Novel sacrificial catalyst for medium-high temperature H2S removal and short-chain alkane catalytic oxidation as well as preparation method and application of novel sacrificial catalyst

Abstract

The invention discloses a novel sacrificial catalyst for medium-high temperature H2S removal and short-chain alkane catalytic oxidation as well as a preparation method and application of the novel sacrificial catalyst. The catalyst is prepared by a hydrothermal method and comprises the following specific steps: dissolving manganese acetate in deionized water, and sequentially adding concentrated nitric acid, potassium permanganate and cerous nitrate according to a certain proportion; after uniformly mixing, transferring the precursor solution into a hydrothermal kettle, and carrying out crystallization reaction; and washing, drying, grinding and calcining the obtained precipitate to finally obtain the composite metal oxide catalyst. According to the present invention, under the medium-high temperature environment of 250-500 DEG C, the complete removal of H2S can be achieved, the H2S is not released in the form of SO2, and the poisoning effect of H2S on the post-catalyst is delayed; meanwhile, the sacrificial agent also has a short-chain alkane catalytic oxidation function, and shows good catalytic activity to ethane.

Description

Technical Field

[0001] This invention belongs to the field of air pollution control technology, specifically relating to a novel sacrificial catalyst for medium- and high-temperature H2S removal and short-chain alkane catalytic oxidation, its preparation method, and its application. Background Technology

[0002] Among the many causes of pollution, volatile organic compounds (VOCs) are important precursors to the formation of particulate matter, ozone and other atmospheric compound pollutants. They not only seriously hinder the sustainable development of society and economy, but also pose a dual threat to human health and the ecological environment.

[0003] Catalytic oxidation technology has demonstrated significant advantages in treating VOCs, particularly in the petrochemical and organic chemical industries, where it has become one of the most effective treatment methods. This technology, through the action of a catalyst, can completely oxidize VOCs into non-toxic or low-toxic substances such as CO2 and H2O at relatively low temperatures, thus achieving effective purification of harmful gases. However, in the modern coal chemical industry, the emission characteristics of VOCs present new challenges to the application of catalytic oxidation technology. The VOCs emitted by the coal chemical industry are diverse and complex in composition, with short-chain alkanes, represented by ethane, accounting for a large proportion of emissions at various stages. Furthermore, the waste gas contains not only short-chain hydrocarbons but also sulfides such as H2S; even at ppm levels, these can severely impact catalyst performance, leading to catalyst poisoning and reducing its catalytic activity and lifespan. These issues are significant factors hindering the widespread application of related reaction catalysts in industry.

[0004] To address this, researchers have developed various desulfurizing agents aimed at effectively removing sulfur-containing gases such as H2S, thereby extending the lifespan of downstream catalysts. For example, patent CN115814583A discloses a medium-to-high temperature desulfurization composite adsorbent. This composite adsorbent uses attapulgite or attapulgite-modified materials as a carrier and metal oxides supported on the carrier as the active ingredient, enabling the removal of H2S at a high temperature of 650℃. However, this adsorbent, as well as most mainstream catalytic materials currently on the market, require a reducing atmosphere such as H2 to perform desulfurization reactions. Materials that can stably and efficiently remove sulfur-containing gases such as H2S under medium-to-high temperature oxidizing environments are relatively scarce. Furthermore, current research on desulfurizing agents mainly focuses on the single treatment of sulfur-containing gases, lacking multifunctional composite catalysts that can simultaneously and efficiently remove other VOCs pollutants. Summary of the Invention

[0005] To overcome the problems of existing technologies, this invention provides a novel sacrificial catalyst for the removal of H2S at medium and high temperatures, combined with the catalytic oxidation of short-chain alkanes, along with its preparation method and applications. This catalyst is prepared via a mild hydrothermal method, achieving H2S adsorption and irreversible oxidation through surface sulfur trapping sites, forming stable sulfate species. It exhibits good H2S removal efficiency and ethane conversion rate during simultaneous removal of H2S and ethane at 250-500℃, showing promising prospects for industrial applications.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing a novel sacrificial catalyst for the removal of H2S at medium and high temperatures, which also serves as a catalyst for the catalytic oxidation of short-chain alkanes, specifically includes the following steps:

[0008] (1) Preparation of precursor solution: Weigh an appropriate amount of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in deionized water. Stir magnetically until completely clear, then add concentrated nitric acid (mass concentration of 65%-68%) dropwise to form a homogeneous manganese salt solution. Weigh potassium permanganate (KMnO4) and cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively, and slowly add them to the above manganese salt solution under continuous magnetic stirring. Continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0009] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a polytetrafluoroethylene liner, sealed and placed in a stainless steel high-pressure reactor. The hydrothermal reaction was carried out in a constant temperature oven. After naturally cooling to room temperature, the reactor was removed and the precipitate was washed several times with deionized water and anhydrous ethanol until the pH was neutral. The precipitate was dried in a forced-air drying oven, ground and sieved, and the sample was placed in a muffle furnace for constant temperature calcination. After natural cooling, the composite oxide catalyst was obtained.

[0010] Furthermore, the concentration of the manganese salt solution mentioned in step (1) is 0.10-0.35 mol / L.

[0011] Further, the molar ratio of potassium permanganate to manganese acetate in step (1) is (1.0-2.0):1.

[0012] Furthermore, in step (1), the molar ratio of manganese source to cerium source is 9:1-3:7.

[0013] Furthermore, the rotation speed of the continuous magnetic stirring in step (1) is 1000-2000 r / min. The rotation speed of the vigorous stirring is 1500 r / min.

[0014] Furthermore, the temperature of the hydrothermal reaction in step (2) is 80-120℃, and the time of the hydrothermal reaction is 12-24h.

[0015] Furthermore, the drying temperature in step (2) is 80-120℃ and the drying time is 12-24h.

[0016] Furthermore, the calcination temperature in step (2) is 300-600℃ and the calcination time is 3-6h.

[0017] This invention provides a novel sacrificial catalyst prepared by the method described above for the removal of H2S at medium and high temperatures and for the catalytic oxidation of short-chain alkanes. The catalyst exhibits an amorphous, low-crystallinity composite structure of manganese and cerium.

[0018] This invention also provides a method for applying the novel sacrificial catalyst described above, which combines H2S removal at medium and high temperatures with catalytic oxidation of short-chain alkanes. The method includes the following steps:

[0019] The novel sacrificial catalyst was pressed into tablets and ground to a particle size range of 40 to 60 mesh. 0.1 g of the catalyst material was thoroughly mixed with 0.4 g of quartz sand and placed in a quartz tube. The total flow rate of the reaction gas was controlled at 100 mL / min (weight hourly space velocity WHSV of 60,000 mL / g). -1 h -1 The catalytic reaction is carried out in the temperature range of 250-500℃. The specific composition of the reaction gas can be: ethane concentration of 3000ppm, H2S concentration of 50ppm, O2 concentration of 2%, with the remainder being N2 as the equilibrium gas.

[0020] Compared with the prior art, the main advantages of this invention include:

[0021] (1) The sacrificial catalyst of the present invention can completely remove H2S in an oxidizing environment of 250-500℃ and prevent it from being released in the form of SO2, thus preventing H2S from being converted into SO2 and escaping from the sacrificial agent to poison subsequent catalysts, thereby constructing a long-lasting sulfur poisoning protection barrier.

[0022] (2) The sacrificial catalyst of the present invention can completely remove H2S while also having the function of catalytic oxidation of short-chain alkanes, and exhibits good ethane catalytic activity in the range of 250-500℃.

[0023] (3) The preparation cost of the present invention is low, the preparation method is simple and easy to implement, and it can efficiently remove H2S and ethane simultaneously under medium and high temperature conditions. Attached Figure Description

[0024] Figure 1 The image shows the SEM analysis of the catalyst prepared in Example 1 when used for the simultaneous removal of H2S and ethane.

[0025] Figure 2The XRD pattern of the catalyst prepared in Example 1 for the simultaneous removal of H2S and ethane.

[0026] Figure 3 The graph shows the ethane degradation activity evaluation of the catalysts prepared in Examples 1-4 and Comparative Examples 1-4 when used for the simultaneous removal of H2S and ethane.

[0027] Figure 4 The H2S outlet concentration evaluation diagram is shown for the catalysts prepared in Examples 1-4 and Comparative Examples 1-4 when used for the simultaneous removal of H2S and ethane.

[0028] Figure 5 The SO2 outlet concentration evaluation diagram is shown for the catalysts prepared in Examples 1-4 and Comparative Examples 1-4 when used for the simultaneous removal of H2S and ethane.

[0029] Figure 6 The graph shows the ethane degradation activity evaluation of the catalysts prepared in Examples 5-7 when used for the simultaneous removal of H2S and ethane.

[0030] Figure 7 The H2S outlet concentration evaluation diagram is shown for the catalysts prepared in Examples 5-7 when used for the simultaneous removal of H2S and ethane.

[0031] Figure 8 The SO2 outlet concentration evaluation diagram is shown for the catalysts prepared in Examples 5-7 when used for the simultaneous removal of H2S and ethane.

[0032] Figure 9 The catalyst prepared in Example 1 is used for ethane degradation activity evaluation during simultaneous H2S removal and long-term ethane testing at 450°C.

[0033] Figure 10 The catalyst prepared in Example 1 was used for the simultaneous removal of H2S and ethane at 450°C for a long-term test, and the H2S and SO2 outlet concentrations were evaluated.

[0034] Figure 11 Example 1 and post-catalyst Pt / MnCeO x Evaluation chart of ethane degradation activity when used in series at 450℃. Detailed Implementation

[0035] Example 1

[0036] (1) Preparation of precursor solution: Weigh 1.72 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to the acidic range to form a homogeneous manganese salt base solution. According to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O) = 1.4:1 and the molar ratio of n(Mn):n(Ce) = 7:3, weigh 1.55 g of potassium permanganate (KMnO4) solid powder and 3.13 g of cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively. Under continuous magnetic stirring, slowly add them to the above manganese salt solution and continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0037] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, a composite oxide catalyst, denoted as Mn, was obtained. 0.7 Ce 0.3 O2.

[0038] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above Mn 0.7 Ce 0.3 The O2 catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of the catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0039] Example 2

[0040] (1) Preparation of precursor solution: Weigh 2.21 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to the acidic range to form a homogeneous manganese salt base solution. According to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O) = 1.4:1 and the molar ratio of n(Mn):n(Ce) = 9:1, weigh 1.99 g of potassium permanganate (KMnO4) solid powder and 1.04 g of cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively. Under continuous magnetic stirring, slowly add them to the above manganese salt solution and continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0041] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, a composite oxide catalyst, denoted as Mn, was obtained. 0.9 Ce 0.1 O2.

[0042] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above Mn 0.9 Ce 0.1 The O2 catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of the catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0043] Example 3

[0044] (1) Preparation of precursor solution: Weigh 1.23 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to the acidic range to form a homogeneous manganese salt base solution. According to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O) = 1.4:1 and the molar ratio of n(Mn):n(Ce) = 5:5, weigh 1.11 g of potassium permanganate (KMnO4) solid powder and 5.21 g of cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively. Under continuous magnetic stirring, slowly add them to the above manganese salt solution and continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0045] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, a composite oxide catalyst, denoted as Mn, was obtained. 0.5 Ce 0.5 O2.

[0046] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above Mn 0.5 Ce 0.5 The O2 catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of the catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0047] Example 4

[0048] (1) Preparation of precursor solution: Weigh 0.55 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to the acidic range to form a homogeneous manganese salt base solution. According to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O) = 1.4:1 and the molar ratio of n(Mn):n(Ce) = 3:7, weigh 0.50 g of potassium permanganate (KMnO4) solid powder and 5.47 g of cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively. Under continuous magnetic stirring, slowly add them to the above manganese salt solution and continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0049] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, a composite oxide catalyst, denoted as Mn, was obtained. 0.3 Ce 0.7 O2.

[0050] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above Mn 0.3 Ce 0.7 The O2 catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of the catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0051] Example 5

[0052] (1) Preparation of precursor solution: Weigh 1.72 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to the acidic range to form a homogeneous manganese salt base solution. According to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O) = 1.4:1 and the molar ratio of n(Mn):n(Ce) = 7:3, weigh 1.55 g of potassium permanganate (KMnO4) solid powder and 3.13 g of cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively. Under continuous magnetic stirring, slowly add them to the above manganese salt solution and continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0053] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 300℃ for 4 h. After natural cooling, the composite oxide catalyst, denoted as MnCe-300℃, was obtained.

[0054] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above-mentioned MnCe-300℃ catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0055] Example 6

[0056] (1) Preparation of precursor solution: Weigh 1.72 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to the acidic range to form a homogeneous manganese salt base solution. According to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O) = 1.4:1 and the molar ratio of n(Mn):n(Ce) = 7:3, weigh 1.55 g of potassium permanganate (KMnO4) solid powder and 3.13 g of cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively. Under continuous magnetic stirring, slowly add them to the above manganese salt solution and continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0057] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, the composite oxide catalyst, denoted as MnCe-500℃, was obtained.

[0058] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above-mentioned MnCe-500℃ catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0059] Example 7

[0060] (1) Preparation of precursor solution: Weigh 1.72 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to the acidic range to form a homogeneous manganese salt base solution. According to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O) = 1.4:1 and the molar ratio of n(Mn):n(Ce) = 7:3, weigh 1.55 g of potassium permanganate (KMnO4) solid powder and 3.13 g of cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively. Under continuous magnetic stirring, slowly add them to the above manganese salt solution and continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0061] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was then subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, the composite oxide catalyst, denoted as MnCe-600℃, was obtained.

[0062] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above-mentioned MnCe-600℃ catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0063] Comparative Example 1

[0064] (1) Preparation of precursor solution: Weigh 2.70 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to an acidic environment to form a homogeneous manganese salt base solution. Weigh 2.43 g of potassium permanganate (KMnO4) solid powder according to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O)=1.4:1, and slowly add it to the above manganese salt solution under continuous magnetic stirring. Continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0065] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, the composite oxide catalyst, denoted as MnO2, was obtained.

[0066] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above MnO2 catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0067] Comparative Example 2

[0068] (1) Preparation of precursor solution: Weigh 4.34g of cerium nitrate (Ce(NO3)3·6H2O) solid powder and dissolve it in 50mL of deionized water. Stir magnetically until completely clear, then add 2mol / L sodium hydroxide solution dropwise until pH=10.

[0069] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, the composite oxide catalyst, denoted as CeO2, was obtained.

[0070] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above CeO2 catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0071] Comparative Example 3

[0072] (1) Preparation of precursor solution: Weigh 1.72 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to the acidic range to form a homogeneous manganese salt base solution. According to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O) = 1.4:1 and the molar ratio of n(Mn):n(Ce) = 49:1, weigh 1.55 g of potassium permanganate (KMnO4) solid powder and 0.15 g of cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively, and slowly add them to the above manganese salt solution under continuous magnetic stirring. Continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0073] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, a composite oxide catalyst, denoted as Mn, was obtained. 0.98 Ce 0.02 O2.

[0074] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above Mn 0.98 Ce 0.02 The O2 catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of the catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0075] Comparative Example 4

[0076] (1) Preparation of precursor solution: Weigh 0.22 g of manganese acetate (Mn(Ac)2·4H2O) and dissolve it in 40 mL of deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to adjust the pH of the system to the acidic range to form a homogeneous manganese salt base solution. According to the molar ratio of n(KMnO4):n(Mn(Ac)2·4H2O) = 1.4:1 and the molar ratio of n(Mn):n(Ce) = 1:9, weigh 0.24 g of potassium permanganate (KMnO4) solid powder and 9.38 g of cerium nitrate (Ce(NO3)3·6H2O) solid powder respectively. Under continuous magnetic stirring, slowly add them to the above manganese salt solution and continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution.

[0077] (2) Mild hydrothermal crystallization: The precursor solution was transferred to a 100 mL polytetrafluoroethylene liner, sealed, and placed in a stainless steel high-pressure reactor. The reactor was subjected to a hydrothermal reaction at 100±1℃ for 24 h in a constant-temperature oven. After natural cooling to room temperature, the reactor was removed. The precipitate was washed several times alternately with deionized water and anhydrous ethanol until the pH was neutral. The product was dried in an 80℃ forced-air drying oven for 12 h, ground, and then calcined in a muffle furnace at 500℃ for 4 h. After natural cooling, a composite oxide catalyst, denoted as Mn, was obtained. 0.1 Ce 0.9 O2.

[0078] (3) Simultaneous removal reaction test of H2S and ethane at medium and high temperatures: The above Mn 0.1 Ce 0.9 The O2 catalyst was tableted using a tablet press, crushed and sieved to a particle size range of 40 to 60 mesh, and 0.1 g of the catalyst material was mixed with 0.4 g of quartz sand and placed in a programmed temperature fixed-bed quartz reactor for reaction testing. The total flow rate of the reaction gas was 100 mL / min. -1 (Weight hourly space velocity (WHSV) is 60,000 mL / g) -1 h -1 It contains 3000ppm ethane, 50ppm H2S, 2vol.% O2, and N2 in equilibrium.

[0079] Figure 1 The image shows a SEM image of the catalyst from Example 1. It can be seen that the catalyst from Example 1 exhibits an interconnected blocky morphology.

[0080] Figure 2 The image shows the XRD pattern of the catalyst in Example 1. It can be seen that the catalyst in Example 2 does not exhibit obvious characteristic diffraction patterns, indicating an amorphous structure.

[0081] Figure 3The graphs show the ethane degradation activity evaluation of the catalysts prepared in Examples 1-4 and Comparative Examples 1-4 for the simultaneous removal of H2S and ethane. It can be seen that the catalysts prepared in Examples 1-4 exhibit excellent activity in the ethane catalytic reaction. Specifically, these catalysts achieve an ethane conversion rate of 50% (T50) before the reaction temperature reaches 300°C, and an ethane conversion rate of 90% (T90) before 400°C. In stark contrast, the catalysts in Comparative Examples 1-4 show significantly inferior ethane catalytic activity, with a large gap compared to the examples. This fully demonstrates that within the manganese-cerium ratio range defined in this invention, the catalytic activity of the catalyst for ethane can be effectively improved.

[0082] Figure 4 The graph shows the H2S outlet concentration evaluation for the catalysts prepared in Examples 1-4 and Comparative Examples 1-4 when used for the simultaneous removal of H2S and ethane. It can be seen that within the temperature range of 250-500℃, the H2S outlet concentration for both examples and comparative examples is consistently 0. This result indicates that within this specific temperature range, the catalysts involved in both examples and comparative examples possess the ability to achieve complete H2S removal.

[0083] Figure 5 The graph shows the SO2 outlet concentration evaluation of the catalysts prepared in Examples 1-4 and Comparative Examples 1-4 when used for the simultaneous removal of H2S and ethane. It can be seen that during the test under oxidizing conditions, except for Comparative Example 2 which showed a relatively large SO2 release, the SO2 release in Examples 1-4 and Comparative Examples 1 and 3-4 remained consistently at 0. This phenomenon fully demonstrates that the catalysts prepared by the potassium permanganate mild hydrothermal synthesis method in Examples 1-4 and Comparative Examples 1 and 3-4 exhibit excellent desulfurization performance under oxidizing conditions and can effectively prevent the re-release of sulfur in the form of SO2.

[0084] Figure 6 The graphs show the ethane degradation activity evaluation of the catalysts prepared in Examples 5-7 for the simultaneous removal of H2S and ethane. It can be seen that the calcination temperature has a significant impact on the ethane catalytic activity of the catalysts, with Example 6 exhibiting the best ethane catalytic activity. This indicates that the calcination temperature should be controlled at 500℃.

[0085] Figure 7 The graphs show the H2S outlet concentration evaluation of the catalysts prepared in Examples 5-7 when used for simultaneous H2S and ethane removal. It can be seen that the calcination temperature has no significant effect on the H2S removal capacity of the catalysts. Within the temperature range of 250-500℃, all three catalysts exhibit low H2S outlet concentrations, indicating that they all have good H2S removal efficiency within this temperature range.

[0086] Figure 8The graphs show the SO2 outlet concentration evaluation of the catalysts prepared in Examples 5-7 for the simultaneous removal of H2S and ethane. It can be seen that the calcination temperature has a certain impact on the SO2 removal capacity of the catalysts. Within the temperature range of 250-500℃, the catalysts of different examples showed different performances: Example 7 exhibited relatively high SO2 release in the reaction temperature ranges of 250℃ and 300℃. This is because the high-temperature calcination process easily induces irreversible phase transitions in the manganese-based catalyst, and also causes the collapse and sintering of its porous structure, resulting in a significant decrease in specific surface area and a reduction in the number of active sites, thus severely weakening its desulfurization performance. Examples 5 and 6, on the other hand, performed excellently, effectively maintaining the SO2 outlet concentration at 0 level and significantly reducing SO2 release.

[0087] Figure 9 The graph shows the ethane degradation activity evaluation of the catalyst of Example 1 during a long-term test at 450°C for simultaneous H2S and ethane removal. It can be seen that the catalyst of Example 1 maintained an ethane conversion rate of 90% (T90) for up to 40 hours during the long-term test. This data fully demonstrates that the catalyst of Example 1 possesses excellent ethane degradation ability and can maintain effective catalytic degradation of ethane for a relatively long period.

[0088] Figure 10 The graph shows the H2S and SO2 outlet concentrations of the catalyst in Example 1 during a long-term test at 450°C for simultaneous H2S and ethane removal. It can be seen that the H2S outlet concentration of the catalyst remained consistently at 0 throughout the 60-hour test period; while the SO2 outlet concentration only reached a 5% sulfur breakthrough rate after 55 hours of testing. This data clearly demonstrates that the catalyst in Example 1 possesses excellent desulfurization capabilities, effectively removing H2S and suppressing the release of sulfur as SO2 during long-term testing.

[0089] Figure 11 The catalyst and post-catalyst Pt / MnCeO in Example 1 x The graph shows the ethane degradation activity evaluation when used in series at 450℃. It can be seen that the time for the tandem catalyst to achieve 90% ethane conversion (T90) can reach 90 hours. This contrasts sharply with the Pt / MnCeO₂ catalyst. x The catalyst can only last for a much shorter time. This difference clearly demonstrates that Example 1 exhibits excellent desulfurization performance, effectively reducing the poisoning effect of sulfur on the post-catalyst, thereby significantly extending the service life of the post-catalyst in practical applications.

[0090] The foregoing embodiments of this invention are merely examples intended to clearly illustrate the core content of the invention and are not intended to limit its implementation. Given the diversity and complexity of implementation methods, it is neither necessary nor possible to list all possible implementation methods here. However, it should be clarified that any non-substantial improvements made within the framework of the inventive concept and technical solution, or any modifications made without substantial alteration, should be included within the scope of protection of the claims of this invention.

Claims

1. A method for preparing a novel sacrificial catalyst for the removal of H2S at medium and high temperatures, which also serves as a catalyst for the catalytic oxidation of short-chain alkanes, characterized in that, Includes the following steps: (1) Preparation of precursor solution: Weigh an appropriate amount of manganese acetate and dissolve it in deionized water. Stir magnetically until completely clear, then add concentrated nitric acid dropwise to form a homogeneous manganese salt solution. Weigh potassium permanganate and cerium nitrate solid powder respectively, and slowly add them to the above manganese salt solution under continuous magnetic stirring. Continue to stir vigorously to fully complex the components and form a dark brown homogeneous precursor solution. (2) Mild hydrothermal crystallization: The precursor solution was transferred to the liner of the reactor for hydrothermal reaction. After naturally cooling to room temperature, it was taken out and washed several times with deionized water and anhydrous ethanol until the pH was neutral. After drying, grinding and sieving, it was calcined at a constant temperature and cooled to obtain the composite oxide catalyst.

2. The method for preparing the sacrificial agent for medium- and high-temperature H2S removal with catalytic oxidation performance of short-chain alkanes according to claim 1, characterized in that, In step (1), the concentration of the manganese salt solution is 0.10-0.35 mol / L.

3. The method for preparing the novel sacrificial catalyst for medium- and high-temperature H2S removal and short-chain alkane catalytic oxidation according to claim 1, characterized in that, In step (1), the molar ratio of potassium permanganate and manganese acetate is (1.0-2.0):

1.

4. The method for preparing the novel sacrificial catalyst for medium- and high-temperature H2S removal and short-chain alkane catalytic oxidation according to claim 1, characterized in that, In step (1), the molar ratio of manganese source to cerium source is 9:1-3:

7.

5. The method for preparing the novel sacrificial catalyst for medium- and high-temperature H2S removal and short-chain alkane catalytic oxidation according to claim 1, characterized in that, The rotation speed of the continuous magnetic stirring in step (1) is 1000-2000 r / min; the rotation speed of the vigorous stirring is 1500 r / min.

6. The method for preparing the novel sacrificial catalyst for medium- and high-temperature H2S removal and short-chain alkane catalytic oxidation according to claim 1, characterized in that, In step (2), the temperature of the hydrothermal reaction is 80-120℃ and the time of the hydrothermal reaction is 12-24h.

7. The method for preparing the novel sacrificial catalyst for medium- and high-temperature H2S removal and short-chain alkane catalytic oxidation according to claim 1, characterized in that, In step (2), the drying temperature is 80-120℃ and the drying time is 12-24h.

8. The method for preparing the novel sacrificial catalyst for medium- and high-temperature H2S removal and short-chain alkane catalytic oxidation according to claim 1, characterized in that, In step (2), the calcination temperature is 300-600℃ and the calcination time is 3-6h.

9. A novel sacrificial catalyst for medium- and high-temperature H2S removal and short-chain alkane catalytic oxidation, prepared by the method according to any one of claims 1 to 8, characterized in that, The catalyst exhibits excellent simultaneous removal activity of H2S and short-chain alkanes at 250-500℃.

10. The application of the novel sacrificial catalyst of claim 9 in the simultaneous removal of H2S and short-chain alkanes.

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