CN106140222A - A kind of bromomethane preparing isobutene catalyst with Ti-Si composite oxide as carrier and preparation method and application - Google Patents

Abstract

The present invention discloses a kind of bromomethane preparing isobutene catalyst with Ti-Si composite oxide as carrier and preparation method and application.The preparation method of described catalyst, comprises the steps: that (1) uses the sol-gal process preparation titanium-silicon composite oxide carrier containing auxiliary agent cerium；(2) zinc oxide is introduced to step (1) resulting vehicle, drying and roasting；(3) catalyst precarsor after introducing zinc oxide carries out bromination process making zinc oxide weight content in catalyst is 0.5%-20%, preferably 1%-15%, further preferred 1%-9%；Zinc bromide weight content is 10%-50%, preferably 15%-45%, further preferred 18%-39%.Catalysis prepared by the method can significantly improve the selectivity of isobutene..

Description

A kind of bromomethane preparing isobutene catalyst with Ti-Si composite oxide as carrier and preparation method and application

Technical field

The present invention relates to the preparation method of a kind of bromomethane preparing isobutene catalyst, relate in particular to the preparation method and applications of a kind of bromomethane height selectivity preparing isobutene catalyst with Ti-Si composite oxide as carrier.

Background technology

Isobutene. is a kind of important basic organic chemical industry raw material, and its derived product is numerous, and vertical industry chain is complicated, and consumption structure is diversified trend.Multiple high value-added product can be prepared for raw material, such as: multiple Organic Chemicals and the fine chemistry products such as butyl rubber, polyisobutylene, methyl tertiary butyl ether(MTBE), isoprene and lucite with isobutene..Owing to the market scale of isobutene. downstream product constantly expands, its imbalance between supply and demand will gradually highlight, and particularly under the background of petroleum resources exhaustion day by day, the yield of isobutene. has become the critical bottleneck of restriction downstream industry development.Therefore, the isobutene. syntheti c route of exploitation Non oil-based route, extremely the most urgent.

Methane is the main component of natural gas, the important research content during therefore methane trans-utilization just becomes gas chemical industry's technology.The most in recent years, under the overall background that shale gas develops, if it is possible to realize producing isobutene. from methane, a new approach will be provided for obtaining isobutene..But methane stable in properties, the most easily-activated, become the bottleneck of methane chemical utilization.The most many researcheres carry out methane activation, Study on Transformation, among these, the technology that methane converts after halogen functional groupization more one after another, are expected to become the important breakthrough mouth solving a methane transformation technology difficult problem.

Can the many chemical products of preparation from halide.Chinese patent CN 101041609A, CN 101284232A disclose one by methane at oxygen and HBr/H₂Being converted into bromomethane under the effect of O, then bromomethane reacts the method generating C3 ~ C13 mixing high-carbon hydrocarbon further, and the hydrocarbon selective of more than C5 is 70%.Wherein, HBr for methane bromination, then discharges in first reactor in second reactor, recovered after be used further in back reaction, it is achieved the recycling of HBr.(CN 102527427A, the Jieli such as Wang Ye He, Ting Xu, Zhihui Wang, et.al. Angew. Chem. Int. Ed. 2012,51,2438-2442) modified molecular sieve catalyst disclosing a kind of halide propylene and preparation method thereof.By using fluorochemical moditied processing molecular sieve, obtaining a kind of containing appropriate microporous structure and the catalyst of acidity, this catalyst can effectively be catalyzed halide and be converted into the reaction of propylene.Prepared catalyst one way bromomethane conversion ratio in the reaction that bromomethane is preparing propylene transformed is 35 ~ 99%, and the selectivity of propylene is 27 ~ 70%；In the reaction that chloromethanes is preparing propylene transformed, one way methyl chloride conversion rate is 30 ~ 99%, and the selectivity of propylene is 15 ~ 70%.Ivan M. Lorkovic et al. (Ivan M. Lorkovic, Aysen Yilmaz, Gurkan A. Yilmaz, et al. Catalysis Today, 2004,98,317-322) it is also proposed that generate bromo-hydrocarbons with bromine with the alkane reaction in natural gas, then on metal oxide catalyst, bromo-hydrocarbons is converted into dimethyl ether, methanol and metal bromide, obtain metal-oxide after metal bromide oxygen recovery and discharge simple substance bromine, completing the circulation of bromine.

It is mainly methanol, dimethyl ether, acetic acid, higher hydrocarbons, ethylene and propylene etc. currently, with respect to purpose product in the existing document that halide converts.In the technology with the low-carbon alkene of relatively high added value as target product, single selectivity of product is the highest, not yet finds the relevant report of bromomethane high selectivity isobutene..

Summary of the invention

For the deficiencies in the prior art, the invention provides a kind of bromomethane height with Ti-Si composite oxide as carrier and selectively produce the preparation method and applications of isobutene catalyst.

The preparation method of above-mentioned bromomethane preparing isobutene catalyst, comprises the steps:

(1) the sol-gal process preparation titanium-silicon composite oxide carrier containing auxiliary agent cerium is used；

(2) zinc oxide is introduced to step (1) resulting vehicle, drying and roasting；

(3) catalyst precarsor after introducing zinc oxide carries out bromination process making zinc oxide weight content in catalyst is 0.5%-20%, preferably 1%-15%, further preferred 1%-9%；Zinc bromide weight content is 10%-50%, preferably 15%-45%, further preferred 18%-39%.

Use the sol-gal process preparation titanium-silicon composite oxide carrier detailed process containing auxiliary agent cerium as follows described in the preparation method step (1) of above-mentioned bromomethane preparing isobutene catalyst: to be dissolved in deionized water with tetraethyl orthosilicate for silicon source, it is stirred at room temperature prehydrolysis certain time, sequentially add the aqueous isopropanol of tetrabutyl titanate, with the aqueous solution containing cerium salt, after being sufficiently mixed, it is warming up to uniform temperature, hydrolyze under stirring condition, gel is formed after certain time, it is down to room temperature ageing again, after drying, roasting, prepares the titanium-silicon composite oxide carrier containing auxiliary agent cerium.With material gauge rate of charge as SiO in above-mentioned system₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.005-0.19:0.002-0.04:0.5-5:10-100, preferably SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.01-0.07:0.005-0.02:1-3:20-50；The above-mentioned tetraethyl orthosilicate prehydrolysis time is 0.2h-4h, preferably 0.5h-2h；During the hydrolysis of above-mentioned tetrabutyl titanate, temperature is 40 DEG C-90 DEG C, and preferably 50 DEG C-80 DEG C, hydrolysis time is 1h-16h, preferably 2h-8h；Above-mentioned gel digestion time is 1h-8h, preferably 2h-4h；Cerium salt described in said method is the inorganic salts, preferably cerous nitrate such as cerous nitrate, cerium chloride, cerous sulfate；Described drying condition is 60 DEG C of-120 DEG C of dry 2h-16h, preferably 80 DEG C-100 DEG C of dry 4h-8h；Described roasting condition is roasting 1h-8h under 300 DEG C of-700 DEG C of air atmospheres, preferably 400 DEG C-600 DEG C roasting 2h-6h, molding, prepares the titanium-silicon composite oxide carrier Han cerium.

Above-mentioned can make or choose suitable particle shape according to the needs used containing cerium titanium-silicon composite oxide carrier, as made bar shaped, sheet shape, cylindricality, spherical etc..Shaping can be carried out by this area general knowledge.

Described in the preparation method step (2) of above-mentioned bromomethane preparing isobutene catalyst, zinc oxide is introduced to the method that the method for rear silica supports is well known to those skilled in the art, as impregnation method can be used to introduce.Concrete grammar is as follows: the carrier using zinc solution impregnation steps (1) to obtain, and obtains bromomethane preparing isobutene catalyst precarsor after drying, roasting.Described drying condition is, temperature 60 C-150 DEG C, preferably 80 DEG C-120 DEG C；Time is 1h-24h, preferably 4h-8h；Can be vacuum drying time dry, it is also possible to for being dried under the conditions of inert gas shielding, it is also possible to be dried in air atmosphere.Described roasting condition is, temperature 300 DEG C-600 DEG C, preferably 400 DEG C-500 DEG C；Time is 1h-24h, preferably 4h-8h；It can be roasting under the conditions of inert gas shielding during roasting, it is also possible to roasting in air atmosphere.

In said method, zinc salt can be inorganic salt, it is also possible to for one or more in organic salt, preferably nitrate, hydrochlorate, acetate, citrate.

Bromination described in the preparation method step (3) of above-mentioned bromomethane preparing isobutene catalyst processes, and refers to use gas phase bromine-containing compound to process the sample of load zinc oxide.Bromine-containing compound refers to one or more in bromomethane, methylene bromide, bromoform, preferably bromomethane.Gas phase bromine-containing compound can also be used to carry out bromination process with the mixed gas of noble gas, and when using mixed gas bromination to process, bromomethane volumetric concentration is not less than 20%, preferably not less than 30%.Concrete bromination process is as follows: be placed in continuous fixed bed reactor by the sample of load zinc oxide, 150 DEG C-400 DEG C it are warming up under inert atmosphere, preferably 180 DEG C-350 DEG C, more preferably 200 DEG C-300 DEG C, being passed through gas phase bromine-containing compound gas, gas space velocity is 50h^-1-1000 h^-1, preferably 100h^-1-500h^-1；Can carry out at normal pressure during process, it is also possible to carry out under a certain pressure, system pressure is 0.1MPa-0.5MPa(absolute pressure), preferably 0.1MPa-0.3MPa(absolute pressure), the process time is 0.5h-8h, preferably 1h-4h.

Noble gas involved in the preparation method of above-mentioned bromomethane preparing isobutene catalyst is the gas that nitrogen, argon, helium etc. do not occur chemical reaction under the conditions of involved in the present invention, preferably nitrogen.

Described bromomethane preparing isobutene catalyst, is made up of zinc oxide, zinc bromide, auxiliary agent cerium oxide and titanium-silicon composite oxide carrier.Wherein, by catalyst weight content meter, zinc oxide weight content is 0.5%-20%, preferably 1%-15%, further preferred 1%-9%；Zinc bromide weight content is 10%-50%, preferably 15%-45%, further preferred 18%-39%；Auxiliary agent cerium oxide weight content is 0.5%-5%, preferably 1%-3%；In composite oxide carrier, titania weight content is 0.5%-10%, preferably 1%-5%, silica weight content 40%-80%, preferably 50%-75%.

In above-mentioned bromomethane preparing isobutene catalyst, less than 450 DEG C total acid content (NH₃-TPD) it is 0.5mmol/g-1.3mmol/g, preferably 0.6mmol/g-1.2mmol/g, further preferred 0.7mmol/g-1.1mmol/g, the acid content of 250 DEG C-350 DEG C accounts for the 20%-90% of less than 450 DEG C total acid contents, preferably 30%-80%, further preferred 40%-80%.

The application in preparing isobutene of the above-mentioned catalyst with Ti-Si composite oxide as carrier, hydrogen reducing activation is carried out including to catalyst, making the content of halogen in catalyst is the 20%-90% of total halogen content in reduction procatalyst, then the catalyst after making halide activate with above-mentioned hydrogen reducing contacts, to prepare isobutene..

In above-mentioned application, the condition of described hydrogen reducing activation makes the content of halogen in catalyst be preferably the 30%-80%, further preferred 40%-80% of total halogen content in reduction procatalyst.

In above-mentioned application, the mode of described hydrogen reducing activation includes under an inert atmosphere by catalyzer temperature-elevating to 300 DEG C-600 DEG C；Then passing to air speed is 200h^-1-2000h^-1Hydrogen or the mixed gas of hydrogen and noble gas, keep 2h-16h at 0.1MPa-0.5MPa, in mixed gas, hydrogen volume percentage composition is 10%-95%；Preferably, 350 DEG C-550 DEG C it are warming up to；Then passing to air speed is 500h^-1-1000h^-1Hydrogen or the mixed gas of hydrogen and noble gas, keep 4h-8h at 0.1MPa-0.3MPa, in described mixed gas, hydrogen volume percentage composition is 30%-90%.

The application of above-mentioned catalyst, also includes that halide contacts acquisition isobutene. with catalyst.The condition of described contact includes that reaction temperature is 150 DEG C-350 DEG C；Reaction pressure is 0.1MPa-5MPa；Air speed is 50h^-1-1000h^-1；It is highly preferred that reaction temperature is 180 DEG C-300 DEG C more preferably 200-270 DEG C；Reaction pressure is 0.1MPa-3MPa；Air speed is 200h^-1-500h^-1。

In above-mentioned application, described halide can be one or more in one or more in a halide, methylene halide, three halides, preferably bromomethane, methylene bromide, bromoform, more preferably bromomethane.

A kind of detailed description of the invention in above-mentioned application, including under inert atmosphere by catalyzer temperature-elevating to 300 DEG C-600 DEG C, preferably 350 DEG C-550 DEG C；Then passing to air speed is 200h^-1-2000h^-1, preferably 500h^-1-1000h^-1The mixed gas of hydrogen and noble gas, in 0.1MPa-0.5MPa(absolute pressure), preferably 0.1MPa-0.3MPa(absolute pressure) process 2h-16h, preferably 4h-8h after, be down to reaction temperature and be passed through halide and react.In described gaseous mixture, hydrogen volume percentage composition is 10%-95%, preferably 30%-90%, more preferably 50%-90%.

In above-mentioned application, raw material can also be the mixed gas of halide and noble gas, and in mixed gas, the volumetric concentration of halide is 10%-90%, preferably 30%-80%.

Noble gas involved in above-mentioned application is the gas that nitrogen, argon, helium etc. do not occur chemical reaction under the conditions of involved in the present invention, preferably nitrogen.

In above-mentioned application, the reaction of halide preparing isobutene can be carried out, such as fixed bed, fluid bed, fixed fluidized bed, moving bed, the reactor of the form such as slurry bed system or ebullated bed, preferably fixed bed, fluidized-bed reactor in existing any form reactor.

Compared with prior art, bromomethane height can be optionally converted into isobutene. by the method that the present invention relates to.In the present invention, utilize sol-gal process to be prepared for Ti-Si composite oxide, the titanium center of acquisition high dispersive can be made, and under the synergism of cerium promoter, it is achieved electronics is at ZnBr₂-ZnO-CeO₂-TiO₂-SiO₂Between transmission, promote catalyst removing of bromine in activation process, improve selective isobutene.Carry out bromomethane by the inventive method and convert preparing isobutene reaction, bromomethane conversion ratio more than 80%, selective isobutene more than 80%.The present invention relates to bromomethane conversion preparing isobutene method for preparing catalyst simple, it is easy to industrialization.Bromomethane of the present invention converts preparing isobutene method and has reaction condition gentleness, selectivity of product advantages of higher, easily realizes industrialization, and application prospect is boundless.

Detailed description of the invention

Further illustrate technology contents and the effect of the present invention below in conjunction with embodiment, but be not so limited the present invention.

In following example and comparative example, acidimetric estimation uses NH₃-TPD method, the INSTRUMENT MODEL of employing is MICROMERITICS company of U.S. AutoChem 2920 chemical adsorption instruments, concrete to measure process as follows: sample being cooled to 150 DEG C by helium purge after 1 hour at 450 DEG C, introduces the mixed gas of ammonia and helium, ammonia volume content 10%, Pulse adsorption reaches balance for five times；Helium purge 2 hours, then carries out ammonia with the programming rate temperature programming of 10 DEG C/min and is desorbed to 450 DEG C；Ammonia after desorption uses the detection of TCD detector, quantitative Analysis catalyst surface acid amount.

Embodiment 1

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 1h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.04:0.0125:2:35.Then mixed system is warming up to 65 DEG C, stirs 4h, form gel, be down to room temperature ageing 3h.90 DEG C of dry 6h, 500 DEG C of roasting 4h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂。

Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 70%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-1.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, CeO₂In terms of oxide, weight content is 2%, TiO₂In terms of oxide, weight content is 3%, and in catalyst, less than 450 DEG C total acid contents are 0.91mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 74.58% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 62.31%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 2

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 1h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.012:0.017:2:35.Then mixed system is warming up to 65 DEG C, stirs 4h, form gel, be down to room temperature ageing 3h.80 DEG C of dry 8h, 600 DEG C of roasting 2h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂。

Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 70%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-2.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, CeO₂In terms of oxide, weight content is 3%, TiO₂In terms of oxide, weight content is 1%, and in catalyst, less than 450 DEG C total acid contents are 0.82mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 78.95% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 58.37%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 3

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 2h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.063:0.006:2:20.Then mixed system is warming up to 50 DEG C, stirs 8h, form gel, be down to room temperature ageing 3h.100 DEG C of dry 4h, 400 DEG C of roasting 6h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂。

Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 70%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-3.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, CeO₂In terms of oxide, weight content is 1%, TiO₂In terms of oxide, weight content is 5%, and in catalyst, less than 450 DEG C total acid contents are 0.97mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 69.37% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 63.52%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 4

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 1h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.04:0.0125:1:35.Then mixed system is warming up to 65 DEG C, stirs 4h, form gel, be down to room temperature ageing 4h.90 DEG C of dry 6h, 500 DEG C of roasting 4h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 80 DEG C of dry 8h, 500 DEG C of roasting 4h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂。

Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 70%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-4.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 33%, and ZnO weight content in terms of oxide is 2%, CeO₂In terms of oxide, weight content is 2%, TiO₂In terms of oxide, weight content is 3%, and in catalyst, less than 450 DEG C total acid contents are 1.04mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 65.42% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 68.50%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 5

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 1h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.036:0.011:3:35.Then mixed system is warming up to 65 DEG C, stirs 4h, form gel, be down to room temperature ageing 3h.90 DEG C of dry 6h, 500 DEG C of roasting 4h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 120 DEG C of dry 4h, 400 DEG C of roasting 8h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂。

Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 70%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-5.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 27%, and ZnO weight content in terms of oxide is 6%, CeO₂In terms of oxide, weight content is 2%, TiO₂In terms of oxide, weight content is 3%, and in catalyst, less than 450 DEG C total acid contents are 0.87mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 70.08% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 63.51%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 6

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 0.5h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.03:0.009:2: 50.Then mixed system is warming up to 65 DEG C, stirs 4h, form gel, be down to room temperature ageing 3h.90 DEG C of dry 6h, 500 DEG C of roasting 4h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂。

Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 30%, and treatment conditions are 300 DEG C, 0.1MPa(absolute pressure), 100h^-1, time 4h, prepare bromomethane preparing isobutene catalyst, be designated as C-6.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 18%, and ZnO weight content in terms of oxide is 2%, CeO₂In terms of oxide, weight content is 2%, TiO₂In terms of oxide, weight content is 3%, and in catalyst, less than 450 DEG C total acid contents are 0.79mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 74.33% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 56.27%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 7

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 1h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.045:0.014:2:35.Then mixed system is warming up to 80 DEG C, stirs 2h, form gel, be down to room temperature ageing 2h.90 DEG C of dry 6h, 500 DEG C of roasting 4h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂。

Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 100%, and treatment conditions are 200 DEG C, 0.3MPa(absolute pressure), 500h^-1, time 1h, prepare bromomethane preparing isobutene catalyst, be designated as C-7.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 39%, and ZnO weight content in terms of oxide is 6%, CeO₂In terms of oxide, weight content is 2%, TiO₂In terms of oxide, weight content is 3%, and in catalyst, less than 450 DEG C total acid contents are 1.05mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 69.80% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 70.50%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 8

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 1h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.037:0.011:2:35.Then mixed system is warming up to 65 DEG C, stirs 4h, form gel, be down to room temperature ageing 3h.90 DEG C of dry 6h, 500 DEG C of roasting 4h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂。

Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 80%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-8.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, CeO₂In terms of oxide, weight content is 2%, TiO₂In terms of oxide, weight content is 3%, and in catalyst, less than 450 DEG C total acid contents are 0.93mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 72.59% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 90%, and activation condition is 350 DEG C, 0.3MPa(absolute pressure), 1000h^-1, soak time 8h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 63.08%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 30%, and reaction temperature is 260 DEG C, and reaction pressure is 3MPa(absolute pressure), air speed is 200h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 9

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 1h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.037:0.011:2:35.Then mixed system is warming up to 65 DEG C, stirs 4h, form gel, be down to room temperature ageing 3h.90 DEG C of dry 6h, 500 DEG C of roasting 4h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂。

Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 50%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-9.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, CeO₂In terms of oxide, weight content is 2%, TiO₂In terms of oxide, weight content is 3%, and in catalyst, less than 450 DEG C total acid contents are 0.89mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 73.40% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 50%, and activation condition is 550 DEG C, 0.1MPa(absolute pressure), 500h^-1, soak time 4h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 59.26%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 80%, and reaction temperature is 210 DEG C, and reaction pressure is 0.1MPa(absolute pressure), air speed is 500h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Comparative example 1

Prepare catalyst by embodiment 1, preparation process does not use bromination process.Detailed process is as follows:

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 1h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.04:0.0125:2:35.Then mixed system is warming up to 65 DEG C, stirs 4h, form gel, be down to room temperature ageing 3h.90 DEG C of dry 6h, 500 DEG C of roasting 4h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on prepared containing cerium titanium-silicon composite oxide carrier, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/CeO₂-TiO₂-SiO₂, prepare catalyst D-1.ZnO weight content in terms of oxide is 20%, CeO₂In terms of oxide, weight content is 2%, TiO₂In terms of oxide, weight content is 3%, and in catalyst, less than 450 DEG C total acid contents are 0.28mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 42.55% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Comparative example 2

Take catalyst C-1 without reduction activation, directly carry out bromomethane conversion reaction.Unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Comparative example 3

Weighing appropriate tetraethyl orthosilicate, be dissolved in deionized water, stir 1h, sequentially add the aqueous isopropanol of tetrabutyl titanate under room temperature, and cerous nitrate aqueous solution, after being sufficiently mixed, with material gauge in mixed system, each material ratio is for SiO₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.04:0.0125:2:35.Then mixed system is warming up to 65 DEG C, stirs 4h, form gel, be down to room temperature ageing 3h.90 DEG C of dry 6h, 500 DEG C of roasting 4h, prepare the titanium-silicon composite oxide carrier CeO Han cerium₂-TiO₂-SiO₂。

Weigh appropriate zinc bromide again to be dissolved in deionized water, use equi-volume impregnating to be carried on CeO₂-TiO₂-SiO₂Carrier, 100 DEG C of dry 6h, the lower 450 DEG C of roasting 6h of nitrogen atmosphere, prepare catalyst D-2.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, CeO₂In terms of oxide, weight content is 2%, TiO₂In terms of oxide, weight content is 3%, and in catalyst, less than 450 DEG C total acid contents are 1.32mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 64.71% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 35.90%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Table 1 catalyst reaction performance

Claims (26)

1. the preparation method of bromomethane preparing isobutene catalyst, it is characterised in that: comprise the steps:

(1) the sol-gal process preparation titanium-silicon composite oxide carrier containing auxiliary agent cerium is used；

(2) zinc oxide is introduced to step (1) resulting vehicle, dry, roasting；

(3) catalyst precarsor after introducing zinc oxide carries out bromination process making zinc oxide weight content in catalyst is 0.5%-20%；Zinc bromide weight content is 10%-50%.

Method the most according to claim 1, it is characterized in that: use the sol-gal process preparation titanium-silicon composite oxide carrier detailed process containing auxiliary agent cerium as follows described in step (1): to be dissolved in deionized water with tetraethyl orthosilicate for silicon source, add the aqueous isopropanol of tetrabutyl titanate, the aqueous solution containing cerium salt, hydrolyze after being sufficiently mixed, form gel, it is down to room temperature ageing again, after drying, roasting, prepares the titanium-silicon composite oxide carrier containing auxiliary agent cerium.

Method the most according to claim 2, it is characterised in that: with material gauge rate of charge as SiO in system₂:TiO₂:CeO₂: isopropanol: H₂O=1:0.005-0.19:0.002-0.04:0.5-5:10-100；The tetraethyl orthosilicate prehydrolysis time is 0.2h-4h；During tetrabutyl titanate hydrolysis, temperature is 40 DEG C-90 DEG C, and hydrolysis time is 1h-16h；Gel digestion time is 1h-8h；Described cerium salt is cerous nitrate, cerium chloride or cerous sulfate.

Method the most according to claim 2, it is characterised in that: described drying condition is 60 DEG C of-120 DEG C of dry 2h-16h；Described roasting condition is roasting 1h-8h under 300 DEG C of-700 DEG C of air atmospheres.

Method the most according to claim 1, it is characterised in that: zinc oxide described in step (2) introduces and uses impregnation method.

Method the most according to claim 5, it is characterized in that: concrete grammar is as follows: use the carrier that zinc solution impregnation steps (1) obtains, obtaining bromomethane preparing isobutene catalyst precarsor after drying, roasting, described drying condition is: temperature 60 C-150 DEG C, and the time is 1h-24h；Described roasting condition is: temperature 300 DEG C-600 DEG C；Time is 1h-24h.

Method the most according to claim 6, it is characterised in that: zinc salt is one or more in nitrate, hydrochlorate, acetate, citrate.

Method the most according to claim 1, it is characterised in that: bromination described in step (5) processes, and refers to use gas phase bromine-containing compound to process the sample of load zinc oxide.

Method the most according to claim 8, it is characterised in that: bromine-containing compound refers to one or more in bromomethane, methylene bromide, bromoform.

Method the most according to claim 1, it is characterised in that: using gas phase bromine-containing compound to carry out bromination process with the mixed gas of noble gas in step (3), bromomethane volumetric concentration is not less than 20%.

11. methods according to claim 1, it is characterized in that: in step (3), concrete bromination process is as follows: the sample of load zinc oxide is placed in continuous fixed bed reactor, being warming up to 150 DEG C-400 DEG C under inert atmosphere, be passed through gas phase bromine-containing compound gas, gas space velocity is 50h^-1-1000 h^-1；System pressure is 0.1MPa-0.5MPa, and the process time is 0.5h-8h.

12. methods according to claim 11, it is characterised in that: being warming up to 180 DEG C-350 DEG C under inert atmosphere, be passed through gas phase bromine-containing compound gas, gas space velocity is 100h^-1-500h^-1；System pressure is 0.1MPa-0.3MPa, and the process time is 1h-4h.

Catalyst prepared by 13. claim 1 to 12 either method, it is characterised in that: described catalyst is made up of zinc oxide, zinc bromide, auxiliary agent cerium oxide and titanium-silicon composite oxide carrier, and wherein, zinc oxide weight content is 0.5%-20%；Zinc bromide weight content is 10%-50%；Auxiliary agent cerium oxide weight content is 0.5%-5%；In composite oxide carrier, titania weight content is 0.5%-10%, silica weight content 40%-80%.

14. catalyst according to claim 13, it is characterised in that: zinc oxide weight content is 1%-15%；Zinc bromide weight content is 15%-45%；Auxiliary agent cerium oxide weight content is 1%-3%；In composite oxide carrier, titania weight content is 1%-5%, and silica weight content is 50%-75%.

15. catalyst according to claim 13, it is characterized in that: in catalyst, less than 450 DEG C total acid contents (NH3-TPD) are 0.5mmol/g-1.3mmol/g, preferably 0.6mmol/g-1.2mmol/g, further preferably 0.7mmol/g-1.1mmol/g, the acid content of 250 DEG C-350 DEG C accounts for the 20%-90% of less than 450 DEG C total acid contents, preferably 30%-80%, further preferred 40%-80%.

The application in preparing isobutene of the 16. arbitrary catalyst of claim 13-15, it is characterized in that: include catalyst is carried out hydrogen reducing activation, making the content of halogen in catalyst is the 20%-90% of total halogen content in reduction procatalyst, then the catalyst after making halide activate with above-mentioned hydrogen reducing contacts, to prepare isobutene..

17. application according to claim 16, it is characterised in that: the condition of described hydrogen reducing activation makes the content of halogen in catalyst be preferably the 30%-80%, preferably 40%-80% of total halogen content in reduction procatalyst.

18. application according to claim 16, it is characterised in that: the mode of described hydrogen reducing activation includes under an inert atmosphere by catalyzer temperature-elevating to 300 DEG C-600 DEG C；Then passing to air speed is 200h^-1-2000h^-1Hydrogen or the mixed gas of hydrogen and noble gas, keep 2h-16h at 0.1MPa-0.5MPa, in mixed gas, hydrogen volume percentage composition is 10%-95%.

19. application according to claim 18, it is characterised in that: it is warming up to 350 DEG C-550 DEG C；Then passing to air speed is 500h^-1-1000h^-1Hydrogen or the mixed gas of hydrogen and noble gas, keep 4h-8h at 0.1MPa-0.3MPa, in described mixed gas, hydrogen volume percentage composition is 30%-90%.

20. application according to claim 16, it is characterised in that: the condition of described contact includes that reaction temperature is 150 DEG C-350 DEG C；Reaction pressure is 0.1MPa-5MPa；Air speed is 50h^-1-1000h^-1。

21. application according to claim 20, it is characterised in that: reaction temperature is 180 DEG C-300 DEG C more preferably 200-270 DEG C；Reaction pressure is 0.1MPa-3MPa；Air speed is 200h^-1-500h^-1。

22. application according to claim 16, it is characterised in that: described halide is one or more in a halide, methylene halide, three halides.

23. application according to claim 16, it is characterised in that: described halide is one or more in bromomethane, methylene bromide, bromoform.

24. application according to claim 16, it is characterised in that: include catalyzer temperature-elevating to 300 DEG C-600 DEG C under inert atmosphere；Then passing to air speed is 200h^-1-2000h^-1The mixed gas of hydrogen and noble gas, after 0.1MPa-0.5MPa processes 2h-16h, be down to reaction temperature and be passed through halide and react, in described gaseous mixture, hydrogen volume percentage composition is 10%-95%.

25. application according to claim 24, it is characterised in that: include catalyzer temperature-elevating to 350 DEG C-550 DEG C under inert atmosphere；Then passing to air speed is 500h^-1-1000h^-1The mixed gas of hydrogen and noble gas, after 0.1MPa-0.3MPa processes 4h-8h, be down to reaction temperature and be passed through halide and react, in described gaseous mixture, hydrogen volume percentage composition is 30%-90%.

26. application according to claim 16, it is characterised in that: the reaction of halide preparing isobutene is carried out in fixed bed, fluid bed, fixed fluidized bed, moving bed, slurry bed system or fluidized bed reactor.