CN113083284B

CN113083284B - Mo-V-Te-Sb-Nb-O catalyst, and preparation method and application thereof

Info

Publication number: CN113083284B
Application number: CN202110397045.7A
Authority: CN
Inventors: 王成光; 黄庆
Original assignee: Ningbo Haoxiang New Material Technology Co ltd
Current assignee: Ningbo Haoxiang New Material Technology Co ltd
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2022-03-08
Anticipated expiration: 2041-04-13
Also published as: CN113083284A

Abstract

The invention discloses a Mo-V-Te-Sb-Nb-O catalyst, and a preparation method and application thereof. The preparation method comprises the following steps: depositing an antimony source on metal tellurium particles serving as a tellurium source, reacting the metal tellurium particles with a molybdenum source, a vanadium source and a niobium source in a solvent to obtain a catalyst precursor, and drying and roasting the catalyst precursor. The Mo-V-Te-Sb-Nb-O catalyst provided by the invention has excellent stability and catalytic activity, and can remarkably improve the selectivity and yield of acrylic acid when being applied to the reaction of preparing acrylic acid from propane.

Description

Mo-V-Te-Sb-Nb-O catalyst, and preparation method and application thereof

Technical Field

The invention relates to a metal oxide catalyst, in particular to a Mo-V-Te-Sb-Nb-O catalyst, a preparation method thereof and application thereof in a process for preparing acrylic acid from propane, belonging to the technical field of catalysis.

Background

Acrylic acid is an important raw material for petrochemical, light industry and medical production, can be used for producing super absorbent resins, synthetic resins, flocculants and the like, and still expands the application range. Generally, propylene and oxygen are catalytically oxidized at about 400 ℃ in the presence of a Mo-Bi catalyst to produce acrolein, and then acrolein and oxygen are catalytically oxidized at about 300 ℃ in the presence of a Mo-V catalyst to produce acrylic acid.

In contrast, propane is a cheaper starting material than propylene, and there are many publications disclosing the possibility of producing acrylic acid by the one-step oxidation of propane. And with the exploitation and popularization of shale gas, the price difference between propane and propylene will be further increased. Many catalysts for producing acrylic acid from propane have been disclosed, for example, V-P-O-based, Mo-Te-V-Nb-based, Mo-Sb-V-Nb-based catalysts, etc. Among them, the system having the highest performance level and closest to practical use is the Mo-Te-V-Nb system. However, even in the Mo-Te-V-Nb system, there are still many problems in realizing industrialization of propane to produce acrylic acid.

It has been pointed out by researchers that the performance of Mo-Te-V-Nb based catalysts gradually decreases with the passage of reaction time. One reason for this is that Te element gradually volatilizes under the reaction conditions to cause the catalyst activity to change. The use of Sb having a low volatility in place of Te has been a solution to this problem, but Mo-Sb-V-Nb series have a lower performance than Mo-Te-V-Nb series.

Disclosure of Invention

The invention mainly aims to provide a Mo-V-Te-Sb-Nb-O catalyst, a preparation method and application thereof, so as to overcome the defects in the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:

the embodiment of the invention provides a preparation method of a Mo-V-Te-Sb-Nb-O catalyst, which comprises the following steps:

depositing at least part of antimony source on tellurium metal particles serving as a tellurium source to obtain a first raw material;

reacting the first raw material with a molybdenum source, a vanadium source and a niobium source in a solvent to obtain a catalyst precursor;

and drying and roasting the catalyst precursor to prepare the Mo-V-Te-Sb-Nb-O catalyst.

In some embodiments, the firing treatment includes a first stage firing and a second stage firing, wherein the first stage firing is performed in the presence of oxygen and the second stage firing is performed under low oxygen conditions.

The embodiment of the invention also provides a Mo-V-Te-Sb-Nb-O catalyst prepared by any one method.

The embodiment of the invention also provides a Mo-V-Te-Sb-Nb-O catalyst with a chemical formula of MoV_jTe_kSb_lNb_mO_nWherein j is 0.1 to 1.5, k is 0.01 to 1.5, k/j is 0.3 to 1.5, l is 0 to 0.1, m is 0.01 to 0.3, and n is a value determined by the oxidation state of Mo, V, Te, Sb, and Nb.

The embodiment of the invention also provides the application of the Mo-V-Te-Sb-Nb-O catalyst in the reaction of preparing acrylic acid by using propane.

Compared with the prior art, the Mo-V-Te-Sb-Nb-O catalyst provided by the embodiment of the invention has excellent stability and catalytic activity, and can obviously improve the selectivity and yield of acrylic acid when being applied to the reaction of preparing acrylic acid from propane.

Detailed Description

The invention will be more fully understood upon reading the following detailed description. Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed embodiment.

Unless specifically stated otherwise, use of the terms "comprising", "including", "having" or "having" is generally to be understood as open-ended and not limiting.

It should be understood that the order of steps or the order in which particular actions are performed is not critical, so long as the teachings of the invention remain operable. Further, two or more steps or actions may be performed simultaneously.

The preparation method of the Mo-V-Te-Sb-Nb-O catalyst provided by the embodiment of the invention comprises the following steps:

In some embodiments, the method of making comprises:

the first raw material is reacted with a molybdenum source, a vanadium source and a niobium source in a solvent to obtain a slurry containing a catalyst precursor.

Further, the preparation method specifically comprises the following steps: adding a precursor of the antimony source into the water-containing slurry of the tellurium source to perform a precipitation reaction, depositing at least part of the antimony source on the tellurium metal particles, obtaining a first mixed slurry containing the antimony source and the tellurium metal, and then separating to obtain a mixture of the tellurium metal and the antimony source, namely the first raw material.

Further, the preparation method specifically comprises the following steps: after the first mixed slurry is obtained, the clear liquid is removed to obtain a mixture of the metal tellurium and the antimony source. Wherein the aforementioned clear liquid may be removed by means known in the art, such as by standing and pouring.

Compared with tellurium element, antimony element adopted in the embodiment of the invention has low price and small volatility at high temperature, and has more advantages as a catalyst raw material.

Further, the precursor of the antimony source includes, but is not limited to, antimony trichloride or antimony pentachloride, etc., which become antimony hydroxide precipitate after being added to the aqueous slurry of the tellurium source. Antimony hydroxide may be used as an antimony source.

In some embodiments, the tellurium metal particles are needle-shaped, have a length of 300nm to 900nm, and have a diameter of 30nm to 200 nm.

Further, the preparation method comprises the following steps: and reducing the tellurium oxide by using a reducing agent to form the tellurium source, wherein the standard oxidation-reduction potential of the reducing agent is below 0.4V. The conditions required for this reduction reaction are well known to those skilled in the art. Wherein, by adopting the needle-shaped metal tellurium particles as the tellurium source, the harmful reductive raw materials are easy to be washed, separated and removed.

Wherein the tellurium oxide includes but is not limited to TeO₂。

Wherein the reducing agent includes, but is not limited to, hydrazine.

In some embodiments, the method of making further comprises: and mixing the first raw material with an aqueous solution of a molybdenum source and a vanadium source to form a second mixed slurry, heating, and adding a niobium source to react to obtain a slurry containing a catalyst precursor. Further, the heating temperature is 40-100 ℃. The heating time is 0 to 3 hours, preferably 0 to 1 hour.

Wherein a complex as a catalyst precursor can be formed by adding a niobium source to the heated second mixed slurry.

Further, as the molybdenum source, the vanadium source, the tellurium source, and the niobium source, there may be mentioned molybdate (e.g. ammonium tetramolybdate), vanadate (e.g. ammonium metavanadate), metal tellurium, tellurium dioxide or telluric acid, niobic acid or niobic acid hydrate, and niobium pentoxide, which are commonly used in the art, and the specific kind of the selected substance is not limited.

Further, the atomic ratio of the vanadium source, the tellurium source, the antimony source and the niobium source relative to the molybdenum source is 0.1-1.5, 0.01-1.5, 0-0.1 and 0.01-0.5 respectively, and the atomic ratio of the tellurium source relative to the vanadium source is 0.3-1.5.

Preferably, the atomic ratio of the vanadium source, the tellurium source, the antimony source and the niobium source relative to the molybdenum source is 0.1-0.4, 0.01-0.3, 0-0.07 and 0.01-0.3 respectively, and the atomic ratio of the tellurium source relative to the vanadium source is 0.3-0.8.

In some embodiments, the preparation method specifically comprises: and adding the niobium source directly into the heated second mixed slurry to perform a reaction, thereby obtaining a slurry containing a catalyst precursor.

In some embodiments, the preparation method specifically comprises: and mixing the niobium source and hydrogen peroxide, and then adding the mixture into the heated second mixed slurry for reaction, thereby obtaining the slurry containing the catalyst precursor.

Further, the molar ratio of the hydrogen peroxide to the niobium source is 0.5 or less, preferably 0.3 or less.

In some embodiments, the preparation method specifically comprises: and directly drying and roasting the slurry containing the catalyst precursor.

In some embodiments, the preparation method specifically comprises: and adding ammonia water and/or ammonium nitrate into the slurry containing the catalyst precursor, and then carrying out drying and roasting treatment.

Further, the molar ratio of the ammonia water to the molybdenum source is 0.02 or more, preferably 0.04 or more.

Further, the molar ratio of the ammonium nitrate to the molybdenum source is 0.2 or more, preferably 0.4 or more.

Further, the drying process may be performed by natural air drying or airing, oven drying, vacuum drying, freeze drying, spray drying, etc. which are well known in the art, and is not limited thereto. Preferably, the drying treatment is spray drying, so as to facilitate continuous operation.

In some embodiments, the firing process includes a first stage firing and a second stage firing.

Further, the first-stage roasting is carried out in the presence of oxygen, the roasting temperature is 250-380 ℃, the roasting time is 280-360 ℃, and the roasting time is 3-30 minutes, preferably 5-15 minutes.

Further, the second-stage roasting is carried out under a low-oxygen condition, the roasting temperature is 480-640 degrees, preferably above 550 ℃, and the roasting time is 1-5 hours.

Further, the low oxygen condition includes an atmosphere formed by nitrogen and/or inert gas.

Wherein the first and second stage firings may be performed in a variety of equipment well known in the art.

In some more specific embodiments, the preparation method may comprise the following steps:

(1) continuously stirring the aqueous slurry of the metal tellurium, and dripping a solution of a precursor of an antimony source for precipitation reaction to obtain a mixture slurry of the antimony source and the metal tellurium;

(2) separating and removing part of clear liquid in the mixture slurry of the antimony source and the tellurium metal to obtain a tellurium and antimony source mixture, and adding the tellurium and antimony source mixture into an aqueous solution of a molybdenum source and a vanadium source for heating;

(3) adding a niobium source into the mixed liquid slurry obtained in the step (2) to form a complex, namely a catalyst precursor;

(4) spray drying the catalyst precursor to obtain micro powder particles

(5) Carrying out primary roasting on the micro powder particles obtained in the step (4) in an aerobic atmosphere;

(6) carrying out secondary roasting on the micro powder particles treated in the step (5) under the conditions of low oxygen atmosphere and temperature of more than 550 ℃, and finally obtaining the MoV with the chemical general formula_jTe_kSb_lNb_mO_nThe catalyst of (1).

Wherein the aqueous slurry of tellurium metal in step (1) may be prepared by oxidizing a high-valence tellurium oxide (e.g., TeO)₂) Reducing with a reducing agent (such as hydrazine) to obtain the final product, wherein the tellurium metal is needle-shaped particles.

In some embodiments, the preparation method may further include some post-treatment steps, which may be performed in a manner well known in the art. For example, the calcination treatment may be performed by pressing the obtained catalyst to form a compact and then crushing the compact into catalyst particles.

More specifically, after the calcination treatment is completed, the obtained catalyst may be subjected to ingot forming under high pressure into a cylindrical shape, followed by crushing and use.

Embodiments of the present invention provide Mo-V-Te-Sb-Nb-O catalysts prepared by any of the foregoing methods.

The embodiment of the invention provides a Mo-V-Te-Sb-Nb-O catalyst, the chemical formula of which is MoV_jTe_kSb_lNb_mO_nWherein j is 0.1 to 1.5, k is 0.01 to 1.5, k/j is 0.3 to 1.5, l is 0 to 0.1, m is 0.01 to 0.3, and n is a value determined by the oxidation state of Mo, V, Te, Sb, and Nb.

The embodiment of the invention provides application of the Mo-V-Te-Sb-Nb-O catalyst in the reaction of preparing acrylic acid by using propane.

The embodiment of the invention provides a method for preparing acrylic acid from propane, which comprises the following steps: in the presence of the Mo-V-Te-Sb-Nb-O catalyst, propane is oxidized to form acrylic acid.

In the above embodiment of the present invention, the performance of the Mo-Te-Sb-V-Nb based catalyst is significantly improved by improving the preparation process of the Mo-Te-Sb-V-Nb based catalyst, for example, by using a slurry of a metal tellurium source as a carrier to uniformly deposit an antimony source as a raw material to prepare the catalyst.

The technical solution of the present invention will be described in more detail with reference to several embodiments as follows. It is to be noted that, unless otherwise specified, the raw materials, chemical reagents, equipment and the like used in the following examples may be obtained by means of commercial purchase and the like, and the operations such as washing, drying, stirring, spray drying and the like may be performed in accordance with a manner known in the art.

Example 1

A Mo-Te-Sb-V-Nb-based catalyst of this example was prepared by the following steps 1) to 3):

1) mixing and drying: adding 370.8g of ammonium tetramolybdate and 65.4g of ammonium metavanadate into 900g of distilled water, stirring and dissolving at 80 ℃, adding the solution A and 576g of ammonia water with the concentration of 2.0 wt%, continuing stirring, maintaining stirring when the temperature of a reaction system is reduced to 50 ℃, adding the solution B to obtain a viscous precipitate, continuing stirring for 5 minutes, adding 960g of ammonium nitrate into the reaction system, continuing stirring, and finally spray-drying the obtained slurry into powder.

Wherein, the liquid A and the liquid B can be prepared by the following method which comprises the following steps:

44.8g of tellurium dioxide, 34.5g of hydrazine and 800g of distilled water are mixed, stirred at 80 ℃ for 4 hours, heated and reduced to obtain slurry containing metal tellurium needle-shaped particles (needles with the average length of 0.3 mu m and the average diameter of 0.1 mu m), 13.7g of antimony trichloride is added under stirring, and the mixture is washed with distilled water to obtain slurry, namely solution A.

Adding 167g of oxalic acid (dihydrate) and 60.1g of niobic acid hydrate (the content of niobic acid is 72.2 wt%) into 1719g of distilled water, dissolving at 80 ℃, cooling, and then adding 17.4g of 30 wt% hydrogen peroxide to obtain solution B.

2) First-stage roasting: roasting the powder finally obtained in the step 1) in an oxygen-containing atmosphere, wherein the roasting temperature is set to be 300 ℃, and the roasting time is 12 minutes.

3) And (3) secondary roasting: and roasting the particles obtained from the first-stage roasted product at 600 ℃ for 1.5 hours in a nitrogen atmosphere to obtain a metal oxide crystallization active phase, namely the target catalyst. Analyzing the atomic ratio of the target catalyst by using fluorescent X-rays, and determining that the composition of the target catalyst is as follows: Mo/V/Te/Sb/Nb ═ 1.0/0.28/0.14/0.03/0.16 (molar ratio).

Evaluation of reaction for producing acrylic acid from propane:

the aforementioned objects are achievedAfter the standard catalyst is shaped into a cylinder, crushing and screening the standard catalyst into particles with the diameter of 0.5-1.0 mm, and filling the particles into a reactor with the inner diameter of 10 mm. According to the raw material composition of propane/oxygen/steam/nitrogen gas as 1/2.3/3.3/8.7 (mole ratio), the SV is 2400h at 380 DEG C^-1Under the conditions, the conversion of propane and the yield of acrylic acid were evaluated. Then, under the same reactant composition, the temperature was raised to 400 ℃, and after the reaction was continued for 1000 hours, the temperature was lowered to 380 ℃, and then evaluation was performed. The change before and after the continuation of the reaction is shown in Table 1, and the yield of acrylic acid was changed from 41.0% to 40.4%.

Comparative example 1

The preparation method of the Mo-Te-Sb-V-Nb catalyst provided by the comparison example is basically the same as that of the example 1, and the difference is that: the operation of adding antimony trichloride into the slurry containing the needle-shaped tellurium metal particles is omitted.

Further, this comparative example was evaluated for the performance of the catalyst in the same manner as in example 1. As a result, as shown in Table 1, it was found that the yield of acrylic acid was changed from 41.4% to 35.7% before and after the reaction continued for 1000 hours by using the catalyst product of this comparative example.

Comparative example 2

The preparation method of the Mo-Te-Sb-V-Nb catalyst provided by the comparison example is basically the same as that of the example 1, and the difference is that:

the step of washing the liquid slurry of the needle-shaped tellurium particles and antimony trichloride to form the solution A is omitted, and the liquid slurry containing the needle-shaped tellurium particles and antimony trichloride are independently added into the mixed solution of ammonium tetramolybdate and ammonium metavanadate.

Further, this comparative example was evaluated for the performance of the catalyst in the same manner as in example 1. The results are shown in Table 1.

TABLE 1

Example 2 the process for preparing a Mo-Te-Sb-V-Nb based catalyst of this example is essentially the same as in example 1, except that:

in the step 1), the atomic ratios of the vanadium source, the tellurium source, the antimony source and the niobium source relative to the molybdenum source are respectively 0.1, 0.01, 0.07 and 0.3, and the atomic ratio of the tellurium source relative to the vanadium source is 0.3.

In the step 1), ammonium tetramolybdate and ammonium metavanadate are stirred and dissolved in distilled water at 40 ℃, then liquid A and 576g of ammonia water with the concentration of 2.0 wt% are added, stirring is continued, the temperature of a reaction system is maintained at 40 ℃, liquid B is added to obtain viscous precipitates, ammonium nitrate (the molar ratio of ammonium nitrate to a molybdenum source is 0.4) is added into the reaction system after stirring is continued, and finally the obtained liquid slurry is sprayed and dried into powder.

In the step 1), the preparation method of the solution B does not adopt hydrogen peroxide.

In the step 2), the roasting temperature of the first-stage roasting is 280 ℃, and the roasting time is 15 minutes.

In the step 3), the second-stage roasting is carried out in a nitrogen atmosphere, the roasting temperature is 570 ℃, and the roasting time is 5 hours.

Example 3 a Mo-Te-Sb-V-Nb-based catalyst of this example was prepared by a process substantially the same as example 1, except that:

in the step 1), the atomic ratios of the vanadium source, the tellurium source, the antimony source and the niobium source relative to the molybdenum source are respectively 0.4, 0.3, 0.01 and 0.01, and the atomic ratio of the tellurium source relative to the vanadium source is 0.8.

In the step 1), ammonium tetramolybdate and ammonium metavanadate are stirred and dissolved in distilled water at 100 ℃, then liquid A and 576g of ammonia water with the concentration of 2.0 wt% are added, stirring is continued, when the temperature of a reaction system is reduced to 50 ℃, liquid B is added to obtain a viscous precipitate, ammonium nitrate (the molar ratio of ammonium nitrate to a molybdenum source is 0.2) is added into the reaction system after continuous stirring, stirring is continued, and finally the obtained liquid slurry is sprayed and dried into powder.

In the step 1), in the preparation method of the solution B, the molar ratio of hydrogen peroxide to the niobium source is 0.3.

In the step 2), the roasting temperature of the first-stage roasting is 360 ℃, and the roasting time is 5 minutes.

In the step 3), the second-stage roasting is carried out in an inert atmosphere, the roasting temperature is 640 ℃, and the roasting time is 1 hour.

Example 4 a Mo-Te-Sb-V-Nb-based catalyst of this example was prepared by a process substantially the same as example 1, except that:

in the step 1), the atomic ratios of the vanadium source, the tellurium source, the antimony source and the niobium source relative to the molybdenum source are respectively 1.5, 0.1 and 0.5, and the atomic ratio of the tellurium source relative to the vanadium source is 1.5.

In the step 1), adding ammonium tetramolybdate and ammonium metavanadate into distilled water, stirring and dissolving at 80 ℃, adding the solution A and ammonia water, continuing stirring, maintaining stirring when the temperature of a reaction system is reduced to 50 ℃, adding the solution B to obtain a viscous precipitate, continuously stirring for 5 minutes, then adding ammonia water (the molar ratio of the ammonia water to the molybdenum source is 0.04) into the reaction system, continuing stirring, and finally spray-drying the obtained slurry into powder.

In the step 2), the roasting temperature of the first-stage roasting is 380 ℃, and the roasting time is 3 minutes.

In the step 3), the second-stage roasting is carried out in a nitrogen atmosphere, the roasting temperature is 480 ℃, and the roasting time is 5 hours.

The performance of the catalysts obtained in examples 2 to 4 was evaluated by referring to the manner of example 1, and the results showed that the performance of the catalysts obtained in examples 2 to 3 was superior to that of the catalyst obtained in example 4 and substantially equivalent to that of the catalyst obtained in example 1.

It should be noted that, in this document, unless otherwise explicitly specified or limited, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

It should be understood that the foregoing is only illustrative of the present invention and that numerous changes and modifications may be made by those skilled in the art without departing from the principles of the invention and these are to be considered within the scope of the invention.

Claims

1. A preparation method of a Mo-V-Te-Sb-Nb-O catalyst is characterized by comprising the following steps:

providing metal tellurium particles as a tellurium source, wherein the metal tellurium particles are needle-shaped, the length of the metal tellurium particles is 300-900 nm, and the diameter of the metal tellurium particles is 30-200 nm;

adding a precursor of an antimony source into the aqueous slurry of the tellurium source to perform a precipitation reaction, depositing at least part of the antimony source on the tellurium metal particles, obtaining a first mixed slurry containing the antimony source and the tellurium metal, and then separating to obtain a mixture of the tellurium metal and the antimony source, namely obtaining a first raw material;

mixing the first raw material with an aqueous solution of a molybdenum source and a vanadium source to form a second mixed slurry, heating to above 40 ℃, and adding a niobium source to react to obtain a slurry containing a catalyst precursor;

drying and roasting the catalyst precursor to prepare the Mo-V-Te-Sb-Nb-O catalyst, wherein the roasting treatment comprises primary roasting and secondary roasting, the primary roasting is carried out in the presence of oxygen, the roasting temperature is 250-380 ℃, the roasting time is 3-30 minutes, the secondary roasting is carried out in the presence of low oxygen, the roasting temperature is 480-640 ℃, and the roasting time is 1-5 hours;

the atomic ratio of the vanadium source, the tellurium source, the antimony source and the niobium source relative to the molybdenum source is 0.1-1.5, 0.01-1.5, 0-0.1 and 0.01-0.5 respectively, the atomic ratio of the tellurium source relative to the vanadium source is 0.3-1.5, and the dosage of the antimony source is not 0.

2. The method according to claim 1, comprising: after the first mixed slurry is obtained, the clear liquid is removed to obtain a mixture of the metal tellurium and the antimony source.

3. The production method according to claim 1, characterized by comprising: and reducing the tellurium oxide by using a reducing agent to form the tellurium source, wherein the standard oxidation-reduction potential of the reducing agent is below 0.4V.

4. The production method according to claim 3, characterized in that: the tellurium oxide comprises TeO₂The reducing agent comprises hydrazine.

5. The method of claim 1, further comprising: mixing the first raw material with an aqueous solution of a molybdenum source and a vanadium source to form a second mixed slurry, and heating to 40-100 ℃.

6. The production method according to claim 1 or 5, characterized in that: the heating time is more than 0 and less than or equal to 3 hours.

7. The method of claim 6, wherein: the heating time is more than 0 and less than or equal to 1 hour.

8. The method according to claim 1, comprising: and directly drying and roasting the slurry containing the catalyst precursor.

9. The method of claim 1, wherein: adding ammonia water and/or ammonium nitrate into the slurry containing the catalyst precursor, and then drying and roasting; the molar ratio of the ammonia water to the molybdenum source is 0.02 or more, and the molar ratio of the ammonium nitrate to the molybdenum source is 0.2 or more.

10. The method of claim 9, wherein: the molar ratio of the ammonia water to the molybdenum source is 0.04 or more, and the molar ratio of the ammonium nitrate to the molybdenum source is 0.4 or more.

11. The method of claim 1, 8 or 9, wherein: the drying process comprises spray drying.

12. The method of claim 1, wherein: the roasting temperature of the first-stage roasting is 280-360 ℃, and the roasting time is 5-15 minutes.

13. The method of claim 1, wherein: the roasting temperature of the second-stage roasting is 550-640 ℃.

14. The method of claim 1, wherein: the low oxygen conditions include an atmosphere formed by nitrogen and/or inert gas.

15. A Mo-V-Te-Sb-Nb-O catalyst of the formula MoV prepared by the process of any one of claims 1 to 14_jTe_kSb_lNb_mO_nWherein j is 0.1 to 1.5, k is 0.01 to 1.5, k/j =0.3 to 1.5, l is 0 to 0.1, m is 0.01 to 0.3, and n is a value determined by the oxidation state of Mo, V, Te, Sb, and Nb, wherein the Sb content is not 0.

16. Use of the Mo-V-Te-Sb-Nb-O catalyst according to claim 15 in the reaction of propane to acrylic acid.