peaks of the S=O bond on the sulfonic acid group; 1036.95 cm ^-1 is the S= O bond symmetrical stretching vibration absorption peak.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not possible to exhaustively list all the implementation manners here. Obvious changes or changes that are not extended are still within the protection scope of the present invention.

Claims (9)

1. A solid-supported light alkane isomerization catalyst is characterized in that: the Bronsted acid type ionic liquid monomer with alkene group forms a polymer intermediate by polymerization reaction, and then the polymer intermediate is in a solvent A solid-supported ionic liquid catalyst prepared by reacting with _AlCl3 . 2. The solid-supported light alkane isomerization catalyst according to claim 1, characterized in that: the chemical structural formula of the polymer intermediate is: ; Wherein, W is any one of imidazole ring, pyridine ring base nitrogen heterocycle quaternary ammonium salt; M is any one of phenyl or methylene, ethylene, propylene; a is 3 or 4; n is 3-100, and X is any one of Cl, Br and I. 3. a method for preparing the solid-supported light alkane isomerization catalyst as claimed in claim 1 or 2, is characterized in that: comprise the steps: (1) Preparation of polymer intermediates: Add the Bronsted acid type ionic liquid monomer with olefin group into solvent A, stir to make it evenly mixed, then add alkyl sultone, stir well until the reaction is complete, Washing and vacuum drying to obtain white solid B; secondly, dissolving white solid B in solvent A, adding a polymerizing agent azobisisobutyronitrile, the polymerization reaction is complete, washing and vacuum drying to obtain white solid C; finally, white solid C is reacted with inorganic acid and dried in vacuum to obtain the polymer intermediate; (2) Preparation of the catalyst: under nitrogen protection, in the solvent D, mix the polymer intermediate and AlCl ₃ uniformly in a three-necked flask, stir until the reaction is complete, remove the solvent D, and obtain the immobilized light Alkane isomerization catalyst. 4. The method for preparing a solid-supported light alkane isomerization catalyst according to claim 3, characterized in that: the solvent A described in step (1) comprises one of ethanol, acetone, and ethyl acetate, The molar ratio of Bronsted acid type ionic liquid monomer with olefin group to alkyl sultone is 1:5~5:1. 5. the method for preparing solid-supported light alkane isomerization catalyst according to claim 3, is characterized in that: the temperature of described step (1) polymerization reaction is 0～100 ℃, and reaction time is 1～48 h . 6 . The method for preparing a solid-supported light alkane isomerization catalyst according to claim 3 , wherein the solvent D in step (2) includes one of dichloromethane and n-heptane. 7. The method for preparing a solid-supported light alkane isomerization catalyst according to claim 3, characterized in that: in step (2), the molar ratio of _AlCl3 to the polymer intermediate is 0.1 to 10, and the reaction temperature is 20~140℃, the reaction time is 1~12h. 8. An application of the solid-supported light alkane isomerization catalyst as claimed in claim 1 or 2 in catalyzing the isomerization of light alkane. 9. The application according to claim 8, characterized in that: comprising the following steps: (1) Load the solid-supported light alkane isomerization catalyst into a fixed-bed reactor, and the reaction material is C5-C8 light alkane; (2) The reaction temperature is 20-200°C, the reaction space velocity is 0.1-20 h ^-1 , the system pressure is 0.1-10 MPa, and the molar ratio of gas to C5-C8 light alkanes is 0.1-10.