A method for oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst.

Abstract

The application provides a method for oxidatively dehydrogenating low-carbon alkanes by using a BN-supported B2O3-coated Ni catalyst, wherein the BN-supported B2O3-coated Ni catalyst is applied to the reaction of oxidatively dehydrogenating low-carbon alkanes, and B2O3-coated nickel is generated by etching boron nitride by carbon dioxide at high temperature, so that the nickel as the core influences the electronic environment of the B2O3 coating layer, improves the chemical low-temperature activity, and makes the reaction of oxidatively dehydrogenating low-carbon alkanes realize efficient conversion of alkanes and high selectivity of alkenes at 400-500 DEG C.

Description

Technical Field

[0001] This invention belongs to the field of chemical catalysis technology, specifically relating to a method for the oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst. Background Technology

[0002] Low-carbon olefins are important raw materials for the industrial production of polymers (polyethylene, polypropylene, etc.), oxygen-containing compounds (ethylene glycol, acetaldehyde, propylene oxide, etc.), and intermediates in chemical processes (ethylbenzene, propionaldehyde, etc.). Converting low-carbon alkanes into olefins with the same carbon number through dehydrogenation reactions is an important method for the high-value utilization of alkanes and the production of olefin feedstocks. Catalytic dehydrogenation technology for alkanes has attracted much attention from industry and catalysis researchers due to its high atom economy and environmental friendliness. Compared with direct dehydrogenation of alkanes, oxidative dehydrogenation to produce olefins has advantages such as not being limited by reaction equilibrium, no coking, and lower reaction temperature.

[0003] Traditional metal oxides exhibit good catalytic activity, but they are prone to over-oxidation of olefins, leading to low olefin selectivity. In 2016, hexagonal boron nitride (h-BN) was first reported to exhibit high activity and propylene selectivity in the oxidative dehydrogenation of propane. As a novel non-metallic catalyst, h-BN demonstrates reaction characteristics significantly different from metal oxide catalysts, attracting widespread research. Further studies revealed that other boron-based catalysts possess similar catalytic properties, with very low CO2 content in the fully oxidized products. This opens a new pathway for the selective cleavage of CH bonds in the oxidative dehydrogenation of low-carbon alkanes. Since then, the design of boron-based catalysts, the exploration of their reaction mechanisms and structure-activity relationships, and further improvements in olefin selectivity and yield have become key research focuses.

[0004] However, boron-based catalysts exhibit poor activity at low temperatures, and reactions at high temperatures not only increase energy consumption but also lead to the deterioration of CO peroxidation products. x The increase in [amount] reduces selectivity. Simultaneously, during the oxidative dehydrogenation of alkanes, oxygen functionalization occurs on the surface of boron-based catalysts, and the resulting boron oxide species are considered to play a major catalytic role. Their participation in the reaction and regeneration requires high energy, which also leads to a higher reaction temperature. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for the oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst. Specifically, in the oxidative dehydrogenation reaction of low-carbon alkanes, a BN catalyst coated with B2O3 by adding metallic Ni and etching with CO2 is used. The electronic environment of the B2O3 coating layer is altered by the core Ni, enhancing its low-temperature chemical activity and achieving high alkane conversion and olefin selectivity in the reaction temperature range of 400–500°C.

[0006] A method for oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst includes:

[0007] An oxidative dehydrogenation reaction was carried out using a mixture of low-carbon alkanes and oxygen as the reaction gas and a Ni catalyst coated with B2O3 supported by BN.

[0008] The reaction temperature for oxidative dehydrogenation is 350–550 °C; the low-carbon alkane is a C2–C6 alkane.

[0009] The above-mentioned oxidative dehydrogenation reaction can be carried out under normal pressure.

[0010] Preferably, in the BN-supported B2O3-coated Ni catalyst, the nickel loading is 1–20 wt%. More preferably, it is 2–15 wt%. Even more preferably, it is 4–12 wt%.

[0011] Preferably, the oxidative dehydrogenation reaction is carried out in a tubular fixed-bed reactor, with a space velocity of 4000–60000 mL / g for the low-carbon alkanes. catal. -1 h -1 A further preferred value is 4000–15000 mL / g catal. -1 h -1 A further preferred value is 4000–12000 mL / g catal. -1 h -1 .

[0012] Preferably, the reaction temperature for the oxidative dehydrogenation is 400–500°C. More preferably, it is 400–460°C.

[0013] Preferably, the volume ratio of low-carbon alkanes to oxygen in the reaction gas is 1:(0.5-3). More preferably, the volume ratio of low-carbon alkanes to oxygen in the reaction gas is 1:(1-2).

[0014] Preferably, the reaction gas is a mixture of low-carbon alkanes and oxygen or a mixture of low-carbon alkanes and air.

[0015] In practical applications, an appropriate amount of nitrogen is usually added to the reaction gas. Preferably, the volume of low-carbon alkanes and oxygen accounts for 30 to 60% of the total volume of the reaction gas.

[0016] Preferably, the low-carbon alkane is one or more of ethane, propane, butane, pentane, and hexane.

[0017] In the oxidative dehydrogenation process, the BN-supported B2O3-coated Ni catalyst is heated to the reaction temperature in the reaction gas, and the product composition can be analyzed online by gas chromatography.

[0018] Preferably, the BN-supported B2O3-coated Ni catalyst is first sieved through a 40-60 mesh sieve before use, and then loaded into a quartz tube of a tubular fixed-bed reactor with an inner diameter of 8 mm. The loading amount of the BN-supported B2O3-coated Ni catalyst in the quartz tube is 10-200 mg.

[0019] Preferably, the BN-supported B2O3-coated Ni catalyst is prepared by the following steps:

[0020] (1) Disperse BN into a solvent by ultrasonication, add a nickel source and then ultrasonically treat it;

[0021] (2) The solvent was evaporated under heating and stirring after sonication, dried overnight, and reduced with hydrogen to obtain BN-loaded nickel sample;

[0022] (3) The BN-supported nickel sample was etched with CO2 at high temperature to obtain the BN-supported B2O3-coated Ni catalyst.

[0023] In step (3) above, CO2 is used to etch the BN-supported nickel sample at high temperature, generating B2O3 which migrates and coats the nickel, thereby obtaining a BN-supported B2O3-coated Ni catalyst. The hydrogen reduction mentioned in step (2) is carried out in a pure hydrogen stream.

[0024] As a further preferred embodiment, the solvent is one or more selected from ethanol, deionized water, acetone, and N,N-dimethylformamide (DMF). Ethanol or N,N-dimethylformamide (DMF) is even more preferred.

[0025] As a further preferred option, the nickel source is one or more of nickel nitrate, nickel sulfate, and nickel acetate.

[0026] As a further preferred option, BN is hexagonal boron nitride.

[0027] As a further preferred option, in step (1), the solution after adding the nickel source is ultrasonically treated for 20 to 80 minutes.

[0028] A further preferred time is 30–60 min.

[0029] As a further preferred option, in step (2), the heating temperature for evaporating the solvent is room temperature to 150°C.

[0030] A further preferred temperature is 60–130°C.

[0031] As a further preferred option, in step (2), the drying temperature is 50–150°C. Even more preferred is 80–140°C.

[0032] As a further preferred embodiment, in step (3), a CO2 / Ar or CO2 / N2 mixture is used for etching, wherein the volume concentration of CO2 is 10% to 90%. More preferably, it is 15% to 60%.

[0033] As a further preferred option, in step (3), the high-temperature etching process temperature is 400℃~1000℃. More preferably, it is 600~900℃.

[0034] As a further preferred option, the etching time in step (3) is 1 to 8 hours. Even more preferred is 2 to 6 hours.

[0035] As a further preferred option, in step (2), the temperature of the hydrogen reduction reaction is 400-600℃ and the reaction time is 2-8h.

[0036] As a further preferred option, the hydrogen flow rate during the hydrogen reduction process is 30–100 mL / min.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] This invention applies a BN-supported B2O3-coated Ni catalyst to the oxidative dehydrogenation reaction of low-carbon alkanes. It utilizes the B2O3-coated nickel produced by high-temperature etching of boron nitride with carbon dioxide. The nickel core affects the electronic environment of the B2O3 coating layer, enhancing its low-temperature chemical activity. This enables the oxidative dehydrogenation reaction of low-carbon alkanes to achieve efficient conversion of alkanes and high selectivity of olefins at 400–500°C. Attached Figure Description

[0039] Figure 1 X-ray diffraction patterns of BN-supported B2O3-coated Ni catalysts with different Ni contents (loadings); where a is a BN-supported B2O3-coated Ni catalyst with 2% nickel loading; b is a BN-supported B2O3-coated Ni catalyst with 4% nickel loading; c is a BN-supported B2O3-coated Ni catalyst with 6% nickel loading; and d is a BN-supported B2O3-coated Ni catalyst with 10% nickel loading.

[0040] Figure 2 Transmission electron microscopy image of the catalyst prepared by treating 4% Ni / BN in 20% CO2 / Ar at 800℃ for 2h;

[0041] Figure 3 To determine the activity and selectivity of propane oxidative dehydrogenation at different oxidative dehydrogenation reaction temperatures;

[0042] Figure 4 Activity and selectivity of propane oxidative dehydrogenation of catalysts prepared for different concentrations of CO2 / Ar;

[0043] Figure 5To evaluate the activity and selectivity of propane oxidative dehydrogenation of catalysts prepared at different etching temperatures;

[0044] Figure 6 The activity and selectivity of propane oxidative dehydrogenation of BN-supported B2O3-coated Ni catalysts with different nickel loadings were investigated. Detailed Implementation

[0045] To further illustrate the present invention, the following describes in detail the method for oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst, with reference to embodiments.

[0046] Example 1: Selection of Oxidative Dehydrogenation Reaction Temperature

[0047] 10 g of h-BN was ultrasonically dispersed in 100 ml of ethanol, and 2 g of Ni(NO3)·6H2O was added to the solution. The suspension was ultrasonically treated at room temperature for 30 min, then the solvent was evaporated under heating and stirring at 60 °C, dried at 80 °C overnight, and reduced at 500 °C for 2 h in a pure hydrogen stream at 30 ml / min. Subsequently, it was etched at 800 °C for 2 h with 20% CO2 / Ar at 50 ml / min to obtain the target catalyst (BN supported on B2O3 and coated with Ni), wherein the nickel loading was 4 wt%.

[0048] The transmission electron microscopy image of the prepared catalyst is shown below. Figure 2 As shown, by Figure 2 It can be seen that the diameter of the Ni metal particles is between 15 and 50 nm. The BN at the location of the Ni particles is etched to form pores, and the Ni core is coated with a layer of boron oxide (B2O3).

[0049] The catalyst (50 mg) prepared as described above was sieved through a 40-60 mesh sieve and then loaded into a fixed-bed tubular reactor (quartz tube inner diameter 8 mm). The propane oxidative dehydrogenation reaction was carried out using a mixture of propane, oxygen, and nitrogen (propane to oxygen volume ratio 1:1.5, with propane and oxygen accounting for 40% of the mixed gas volume) as the reaction gas. The reaction temperatures were 420℃, 440℃, 460℃, 480℃, 500℃, and 520℃, and the propane space velocity was 10000 mL / g. catal. -1 h -1 Simultaneously, the composition of the propane oxidative dehydrogenation reaction products at different reaction temperatures was analyzed online using gas chromatography, and the results are as follows: Figure 3 As shown.

[0050] Depend on Figure 3It can be seen that as the oxidative dehydrogenation reaction temperature increases, the propane conversion rate gradually increases, but the propylene selectivity gradually decreases. Overall, at reaction temperatures of 440℃ and 460℃, the propane conversion rate reaches over 20%, and the propylene selectivity reaches over 70%, demonstrating good performance.

[0051] Example 2: Selection of CO2 volume concentration in CO2 / Ar mixture:

[0052] BN-supported B2O3-coated Ni catalysts were prepared according to the preparation process in Example 1, wherein the volume concentrations of CO2 in the CO2 / Ar mixed gas were 10%, 20%, and 30%, respectively, and the amounts of other raw materials and process parameters were the same as in Example 1, resulting in the preparation of three catalysts.

[0053] Each catalyst (50 mg) prepared as described above was sieved through a 40-60 mesh sieve and then loaded into a fixed-bed tubular reactor (quartz tube inner diameter 8 mm). The propane oxidative dehydrogenation reaction was carried out using a mixture of propane, oxygen, and nitrogen (propane to oxygen volume ratio 1:1.5, propane and oxygen volumes accounting for 40% of the mixed gas volume) as the reaction gas. The reaction temperature was 440 °C, and the propane space velocity was 10000 mL / g. catal. -1 h -1 Simultaneously, the composition of propane oxidative dehydrogenation products at different reaction temperatures was analyzed online using gas chromatography, and the results are as follows: Figure 4 As shown.

[0054] Depend on Figure 4 It is observed that the selectivity for propylene in the oxidative dehydrogenation reaction increases with increasing CO2 concentration in the mixed gas, but the propane conversion rate gradually decreases, and the decrease is significant. This may be because the increased CO2 concentration leads to an increase in the thickness of the B2O3 coating layer outside the nickel. When the B2O3 coating layer thickness increases to a certain extent, the outermost B2O3 coating layer that can contact propane is less affected by the core nickel, thus negatively impacting the propane conversion rate. Therefore, considering both propane conversion rate and propylene selectivity, a CO2 concentration of 20% in the mixed gas is the optimal concentration.

[0055] Example 3: Selection of Etching Temperature

[0056] BN-supported B2O3-coated Ni catalysts were prepared according to the preparation process in Example 1, wherein the etching temperatures were 400℃, 600℃, and 800℃, and the amounts of other raw materials and process parameters were the same as in Example 1, resulting in three types of catalysts.

[0057] Each catalyst (50 mg) prepared as described above was sieved through a 40-60 mesh sieve and then loaded into a fixed-bed tubular reactor (quartz tube inner diameter 8 mm). The propane oxidative dehydrogenation reaction was carried out using a mixture of propane, oxygen, and nitrogen (propane to oxygen volume ratio 1:1.5, propane and oxygen volumes accounting for 40% of the mixed gas volume) as the reaction gas. The reaction temperature was 440 °C, and the propane space velocity was 10000 mL / g. catal. -1 h -1 Simultaneously, the composition of propane oxidative dehydrogenation products at different reaction temperatures was analyzed online using gas chromatography, and the results are as follows: Figure 5 As shown.

[0058] Depend on Figure 5 It can be seen that as the etching temperature increases, the propane conversion rate increases, but not significantly, while the propylene selectivity improves significantly. This may be because the B2O3 coating layer formed at lower etching temperatures is incomplete, resulting in higher selectivity for peroxidation products (CO2) and poorer catalytic performance. As the etching temperature increases, the B2O3 coating layer gradually becomes complete, improving catalytic performance and propylene selectivity. However, when the etching temperature is too high, the B2O3 coating layer becomes excessive, which in turn affects the propane conversion rate and reduces the catalytic performance of the catalyst. Therefore, an etching temperature of 800℃ provides the best catalysis for the propane oxidative dehydrogenation reaction, achieving a propane conversion rate of 23% and a total olefin selectivity of 80%.

[0059] Example 4: Selection of Nickel Loading

[0060] 10 g of h-BN was ultrasonically dispersed in 100 ml of ethanol, and Ni(NO3)·6H2O was added to the solution (1 g, 2 g, 3 g, and 5 g, respectively). The suspension was then ultrasonicated at room temperature for 30 min, and the solvent was evaporated under heating and stirring at 60 °C. The solution was dried at 80 °C overnight and reduced at 500 °C for 2 h in a pure hydrogen stream at 30 ml / min. Subsequently, the solution was etched at 800 °C for 2 h in a 20% CO2 / Ar stream at 50 ml / min to obtain target catalysts (BN supported on B2O3 and Ni coated) with different nickel loadings of 2 wt%, 4 wt%, 6 wt%, and 10 wt%.

[0061] The X-ray diffraction patterns of the four catalysts with different nickel loadings prepared above are shown in the figure. Figure 1 As shown, by Figure 1 It can be seen that the prepared catalysts all have characteristic diffraction peaks of BN and metallic Ni. With the increase of Ni content, the intensity of Ni characteristic diffraction peaks increases.

[0062] Each catalyst (50 mg) prepared as described above was sieved through a 40-60 mesh sieve and then loaded into a fixed-bed tubular reactor (quartz tube inner diameter 8 mm). The propane oxidative dehydrogenation reaction was carried out using a mixture of propane, oxygen, and nitrogen (propane to oxygen volume ratio 1:1.5, propane and oxygen volumes accounting for 40% of the mixed gas volume) as the reaction gas. The reaction temperature was 440 °C, and the propane space velocity was 10000 mL / g. catal. -1 h -1 Simultaneously, the composition of propane oxidative dehydrogenation products at different reaction temperatures was analyzed online using gas chromatography, and the results are as follows: Figure 6 As shown.

[0063] Depend on Figure 6 It can be seen that both propane conversion and propylene selectivity initially increase and then decrease with increasing nickel loading. The propane conversion is highest at a nickel loading of 4 wt%, reaching 23%, while the propylene selectivity is 60%. At a nickel loading of 6 wt%, the propylene selectivity is highest at 85%, and the total olefin selectivity reaches 90%, but the propane conversion is relatively low at 9%. Considering both propylene selectivity and propane conversion, a nickel loading of 4 wt% provides the best catalytic effect for the oxidative dehydrogenation of propane, representing the optimal nickel loading.

[0064] Example 5: Selection of gas space velocity for reaction

[0065] 10 g of h-BN was ultrasonically dispersed in 100 ml of ethanol, and 2 g of Ni(NO3)·6H2O was added to the solution. The suspension was then ultrasonically treated at room temperature for 30 min, and the solvent was evaporated under heating and stirring at 60 °C. The solution was dried at 80 °C overnight and then reduced at 500 °C for 2 h in a pure hydrogen stream at 30 ml / min. Subsequently, the solution was etched at 800 °C for 2 h with 20% CO2 / Ar at 50 ml / min to obtain the target catalyst (BN supported on B2O3 and coated with Ni).

[0066] The catalyst (50 mg) prepared as described above was sieved through a 40-60 mesh sieve and then loaded into a fixed-bed tubular reactor (quartz tube inner diameter 8 mm). The propane oxidative dehydrogenation reaction was carried out using a mixture of propane, oxygen, and nitrogen (propane to oxygen volume ratio 1:1.5, propane and oxygen volumes accounting for 40% of the mixed gas volume) as the reaction gas. The reaction temperature was 440℃, and the propane space velocity was 2000 mL / g. catal. -1 h -1 5000mL / g catal. -1 h -1 10000mL / g catal. -1 h -115000mL / g catal. -1 h -1 Simultaneously, gas chromatography was used to analyze the composition of propane oxidative dehydrogenation products at different reaction temperatures online.

[0067] The results show that when the propane space velocity is 2000 mL / g catal. -1 h -1 5000mL / g catal. -1 h -1 10000mL / g catal. -1 h -1 15000mL / g catal. -1 h -1 At the specified times, propane conversion rates were 86%, 45%, 23%, and 11%, respectively, while propylene selectivity was 22%, 57%, 80%, and 87%, respectively. Comparing propane conversion rate and propylene selectivity, it is considered that a space velocity of 10000 mL / g is optimal. catal. -1 h -1 It has the best performance at that time.

[0068] Example 6: Application in the oxidative dehydrogenation of different low-carbon alkanes

[0069] 10 g of h-BN was ultrasonically dispersed in 120 ml of N,N-dimethylformamide (DMF), and 3.5 g of NiSO4 was added to the solution. The suspension was ultrasonically treated at room temperature for 1 h, then the solvent was evaporated under heating and stirring at 130 °C, dried at 140 °C overnight, and reduced at 500 °C for 4 h in a pure hydrogen gas stream of 100 ml / min. Subsequently, it was etched at 700 °C for 6 h with 50% CO2 / Ar at a flow rate of 50 ml / min to obtain the target catalyst (BN supported on B2O3 and Ni coated), wherein the nickel loading was 11.7 wt%.

[0070] Each catalyst (50 mg) prepared as described above was sieved through a 40-60 mesh sieve and then loaded into a fixed-bed tubular reactor (quartz tube inner diameter 8 mm). A mixture of low-carbon alkanes, oxygen, and nitrogen (low-carbon alkanes to oxygen volume ratio 1:1.5, with low-carbon alkanes and oxygen accounting for 40% of the mixed gas volume) was used as the reaction gas for propane oxidative dehydrogenation. The low-carbon alkanes included ethane, butane, pentane, and hexane. Simultaneously, gas chromatography was used to analyze the composition of the propane oxidative dehydrogenation products at different reaction temperatures online.

[0071] The reaction conditions and analytical results are as follows:

[0072] In the oxidative dehydrogenation of ethane, this catalyst was used at a temperature of 450 °C and a gas space velocity of 7000 mL / g. catal. - 1 h -1 At that time, the ethane conversion rate was 28%, and the ethylene selectivity was 87%.

[0073] In the oxidative dehydrogenation of butane, this catalyst was used at a temperature of 440 °C and a gas space velocity of 8000 mL / g. catal. - 1 h -1 At that time, the butane conversion rate was 23%, and the butene selectivity was 78%.

[0074] In the oxidative dehydrogenation of pentane, this catalyst was used at a temperature of 430 °C and a gas space velocity of 5000 mL / g. catal. - 1 h -1 At that time, the pentane conversion rate was 26%, and the pentene selectivity was 73%.

[0075] In the oxidative dehydrogenation of hexane, this catalyst was used at a temperature of 450 °C and a gas space velocity of 4000 mL / g. catal. - 1 h -1 At that time, the hexane conversion rate was 32%, and the hexene selectivity was 69%.

Claims

1. A method for the oxidative dehydrogenation of lower alkanes using a BN-supported B2O3-coated Ni catalyst, characterized in that, include: An oxidative dehydrogenation reaction was carried out using a mixture of low-carbon alkanes and oxygen as the reaction gas and a Ni catalyst coated with B2O3 supported by BN. The reaction temperature for oxidative dehydrogenation is 350~550℃; the low-carbon alkane is a C2~C6 alkane. The BN-supported B2O3-coated Ni catalyst was prepared by the following steps: (1) Disperse BN into a solvent by ultrasonication, add a nickel source, and then ultrasonically treat; (2) The solvent was evaporated by heating and stirring after sonication, dried overnight, and reduced with hydrogen to obtain BN-loaded nickel sample; (3) The BN-supported nickel sample was etched with CO2 at high temperature to obtain the BN-supported B2O3-coated Ni catalyst.

2. The method according to claim 1, wherein the catalyst is a BN-supported B2O3-coated Ni catalyst. In the BN-supported B2O3-coated Ni catalyst, the nickel loading is 1~20wt%. 3.The method for the oxidative dehydrogenation of light alkanes using a BN-supported B2O3-coated Ni catalyst according to claim 1, characterized in that, The oxidative dehydrogenation reaction is carried out in a tubular fixed bed reactor, wherein the space velocity of the reaction gas is 4000 to 60000 mL / g catal. -1 h -1 .

4. The method for oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst according to claim 1, characterized in that, The reaction temperature for the oxidative dehydrogenation is 400~500℃.

5. The method for oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst according to claim 1, characterized in that, The low-carbon alkane is one or more of ethane, propane, butane, pentane, and hexane.

6. The method for oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst according to claim 1, characterized in that, The volume ratio of low-carbon alkanes to oxygen in the reaction gas is 1:(0.5~3).

7. The method for oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst according to claim 1, characterized in that, The solvent is one or more of ethanol, deionized water, acetone, and N,N-dimethylformamide; The nickel source is one or more of nickel nitrate, nickel sulfate, and nickel acetate.

8. The method for oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst according to claim 1, characterized in that, In step (3), etching is performed using a CO2 / Ar or CO2 / N2 mixture, wherein the volume concentration of CO2 is 10% to 90%.

9. The method for oxidative dehydrogenation of low-carbon alkanes using a BN-supported B2O3-coated Ni catalyst according to claim 1, characterized in that, In step (3), the high-temperature etching process temperature is 400 ℃ ~ 1000 ℃.

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