CN112717928A

CN112717928A - Catalyst for preparing butylene by dehydrogenating n-butane

Info

Publication number: CN112717928A
Application number: CN201910970925.1A
Authority: CN
Inventors: 吴省; 洪学思; 缪长喜; 吴文海; 张新玉
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2019-10-14
Filing date: 2019-10-14
Publication date: 2021-04-30

Abstract

The invention relates to a catalyst for n-butane dehydrogenation, which mainly solves the problem of low selectivity of an n-butane dehydrogenation catalyst prepared by the prior art. The dehydrogenation catalyst adopted by the invention takes VIB group of the periodic table of elements as a main active component, at least one element of La or Ce or an oxide thereof and at least one element of VIII B group noble metal or an oxide thereof as an auxiliary agent, and the carrier is selected from zirconia and/or titania modified alumina. The infrared characterization result of pyridine shows that the B acid and the L acid in the catalyst have the following relationship, m_B/m_LIn the range of 0 to 3, wherein m_LMeans the amount of L-acid in the catalyst, m_BRefers to the acid content of B. The catalyst prepared by the invention better solves the problem and can be used for industrial application of n-butane dehydrogenation.

Description

Catalyst for preparing butylene by dehydrogenating n-butane

Technical Field

The invention relates to a catalyst for preparing butylene by dehydrogenating n-butane.

Background

The dehydrogenation of n-butane generally comprises oxidative dehydrogenation and direct dehydrogenation, wherein the oxidative dehydrogenation mostly adopts vanadium-based catalysts, such as VMgO system, VSiO system and catalytic system taking molecular sieve as a carrier; chromium-based catalyst CrOx/Al₂O₃And molecular sieve support systems, and in addition, molybdate and pyrophosphate systems. Although the process is not limited by thermodynamics and has higher conversion rate, the process is often over-oxidized, produces more byproducts and results in lower selectivity. The direct dehydrogenation system mainly uses a catalytic system with noble metal Pt as an active component and a catalytic system with Cr as an active component, and because the reaction is limited by thermodynamics, the direct dehydrogenation system is a strong endothermic reaction and needs to react at a higher reaction temperature and a lower pressure to obtain a higher butane conversion rate, but side reactions such as cracking, coking and the like can be caused at a high temperature, so that the selectivity of the catalyst is reduced, and the development of a butane dehydrogenation catalyst with good performance is very important.

Aluminum oxide or alumina is a common catalyst support in dehydrogenation catalysts, and the preparation method, pore structure and modification method thereof can cause the catalyst to show different performances. For alumina or its precursors, such as gibbsite, boehmite, diaspore, etc., which have different surface areas, pore size distributions, surface acidity, and crystal structures, different crystal forms of alumina are formed at different heating and calcination temperatures. For example, boehmite is used as a precursor, and gamma-alumina is present at 500 to 850 ℃, theta-alumina at 850 to 1050 ℃, eta-alumina at 1050 to 1150 ℃ and alpha-alumina at a temperature higher than 1150 ℃. Besides, one can also modify the carrier by using various auxiliary agents or stabilizers, such as alkaline earth metals and rare earth metals, and transition element metals, so as to adapt to the dehydrogenation reaction of the low-carbon alkane. Chinese patent 103990454A discloses an excellent anti-carbon deposition low-carbon alkane dehydrogenation catalyst and a preparation method thereof, wherein the catalyst is gamma-Al after hydrothermal treatment₂O₃The pellet is used as a carrier, and is impregnated with a Pt active component and Sn, Na and La auxiliaries. Under the same evaluation conditions, the catalyst shows better carbon deposition resistance than the catalyst prepared by common alumina ballsForce and excellent dehydrogenation performance of the light alkane, but no specific value is given. Chinese patent CN107398296 studies a catalyst carrier prepared by mixing alumina and mesoporous molecular sieve and its preparation method, the mixed mesoporous carrier is prepared by adding mesoporous molecular sieve and many kinds of auxiliary agents into a conventional alumina source, mixing, extruding into strips, molding, then performing hydrothermal treatment, drying, and roasting to obtain the dehydrogenation catalyst carrier. The carrier has high mechanical strength and good thermal stability, but the selectivity of the catalyst prepared on the basis of the carrier to isobutene is lower than 80%. Chinese patent 101125298 discloses a catalyst for dehydrogenation of propane to produce propylene, which uses alumina modified mesoporous molecular sieve as carrier. The propylene selectivity, evaluated under experimentally set conditions, was 93%, but the propane conversion was lower, only 17%.

Although the direct n-butane dehydrogenation catalyst has made a certain progress, the existing Cr catalyst still has the problems of low selectivity, low strength when single alumina is used as a carrier and weak carbon deposition resistance, and the commercial application of preparing corresponding n-butene with high added value by using n-butane as a raw material is greatly influenced.

Disclosure of Invention

The invention aims to solve one of the technical problems and provides a zirconia and/or titania modified alumina carrier and a preparation method thereof. The second technical problem to be solved by the invention is to provide an n-butane dehydrogenation catalyst aiming at the problem of low activity of the n-butane dehydrogenation catalyst in the prior art, and also provide a catalyst preparation method corresponding to the second technical problem. The third technical problem to be solved by the present invention is to provide a catalyst corresponding to the second technical problem to be solved for n-butane dehydrogenation.

In order to solve one of the above technical problems, the technical scheme adopted by the invention is as follows: a catalyst for n-butane dehydrogenation uses VIB group of the periodic table of elements as a main active component, at least one element of La or Ce or an oxide thereof and at least one element of VIIIB group noble metal or an oxide thereof as an auxiliary agent, and a carrier is selected from zirconia and/or titania modified alumina. The result of pyridine infrared characterization shows that L acid in the catalystMass ratio m of B acid to B acid_B/m_LIn the range of 0 to 1, wherein m_LMeans the amount of L-acid in the catalyst, m_BRefers to the acid content of B.

The pyridine infrared detection instrument comprises: a Nicolet 5700 detector of the American Thermo Fisher company is adopted, and the detection method comprises the following steps: firstly, putting the tabletted sample into a sample cell, heating to 400 ℃ at the temperature of 3 ℃/min, and removing other impurities, wherein the pressure is lower than 0.1 Pa; cooling to room temperature, adsorbing pyridine to saturation state, heating at a speed of 3 deg.C/min under the condition of less than 0.1Pa for desorption, and heating every 2cm^-1Recording once until the desorption is finished at 200 ℃; the measurement conditions were the same for each measurement, and the size, thickness, etc. of the samples were consistent.

In the technical scheme, the weight part of the Cr and/or W element or the oxide thereof is 5-20 parts by weight of the n-butane catalyst.

In the technical scheme, the weight part of the Cr and/or W element or the oxide thereof is 10-18 parts by weight of the n-butane catalyst.

In the above technical solution, it is more preferable that the alloy simultaneously includes Cr and W elements or oxides thereof, wherein the weight ratio of Cr to W element is: (0.1-9): 1. in this case, the Cr element and the W element are used together, and have an unexpected synergistic effect in improving the catalyst activity of the n-butane dehydrogenation catalyst.

In the above technical solution, preferably, the alloy simultaneously includes Cr and W elements or oxides thereof, wherein the weight ratio of Cr to W elements is: (0.25-4): 1.

in the technical scheme, the part of La and/or Ce element selected from lanthanide series elements in the periodic table of elements or oxides thereof is 0.01-3 parts by weight of the n-butane catalyst.

In the technical scheme, the part of the noble metal element selected from the VIIIB group of the periodic table of elements or the oxide thereof is 0.01-2 parts by weight of the n-butane catalyst, wherein the noble metal element selected from the IIIA group is at least one of Pt, Pd, Ru and Rh.

In the above technical solution, more preferably, the noble metal element of group VIIIB of the periodic table or the oxide thereof is a mixture of Pt and Ru.

In the above technical solution, more preferably, the noble metal element of group VIIIB of the periodic table or the oxide thereof is a mixture of Pd and Ru.

In the above technical solution, more preferably, the noble metal element of group VIIIB of the periodic table or the oxide thereof is a mixture of Pt and Rh.

In the above technical solution, more preferably, the noble metal element of group VIIIB of the periodic table or the oxide thereof is a mixture of Pd and Rh.

In the technical scheme, the preferable range of the part of the noble metal element selected from the VIIIB group of the periodic table of elements or the oxide thereof is 0.1-1 part by weight of the n-butane catalyst.

In the above technical solutions, as the most preferable technical solution, the group viii B noble metal element or its oxide is a mixture of Pt, Pd and Ru or Rh. In this case, the use of noble group VIIIB metals or mixtures of their oxides Pt, Pd and Ru or Rh in the catalyst together has an unexpected synergistic effect in increasing the catalyst selectivity of the n-butane dehydrogenation catalyst.

In the technical scheme, La and/or Ce elements or oxides thereof and VIIIB group noble metal elements or oxides thereof in the lanthanide series are jointly used, so that unexpected synergistic effect is achieved in the aspect of improving the catalyst selectivity of the n-butane dehydrogenation catalyst.

The Cr element and the W element are used together and cooperate with lanthanide La andor Ce and VIIIB elements, so that the catalyst has unexpected synergistic effect on the aspect of improving the catalyst selectivity of the n-butane dehydrogenation catalyst.

In the above technical process, the n-butane dehydrogenation catalyst obtained is characterized in that m in L acid and B acid in the catalyst_B/m_LThe preferable range is 0 to 1, and the more preferable range is 0 to 0.8. On a well performing dehydrogenation catalyst, there is mainly L acid, and almost no B acid.

In the technical scheme, the adopted alumina carrier modified by zirconia and/or titania.

In order to solve the second technical problem, the catalyst carrier for n-butane dehydrogenation, namely the alumina carrier modified by zirconia and/or titania prepared by a hydrothermal method, adopts the technical scheme that:

a) soluble bauxite, zirconium salts and/or titanium salts;

b) adding a proper amount of alkali, and adjusting the pH value to 8-12 to enable the salt to form a colloid; transferring the obtained sample into a high-pressure kettle, and carrying out hydrothermal reaction for 6-72 hours at the temperature of 110-200 ℃;

c) and cooling, washing and filtering the sample obtained by the hydrothermal process to obtain a solid sample, and drying and roasting the solid sample to obtain the catalyst carrier.

In order to obtain the alumina carrier modified by the zirconia and/or the titania, the carrier is optimally prepared by adopting the following conditions:

1) the aluminum source is selected from one or more of boehmite, aluminum hydroxide, aluminum nitrate, aluminum chloride, aluminum sulfate and the like, the zirconium salt is selected from zirconium nitrate, n-butyl zirconium and the like, and the titanium salt is selected from titanium dioxide, tetrabutyl titanate and the like; wherein the ratio of alumina to zirconia and/or titania, calculated as the final oxide form, is in the range by weight: (10-100) 1: 1.

2) The alkali is selected from one or more of sodium hydroxide, ammonia water, potassium hydroxide and the like;

3) cooling the sample to room temperature after hydrothermal treatment, and washing the sample for 3-5 times by using deionized water until Cl is contained^-、SO₄ ^-The ion content is less than 100 ppm; drying at 40-150 ℃ for 2-24 hours; the roasting temperature is 300-800 ℃, and the roasting time is 2-20 h.

In the technical scheme, the preferred range of the hydrothermal treatment temperature of the alumina carrier modified by zirconia and/or titania is 120-160 ℃, and the preferred range of the hydrothermal reaction time is 6-24 hours.

In the technical scheme, the preferable range of the post-treatment drying temperature of the alumina carrier modified by zirconia and/or titania is 80-120 ℃, and the preferable range of the drying time is 6-12 hours.

In the technical scheme, the preferable range of the post-treatment roasting temperature of the alumina carrier modified by zirconia and/or titania is 400-600 ℃, and the preferable range of the roasting time is 4-10 hours.

The zirconia and/or titania modified alumina carrier comprises 5-20 parts of zirconia and/or titania by weight, wherein when the zirconia and/or titania are added simultaneously, the parts ratio is (0.05-20): 1.

in the technical scheme, the content of the zirconium oxide and/or the titanium oxide is 1-5 parts by weight;

in the technical scheme, the content of the zirconium oxide and/or the titanium oxide is (0.1-10) in parts by weight: 1.

in the technical scheme, the content of the zirconium oxide and/or the titanium oxide is (0.5-5) in parts by weight: 1.

in order to solve the third technical problem, the technical scheme adopted by the invention is as follows: a catalyst for n-butane dehydrogenation and a preparation method thereof comprise the following steps:

a) tabletting and screening the catalytic carrier to obtain a pretreated carrier I; screening by a sieve of 20-40 meshes, and roasting at 400-600 ℃ for 0.5-12 hours to obtain a pretreated carrier I;

b) mixing a carrier I with a required amount of soluble salt solution (including but not limited to chromium nitrate, chromium chloride, basic chromium sulfate, chromium potassium sulfate, potassium tungstate, sodium tungstate and the like) containing Cr and/or W, soluble salt soluble salts (including but not limited to chloroplatinic acid, potassium tetrachloroplatinate and the like, and/or chlorites, chlorites of Pd, Ru and Rh, organic complexes and the like) in lanthanide series of the periodic table and VIII B group of the periodic table to obtain a mixture I, and adjusting the pH value of the mixture I to be 1-4 by using inorganic ammonia or inorganic ammonium salt solution at the temperature of 10-80 ℃ to obtain a mixture II;

c) and filtering and drying the mixture II to obtain the required n-butane dehydrogenation catalyst. And soaking the mixture II for 0.5-8 hours at the temperature of 10-100 ℃, filtering, drying, and roasting at 300-800 ℃ for 0.5-12 hours to obtain the required n-butane dehydrogenation catalyst.

The soluble salt of Cr can be selected from one of nitrate, acetate or oxalate; the W soluble salt is selected from tungstate, metatungstate or acetate. La and/or Ce is selected from one of soluble salts such as nitrate, chloride or sulfate; pt and Pd are selected from corresponding chlorate, or complex salt such as chloric acid; ru and Rh are selected from one of soluble salts such as nitrate, chlorate and the like.

In the technical scheme, the preferable scheme of the inorganic ammonia or inorganic ammonium salt is selected from ammonia water, ammonium carbonate or ammonium bicarbonate, and the preferable range of the pH value of the solution is 1-7, and the more preferable range is 1-3; the preferred range of the dipping temperature is 50-80 ℃, the preferred range of the dipping time is 1-3 hours, the preferred range of the roasting temperature of the catalyst is 400-600 ℃, and the preferred range of the roasting time is 4-8 hours.

The invention solves the technical problem four, and adopts the technical scheme as follows: the reaction raw material is n-butane, and the reaction conditions are as follows: the reaction pressure is 0-1 MPa, the temperature is 500-620 ℃, and the mass space velocity is 0.1-10 h^-1(ii) a And the reaction raw material is in contact reaction with the catalyst to obtain n-butene. The catalyst prepared by the method is subjected to activity evaluation in an isothermal fixed bed reactor, and the process for preparing n-butene by n-butane dehydrogenation comprises the following steps:

the flow of n-butane gas is adjusted through a mass flow meter, the n-butane gas enters a preheating zone to be preheated, and then enters a reaction zone, a heating section and a reaction section of a reactor are heated by electric heating wires to reach a preset temperature, and the reactor is a reaction tube with the inner diameter of phi 9 mm-phi 6mm and the length of 400-580 mm. The reacted gas passes through a condensing tank and enters a gas phase chromatography for analyzing the composition of the gas.

The catalyst evaluation conditions in the isothermal fixed bed reactor were as follows: loading about 0.5 g of catalyst into isothermal reactor with internal diameter of phi 9 mm-phi 6mm, reaction pressure being normal pressure and gas mass space velocity of 1.0 hr^-1And the reaction temperature was 540 ℃. The conversion rate of the n-butane is obtained by multiplying the content of the reacted n-butane, which is the sum of the contents of all gas-phase products, by 100%; the selectivity of n-butene includes butene-1 and butene-2, and the content of n-butene is calculated by the percentage of other gas components except n-butane after reaction, namely the content of n-buteneIs divided by C₁、C₂、C₃And the percentage of the sum of the n-butene contents.

The Cr catalyst used in the direct dehydrogenation of n-butane is easy to deposit carbon to make the catalyst have low activity because of its strong acidity on the surface. The W element of VIB group has various variable valence states, Cr and/or W are combined together, lanthanide La and/or Ce in the periodic table of elements is added simultaneously, so that the acid-base distribution, the surface characteristics and the like on the surface of the catalyst can be effectively changed, the catalyst has higher selectivity, and in addition, Pt, Pd, Ru, Rh and the like in the VIIIB group element serving as a dehydrogenation active component can be used for corresponding dehydrogenation to improve the catalytic activity site; by using the alumina carrier modified by the zirconium oxide and/or the titanium oxide which is subjected to hydrothermal treatment, the carrier strength can be improved, and the selectivity of the catalyst can be improved. When the catalyst obtained by adopting the conditions is used in the n-butane dehydrogenation reaction, the n-butane conversion rate is 38 percent, the n-butene selectivity is 87 percent, and better technical effects are obtained.

The invention is further illustrated by the following examples.

Drawings

FIG. 1 shows the L acid and B acid in the infrared spectrum of pyridine in the catalyst,

the test results of the sample obtained in example 1 of the present invention for catalyst 1 show that only L acid and no B acid exist in the catalyst, and the ratio m between the B acid and the L acid_B/m_LIs 0.

Catalyst 2 is the catalyst test result obtained in example 4 of the present invention, the sample has L acid and B acid, the ratio m between B acid and L acid_B/m_LIs 0.5.

Catalyst 3 is comparative example 3 of the present invention, a small amount of B acid is present in the catalyst, and no L acid is present, m_L/m_BIs 0.

Detailed Description

[ example 1 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. The sample was transferred to a high pressure of 1 literCarrying out hydrothermal treatment for 8 hours in a reaction kettle at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

63.18 g of chromium nitrate, 2.66 g of lanthanum nitrate and 1.14 g of chloroplatinic acid are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the sample is taken out and filtered after being soaked in a water bath at 80 ℃ for 1 hour, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours, so that the required catalyst is obtained. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LThe pyridine infrared spectrum of 0 is shown as catalyst 1 in the attached figure 1.

The flow of n-butane gas is regulated by a mass flow meter, the n-butane gas enters a preheating zone for preheating, and then enters a reaction zone, a heating section and a reaction section of the reactor are heated by electric heating wires to reach a preset temperature, and the reactor is a quartz tube with the inner diameter of phi 6mm and the length of 400 mm. The reacted gas was passed through a condensing pot and then analyzed for composition by gas chromatography.

The catalyst evaluation conditions in the isothermal fixed bed reactor were as follows: 0.5 g of the catalyst is loaded into the isothermal fixed bed reactor, the reaction pressure is normal pressure, and the gas mass space velocity is 1.0 hour^-1And the reaction temperature was 540 ℃. The results are shown in Table 1.

[ example 2 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 11. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 12 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

Weighing 63.1Adding 8 g of chromium nitrate, 2.66 g of lanthanum nitrate and 0.72 g of palladium chloride into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titanium oxide, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.002. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 3 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 9. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at the temperature of 80 ℃, cooling to room temperature, washing with 3 liters of deionized water for 3 times, drying in an oven at the temperature of 100 ℃ for 4 hours, and roasting in a muffle furnace at the temperature of 550 ℃ for 2 hours to obtain the modified alumina carrier.

63.18 g of chromium nitrate, 2.66 g of lanthanum nitrate and 0.72 g of palladium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the sample is taken out and filtered after being soaked in a water bath at 80 ℃ for 1 hour, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours, so that the required catalyst is obtained. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 4 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 400 ℃ for 10 hours to obtain the modified alumina carrier.

63.18 g of chromium nitrate, 1.51 g of lanthanum chloride and 0.78 g of ruthenium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the sample is taken out and filtered after being immersed in a water bath at 80 ℃ for 1 hour, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.5. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 5 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 9. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 4 hours to obtain the modified alumina carrier.

63.18 g of chromium nitrate, 2.66 g of lanthanum nitrate and 1.14 g of rhodium nitrate are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the sample is taken out and filtered after being soaked in a water bath at 80 ℃ for 1 hour, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours, so that the required catalyst is obtained. Subjecting the catalyst to an infrared pyridine adsorption test, whereinM ratio of B acid to L acid_B/m_LIs 0.01. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 6 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 16 hours at the temperature of 100 ℃, cooling to room temperature, washing with 3 liters of deionized water for 5 times, drying in an oven at the temperature of 100 ℃ for 8 hours, and roasting in a muffle furnace at the temperature of 550 ℃ for 2 hours to obtain the modified alumina carrier.

Weighing 13.12 g of ammonium tungstate, 2.66 g of lanthanum nitrate and 1.14 g of chloroplatinic acid, adding the ammonium tungstate, the lanthanum nitrate and the chloroplatinic acid into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at the temperature of 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at the temperature of 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to roast the sample at the temperature of 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 7 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 4 hours at 160 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

13.12 g of ammonium tungstate, 2.66 g of lanthanum nitrate and 0.72 g of palladium chloride were weighed and added to 100 ml of deionized waterAdding 86.5 g of the zirconia and/or titania modified alumina carrier into water, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at the temperature of 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at the temperature of 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to roast the sample at the temperature of 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 1. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 8 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 80 ℃ for 10 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

Weighing 13.12 g of ammonium tungstate, 2.66 g of lanthanum nitrate and 1.19 g of ruthenium nitrate, adding the materials into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to roast the sample at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 9 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. Mixing the aboveThe sample is moved into a 1L high-pressure reaction kettle, is subjected to hydrothermal treatment for 8 hours at the temperature of 120 ℃, is cooled to room temperature, is washed for 3 times by using 3L deionized water, is dried for 12 hours in an oven at the temperature of 80 ℃, and is roasted for 2 hours in a muffle furnace at the temperature of 550 ℃ to obtain the modified alumina carrier.

Weighing 13.12 g of ammonium tungstate, 2.66 g of lanthanum nitrate and 1.04 g of rhodium chloride, adding the mixture into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to roast the sample at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.05. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 10 ]

77.4 grams of alumina was weighed into a 500 ml beaker, 200 grams of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 9. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at the temperature of 100 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at the temperature of 100 ℃ for 8 hours, and roasting in a muffle furnace at the temperature of 550 ℃ for 2 hours to obtain the modified alumina carrier.

63.18 g of chromium nitrate, 0.3 g of lanthanum nitrate and 1.14 g of chloroplatinic acid are weighed and added into 100 ml of deionized water, 87.4 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the sample is taken out and filtered after being soaked in a water bath at 80 ℃ for 1 hour, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours, so that the required catalyst is obtained. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. N-butane feedstock and the above catalystThe reaction was carried out under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 11 ]

74.5 g of alumina is weighed into a 500 ml beaker, 200 g of deionized water is added and the mixture is stirred uniformly. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 9. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 600 ℃ for 2 hours to obtain the modified alumina carrier.

63.18 g of chromium nitrate, 4.53 g of lanthanum chloride and 1.14 g of chloroplatinic acid are weighed and added into 100 ml of deionized water, 84.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the sample is taken out and filtered after being immersed in a water bath at 80 ℃ for 1 hour, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours, so that the required catalyst is obtained. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 12 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 4 hours, and roasting in a muffle furnace at 600 ℃ for 6 hours to obtain the modified alumina carrier.

63.18 g of chromium nitrate, 0.97 g of cerium sulfate and 1.14 g of chloroplatinic acid were weighed into 100 ml of deionized water, and 86.5 g of the above zirconia and/or titania modified alumina support was added thereto, followed by 2 g.Adjusting the pH value of the solution to 3.5 by 5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 13 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

63.18 g of chromium nitrate, 2.66 g of lanthanum nitrate, 0.57 g of chloroplatinic acid and 0.39 g of ruthenium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by 2.5% of ammonia water, then the solution is immersed in a water bath at the temperature of 80 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at the temperature of 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and roasted at the temperature of 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.1. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 14 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. Transferring the sample into a 1L high-pressure reaction kettle, and adding water at 120 deg.CAnd (3) carrying out heat treatment for 8 hours, cooling to room temperature, washing with 3 liters of deionized water for 3 times, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

63.18 g of chromium nitrate, 2.66 g of lanthanum nitrate, 0.57 g of chloroplatinic acid and 0.52 g of rhodium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by 2.5% of ammonia water, then the solution is immersed in a water bath at the temperature of 80 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at the temperature of 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and roasted at the temperature of 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.02. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 15 ]

13.12 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.57 g of chloroplatinic acid and 0.39 g of ruthenium chloride were weighed into 100 ml of deionized water, and 86.5 g of the above-mentioned zirconia and/or titania-modified specific surface area 117m²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 7 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m of B acid to L acid_B/m_LWas 0.08. N-butanal sourceThe reaction of the above catalyst with the above catalyst was carried out under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 16 ]

Weighing 13.12 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.57 g of chloroplatinic acid and 0.52 g of rhodium chloride, adding the materials into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, adjusting the pH value of the solution to 1 by using 2.5% of ammonia water, soaking the solution in a water bath at the temperature of 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at the temperature of 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at the temperature of 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 17 ]

63.18 g of chromium nitrate, 2.66 g of lanthanum nitrate, 0.36 g of palladium chloride and 0.39 g of ruthenium chloride were weighed into 100 ml of deionized water, and 86.5 g of the above mixture was addedThe pH value of the zirconia and/or titania modified alumina carrier is adjusted to 3.5 by 2.5 percent ammonia water, then the alumina carrier is immersed in water bath at the temperature of 80 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at the temperature of 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and roasted at the temperature of 550 ℃ for 4 hours, so that the required catalyst is obtained. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 18 ]

63.18 g of chromium nitrate, 2.66 g of lanthanum nitrate, 0.36 g of palladium chloride and 0.52 g of rhodium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by 2.5% of ammonia water, then the sample is immersed in a water bath at 80 ℃ for 1 hour, then the sample is taken out and filtered, dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours, so that the required catalyst is obtained. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.05. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 19 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. Transferring the samplePutting the mixture into a 1L high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at the temperature of 120 ℃, cooling the mixture to room temperature, washing the mixture for 3 times by using 3L deionized water, drying the mixture in a 100 ℃ oven for 8 hours, and roasting the dried mixture in a 550 ℃ muffle furnace for 2 hours to obtain the modified alumina carrier.

13.12 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.36 g of palladium chloride and 0.39 g of ruthenium chloride were weighed into 100 ml of deionized water, and 86.5 g of the above-mentioned zirconia and/or titania-modified specific surface area 117m²The preparation method comprises the following steps of (1)/g, adjusting the pH value of an alumina carrier with a pore diameter of 15nm to 7 by using 2.5% ammonia water, then soaking in a water bath at 80 ℃ for 1 hour, taking out a sample, filtering, drying in an oven at 120 ℃ for 8 hours, and then putting the sample into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m of B acid to L acid_B/m_LIs 0.002. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 20 ]

Weighing 13.12 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.36 g of palladium chloride and 0.52 g of rhodium chloride, adding the materials into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, adjusting the pH value of the solution to 1 by using 2.5% ammonia water, soaking the solution in a water bath at the temperature of 80 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at the temperature of 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at the temperature of 550 ℃ for 4 hours to obtain the required catalyst. The catalyst was subjected to an infrared pyridine adsorption test in which B and L acids were presentRatio m_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 21 ]

31.6 g of chromium nitrate, 3.18 g of tungsten acetate, 2.66 g of lanthanum nitrate and 1.14 g of chloroplatinic acid are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the solution is soaked in a water bath at 50 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 22 ]

83.5 g of alumina is weighed into a 500 ml beaker, 200 g of deionized water is added, and the mixture is stirred uniformly. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

Weigh 13.17 grams of chromium nitrate, 2.73 grams of ammonium tungstate, 2.66 grams of lanthanum nitrate, 1.14 grams of chlorinePlatinic acid is added into 100 ml deionized water, then 93.5 g of alumina carrier modified by the zirconia and/or the titania is added, 2.5% ammonia water is used for adjusting the pH value of the solution to 3.5, then the solution is soaked in water bath at 50 ℃ for 1 hour, then a sample is taken out and filtered, the sample is dried in a 120 ℃ oven for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours, thus obtaining the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.3. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 23 ]

66.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

57.60 g of chromium nitrate, 11.93 g of ammonium tungstate, 2.66 g of lanthanum nitrate and 1.14 g of chloroplatinic acid are weighed and added into 100 ml of deionized water, 77.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the solution is immersed in a water bath at 50 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.4. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 24 ]

79.5 g of alumina is weighed into a 500 ml beaker, 200 g of deionized water is added, and the mixture is stirred uniformly. Then 5 g of TiO were added₂And 19.27 g of n-butylZirconium alkoxide, ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

26.33 g of chromium nitrate, 5.46 g of ammonium tungstate, 2.66 g of lanthanum nitrate and 1.14 g of chloroplatinic acid are weighed, added into 100 ml of deionized water, then 89.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by 2.5% of ammonia water, then the sample is immersed in a water bath at 50 ℃ for 1 hour, taken out and filtered, dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.06. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 25 ]

68.5 g of alumina is weighed into a 500 ml beaker, 200 g of deionized water is added, and the mixture is stirred uniformly. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

Weighing 52.66 g of chromium nitrate, 10.93 g of ammonium tungstate, 2.66 g of lanthanum nitrate and 1.14 g of chloroplatinic acid, adding the chromium nitrate, the ammonium tungstate, the lanthanum nitrate and the chloroplatinic acid into 100 ml of deionized water, adding 78.5 g of the alumina carrier modified by the zirconia and/or the titanium oxide, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. Infrared pyridine treatment of catalystAdsorption test, in which the ratio m in B and L acids_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 26 ]

31.6 g of chromium nitrate, 6.56 g of ammonium tungstate, 2.66 g of lanthanum nitrate and 0.78 g of palladium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the solution is immersed in a water bath at 50 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and calcined at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 27 ]

31.6 grams of chromium nitrate, 6.56 grams of ammonium tungstate, 2.66 grams of nitric acid were weighedLanthanum and 0.78 g of ruthenium chloride are added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by 2.5% ammonia water, then the solution is immersed in a water bath at 50 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at 120 ℃ for 8 hours, and the sample is put into a muffle furnace and roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 28 ]

31.6 g of chromium nitrate, 6.56 g of ammonium tungstate, 2.66 g of lanthanum nitrate and 1.04 g of rhodium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the solution is immersed in a water bath at 50 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and calcined at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 29 ]

76.5 g of alumina was weighed into a 500 ml beaker, 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, ammonia was added dropwise at a rate of 20ml/min to give a pH of 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

39.5 g of chromium nitrate, 8.2 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.57 g of chloroplatinic acid and 0.39 g of ruthenium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the solution is soaked in a water bath at 50 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.02. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 30 ]

Weighing 12.64 g of chromium nitrate, 10.50 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.57 g of chloroplatinic acid and 1.14 g of rhodium chloride, adding the mixture into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required productThe catalyst of (1) is subjected to an infrared pyridine adsorption test, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 31 ]

Weighing 50.56 g of chromium nitrate, 2.62 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.57 g of chloroplatinic acid and 0.39 g of ruthenium chloride, adding the mixture into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0.01. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 32 ]

31.6 g of chromium nitrate, 6.56 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.57 g of chloroplatinic acid and 1.14 g of rhodium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the solution is soaked in a water bath at 50 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and roasted at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 33 ]

12.64 g of chromium nitrate, 10.50 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.36 g of palladium chloride and 0.39 g of ruthenium chloride are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the solution is immersed in a water bath at 50 ℃ for 1 hour, a sample is taken out and filtered, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace and calcined at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

[ example 34 ]

76.5 grams of alumina was weighedThe mixture was added to a 500 ml beaker, and 200 g of deionized water was added and stirred well. Then 5 g of TiO were added₂And 19.27 g of zirconium n-butoxide, and aqueous ammonia was added dropwise at a rate of 20ml/min to adjust the pH to 10. And (2) transferring the sample into a 1-liter high-pressure reaction kettle, carrying out hydrothermal treatment for 8 hours at 120 ℃, cooling to room temperature, washing for 3 times by using 3 liters of deionized water, drying in an oven at 100 ℃ for 8 hours, and roasting in a muffle furnace at 550 ℃ for 2 hours to obtain the modified alumina carrier.

Weighing 50.56 g of chromium nitrate, 2.62 g of ammonium tungstate, 2.66 g of lanthanum nitrate, 0.36 g of palladium chloride and 1.14 g of rhodium chloride, adding the mixture into 100 ml of deionized water, adding 86.5 g of the zirconia and/or titania modified alumina carrier, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. Carrying out infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 0. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

Comparative example 1

Weighing 63.2 g of chromium nitrate and 3.28 g of ammonium tungstate, adding the chromium nitrate and the ammonium tungstate into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titanium oxide, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. Performing infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 5. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

Comparative example 2

Weighing 13.12 g of ammonium tungstate, adding the ammonium tungstate into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. Performing infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LIs 2. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

Comparative example 3

Weighing 13.12 g of ammonium tungstate, adding the ammonium tungstate into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, adjusting the pH value of the solution to 3.5 by using 2.5% ammonia water, soaking the solution in a water bath at 50 ℃ for 1 hour, taking out a sample, filtering the sample, drying the sample in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. Performing infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_L/m_BTo 0, n-butane starting material is reacted with the above-mentioned catalystThe reaction was carried out under the same conditions as in example 1, and the results are shown in Table 1.

Comparative example 4

63.18 g of chromium nitrate, 0.68 g of sodium carbonate and 3.03 g of ferric nitrate are weighed and added into 100 ml of deionized water, 86.5 g of the alumina carrier modified by the zirconia and/or the titania are added, the pH value of the solution is adjusted to 3.5 by using 2.5% ammonia water, then the sample is taken out and filtered after being soaked in a water bath at 50 ℃ for 1 hour, the sample is dried in an oven at 120 ℃ for 8 hours, and then the sample is put into a muffle furnace to be roasted at 550 ℃ for 4 hours, so that the required catalyst is obtained. Performing infrared pyridine adsorption test on the catalyst, wherein the ratio m of B acid to L acid_B/m_LIs 4.5. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

Comparative example 5

Weighing 15.8 g of chromium nitrate and 13.12 g of ammonium tungstate, adding the chromium nitrate and the ammonium tungstate into 100 ml of deionized water, adding 86.5 g of the alumina carrier modified by the zirconia and/or the titania, and adjusting the pH value of the solution to the value of 2.5 percent ammonia water3.5, soaking in a water bath at 50 ℃ for 1 hour, taking out the sample, filtering, drying in an oven at 120 ℃ for 8 hours, and roasting the sample in a muffle furnace at 550 ℃ for 4 hours to obtain the required catalyst. Performing infrared pyridine adsorption test on the catalyst, wherein the ratio m in B acid and L acid_B/m_LWas 3.2. The n-butane starting material was reacted with the above-mentioned catalyst under the same reaction conditions as in example 1, and the results are shown in Table 1.

TABLE 1

Claims

1. A catalyst for n-butane dehydrogenation comprises a main active component of VIB group in the periodic table of elements, an auxiliary agent of at least one element of La or Ce or an oxide thereof and at least one element of VIII B group noble metal or an oxide thereof, and a carrier selected from zirconia and/or titania modified alumina; pyridine infrared is adopted, and the mass ratio of L acid to B acid in the catalyst, m_B/m_LIn the range of 0 to 3, wherein m_LMeans the amount of L-acid in the catalyst, m_BRefers to the acid content of B.

2. The catalyst for n-butane dehydrogenation according to claim 1, wherein the active component mainly belonging to group VIB of the periodic Table of the elements is Cr and/or W element or its oxide, and the part of Cr and/or W element or its oxide is 5-20 parts by weight based on the n-butane catalyst; mass ratio of L acid to B acid in catalyst, m_B/m_LThe range is preferably 0 to 1.0, more preferably 0 to 0.8.

3. The catalyst for n-butane dehydrogenation according to claim 2, characterized in that the elements are selected from the group consisting of Cr and W in parts by weight of n-butane catalyst, wherein the weight ratio of Cr to W is: (0.1-9): 1.

4. the catalyst for n-butane dehydrogenation according to claim 1, wherein the amount of the La and/or Ce element or the oxide thereof is 0.01 to 3 parts by weight based on the weight of the n-butane catalyst.

5. The catalyst for n-butane dehydrogenation according to claim 1, wherein the catalyst is selected from the group consisting of group VIIIB elements of the periodic Table of the elements or oxides thereof in an amount of 0.01 to 5 parts by weight based on the weight of the n-butane catalyst, wherein the noble metal element of group VIIIB is selected from at least one of Pt, Pd, Ru and Rh.

6. The catalyst for n-butane dehydrogenation according to claim 1, wherein the catalyst support comprises zirconia and/or titania in an amount of 1 to 5 parts by weight based on the total parts by weight of the catalyst, wherein when zirconia and titania are added simultaneously, the ratio of zirconia to titania is (0.05 to 20): 1.

7. a catalyst carrier for n-butane dehydrogenation is characterized in that the carrier is modified and prepared by a hydrothermal method, and comprises the following steps:

a) soluble bauxite, zirconium salts and/or titanium salts;

b) adding alkali, and adjusting the pH value to 8-12 to enable the salt to form a colloid; carrying out hydrothermal reaction on the obtained colloidal sample for 6-72 hours at the temperature of 110-200 ℃;

c) the sample obtained in the step b) also comprises the steps of cooling, washing and filtering, and the obtained solid sample is dried and roasted to obtain the catalyst carrier.

8. The catalyst support for n-butane dehydrogenation according to claim 7, wherein:

1) the aluminum source is selected from one or more of boehmite, aluminum hydroxide, aluminum nitrate, aluminum chloride and aluminum sulfate, the zirconium salt is selected from zirconium nitrate and n-butyl zirconium, and the titanium salt is selected from titanium dioxide and tetrabutyl titanate; wherein the ratio of alumina to zirconia and/or titania, calculated as the final oxide form, ranges by weight: (10-100) 1:1, wherein the content of zirconium oxide and/or titanium oxide is 1-5 parts by weight; when the zirconium oxide and the titanium oxide are preferably added simultaneously, the ratio of the zirconium oxide to the titanium oxide is (0.05-20): 1.

2) the alkali is selected from one or more of sodium hydroxide, ammonia water and potassium hydroxide;

3) washing the sample obtained in the step 1) for 3-5 times, wherein Cl is^-、SO₄ ^-The ion content is less than 100 ppm; drying at 40-150 ℃ for 2-24 hours; the roasting temperature is 300-800 ℃, and the roasting time is 2-20 h.

9. A method for preparing a catalyst for n-butane dehydrogenation, characterized by comprising the steps of:

A) tabletting and screening the catalytic carrier to obtain a pretreated carrier I;

B) mixing a carrier I with soluble salt containing Cr and/or W, La and/or Ce and soluble salt of noble metal in a VIIIB group in required amount to obtain a mixture I, and adjusting the pH value of the mixture I with inorganic ammonia or inorganic ammonium salt solution within the range of 1-4 to obtain a mixture II;

C) and filtering and drying the mixture II to obtain the required n-butane dehydrogenation catalyst.

10. A method for dehydrogenating n-butane, which adopts the catalyst of any one of claims 1 to 9, and the reaction conditions are as follows: the reaction pressure is 0-1 MPa, the temperature is 500-620 ℃, and the mass space velocity is 0.1-8 h^-1(ii) a The reaction raw material is directly contacted with the catalyst for reaction to obtain n-butene.