Graphite oxide and manganese oxide as well as preparation method and application thereof

Abstract

The invention relates to a preparation method of graphite oxide and manganese oxide, which comprises the following steps: 1, mixing graphite with concentrated acid, and adding potassium permanganate in batches to obtain a mixed material; 2, after the mixed material is subjected to a heating reaction, water is added for stirring, a liquid phase and a solid phase are obtained through solid-liquid separation, the liquid phase is a separation stock solution, and the solid phase is recycled to obtain graphite oxide; and 3, mixing the separation stock solution with an auxiliary agent, carrying out a hydrothermal reaction, and recovering a solid-phase material. According to the preparation method, the manganese oxide is prepared while the graphite oxide is prepared, the use amount of potassium permanganate in the graphite oxide preparation process is high, the oxidation speed is high, the oxidation effect is good, an additional manganese source does not need to be added when the manganese oxide is prepared, and the preparation cost of the manganese oxide is reduced. According to the graphite oxide and manganese oxide preparation process, the content of manganese ions and the like in wastewater can be remarkably reduced, and the problem that sewage discharge pollutes the environment is solved.

Description

Technical Field

[0001] The present invention belongs to the field of graphite oxide, and specifically relates to graphite oxide and manganese oxide, and preparation methods and uses thereof. Background Art

[0002] Graphite oxide is an important type of graphite product, which can be used to prepare downstream popular products such as expanded graphite and graphene. At present, the main method of producing graphite oxide is to oxidize graphite with strong oxidants such as potassium permanganate, but the existing method has a high manganese ion content in the wastewater, which is difficult to treat and has great environmental pressure.

[0003] Hydrogen sulfide and carbonyl sulfide are the main forms of sulfide impurities in common gases, especially hydrogen sulfide and carbonyl sulfide. Existing international standards have strict requirements on the sulfide content of hydrogen used in fuel cells. How to ensure that the sulfide content of hydrogen used in fuel cells is qualified is the key technology for using hydrogen in fuel cells. Existing desulfurization technologies rarely report on desulfurization technologies for mixed sulfides and desulfurization technologies for mixed sulfides using manganese oxides. Summary of the invention

[0004] The purpose of the present invention is to provide a graphite oxide and a manganese oxide and a preparation method and use thereof. The preparation method of the present invention can prepare manganese oxide while preparing graphite oxide, and the amount of potassium permanganate used in the process of preparing graphite oxide is relatively high, the oxidation speed is fast, the oxidation effect is good, and no additional manganese source needs to be added when preparing manganese oxide, thereby reducing the preparation cost of manganese oxide. The present invention can produce manganese oxide while preparing graphite oxide, and can significantly reduce the content of manganese ions and the like in wastewater, thereby solving the problem of sewage discharge polluting the environment in the graphite oxide process.

[0005] In order to achieve the above object, the first aspect of the present invention provides a method for preparing graphite oxide and manganese oxide, the method comprising:

[0006] S1: After mixing graphite with concentrated acid, potassium permanganate is added in batches to obtain a mixed material;

[0007] S2: After the mixed material is heated for reaction, water is added and stirred, and a liquid phase and a solid phase are obtained by solid-liquid separation, wherein the liquid phase is the separation stock solution, and the solid phase is recovered to obtain graphite oxide;

[0008] S3: mixing the separated stock solution with an auxiliary agent, performing a hydrothermal reaction and recovering a solid phase material;

[0009] Wherein, the auxiliary agent is one or more of ammonium persulfate, sodium persulfate, potassium persulfate and sodium hypochlorite, and the mass ratio of the auxiliary agent to the graphite is (0.2-10):1;

[0010] The conditions of the hydrothermal reaction include: temperature of 100-200° C. and time of 1-72 h.

[0011] Optionally, the mass ratio of the additive to the graphite is (0.5-5):1;

[0012] The conditions of the hydrothermal reaction include: temperature of 100-150° C. and time of 2-24 hours.

[0013] Optionally, the graphite oxide has an oxygen content of 15 to 40% by weight and a carbon content of 60 to 85% by weight.

[0014] Optionally, the graphite is one or more of natural flake graphite, natural cryptocrystalline graphite and artificial graphite;

[0015] The graphite has a carbon content of more than 98% by weight, an ash content of less than 2%, and a mesh size of 20 to 2000 meshes.

[0016] Optionally, the concentrated acid is selected from one or more of sulfuric acid, nitric acid and perchloric acid;

[0017] C 0 Any concentration between N-10% and N+10%, preferably C 0 Any concentration between N-5% and N+5%, C 0 is the concentration of the concentrated acid, and N is the maximum concentration of the analytical pure reagent grade of the concentrated acid.

[0018] Optionally, the mass ratio of the concentrated acid to the graphite is (20-150):1, preferably (30-100):1;

[0019] The mass ratio of the potassium permanganate to the graphite is (2-8):1, preferably (3-6):1;

[0020] The mass ratio of potassium permanganate to the graphite mixed in each batch is (0.05-1):1, preferably (0.1-0.5):1;

[0021] The mass ratio of the amount of water added to the amount of graphite added is (50-2000):1, preferably (80-250):1.

[0022] Optionally, the method further comprises:

[0023] In step S1, potassium permanganate is added in batches and mixed, and the temperature is controlled to be below 40° C., preferably below 30° C., and more preferably below 20° C., and stirred for 0.2 to 12 hours; sodium nitrate and hydrogen peroxide are not added during the reaction;

[0024] In step S2, the conditions for the heating reaction include: a temperature of 30 to 60°C and a time of 0.2 to 6 hours; and a time of stirring while adding water is 0.1 to 5 hours.

[0025] The second aspect of the present invention provides a manganese oxide prepared by the method provided by the first aspect of the present invention.

[0026] Optionally, in the XRD spectrum of the manganese oxide, characteristic peaks exist at 2θ of 28.6±0.5°, 37.4±0.3°, 41.0±0.3°, 42.8±0.3°, 56.6±0.3°, 59.4±0.3°, 64.9±0.3° and 72.4±0.3°, respectively; and the half-peak width of the diffraction peak at 28.6±0.5° is greater than 0.1°;

[0027] Based on the mass of the manganese oxide, the manganese oxide has a Mn content of 30 to 55 weight percent, a S content of 0.8 to 10 weight percent, and a K content of 1 to 10 weight percent.

[0028] The specific surface area of ​​the manganese oxide is 10 to 100 m 2 / g, preferably 30 to 60 m 2 / g, the pore volume is 0.05-0.5 ml / g, preferably 0.1-0.3 ml / g, and the pore diameter is 12-36 nm, preferably 15-30 nm.

[0029] The third aspect of the present invention provides use of the manganese oxide provided by the second aspect of the present invention in removing sulfides in gas.

[0030] Through the above technical scheme, the preparation method of the present invention mixes graphite with concentrated acid and potassium permanganate first, and then mixes with an auxiliary agent for hydrothermal reaction, so as to prepare manganese oxide while preparing graphite oxide. Since the amount of potassium permanganate used in the process of preparing graphite oxide is relatively high, there is no need to add an additional manganese source, and sodium nitrate and hydrogen peroxide are not added during the reaction process, thereby reducing the preparation cost of manganese oxide. The present invention produces manganese oxide while preparing graphite oxide, and the prepared graphite oxide and manganese oxide show excellent performance in the process of treating wastewater, which can significantly reduce the content of manganese ions and the like in wastewater, thereby solving the problems of sewage discharge and environmental pollution in the process of preparing graphite oxide.

[0031] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0033] Figure 1 This is the XRD pattern of the manganese oxide prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0034] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0035] A first aspect of the present invention provides a method for preparing graphite oxide and manganese oxide, the method comprising:

[0036] S1: After mixing graphite with concentrated acid, potassium permanganate is added in batches to obtain a mixed material;

[0037] S2: After the mixed material is heated for reaction, water is added and stirred, and a liquid phase and a solid phase are obtained by solid-liquid separation, wherein the liquid phase is the separation stock solution, and the solid phase is recovered to obtain graphite oxide;

[0038] S3: mixing the separated stock solution with an auxiliary agent, performing a hydrothermal reaction and recovering a solid phase material;

[0039] The auxiliary agent is one or more of ammonium persulfate, sodium persulfate, potassium persulfate and sodium hypochlorite, preferably ammonium persulfate and potassium persulfate, and the mass ratio of the auxiliary agent to the graphite is (0.2-10):1, preferably (0.5-5):1, and more preferably (1-3):1;

[0040] The conditions of the hydrothermal reaction include: a temperature of 100 to 200° C., preferably 100 to 150° C., and a time of 1 to 72 hours, preferably 2 to 24 hours.

[0041] The preparation method of the present invention is to first react graphite with concentrated acid and potassium permanganate, and then obtain a separated stock solution of graphite oxide, and then mix it with an auxiliary agent for hydrothermal reaction, so as to prepare manganese oxide while preparing graphite oxide. Since the amount of potassium permanganate used in the process of preparing graphite oxide is relatively high, no additional manganese source needs to be added, and sodium nitrate and hydrogen peroxide are not added in the reaction process, the process safety is greatly improved, and the preparation cost of manganese oxide is reduced.

[0042] In the above embodiment, the mass ratio of the additive to the graphite and the hydrothermal reaction conditions are controlled within a preferred range to carry out the reaction, which is beneficial to improving various properties of manganese oxide and graphite oxide.

[0043] In a specific embodiment of the present invention, the oxygen content of the graphite oxide is 15 to 40% by weight, preferably 20 to 35% by weight, and the carbon content is 60 to 85% by weight, preferably 65 to 80% by weight.

[0044] In a specific embodiment of the present invention, the graphite is one or more of natural flake graphite, natural cryptocrystalline graphite and artificial graphite, preferably natural flake graphite;

[0045] The graphite has a carbon content of 98 wt % or more, preferably 99 wt % or more, preferably 99.9 wt % or more, an ash content of 2 % or less, preferably 1 % or less, more preferably 0.1 % or less, and a mesh size of 20 to 2000 mesh, preferably 50 to 500 mesh.

[0046] In a specific embodiment of the present invention, the concentrated acid is selected from one or more of sulfuric acid, nitric acid and perchloric acid, preferably sulfuric acid;

[0047] C 0 Any concentration between N-10% and N+10%, preferably C 0 Any concentration between N-5% and N+5%, C 0 is the concentration of the concentrated acid, and N is the maximum concentration of the analytical pure reagent grade of the concentrated acid.

[0048] In a specific embodiment of the present invention, the mass ratio of the concentrated acid to the graphite is (20-150):1, preferably (30-100):1;

[0049] The mass ratio of the potassium permanganate to the graphite is (2-8):1, preferably (3-6):1;

[0050] The mass ratio of potassium permanganate to the graphite mixed in each batch is (0.05-1):1, preferably (0.1-0.5):1;

[0051] The mass ratio of the amount of water added to the amount of graphite added is (50-2000):1, preferably (80-250):1.

[0052] In a specific embodiment of the present invention, the method further comprises:

[0053] In step S1, after mixing with potassium permanganate, the temperature is controlled to be below 40° C., preferably below 30° C., more preferably below 20° C., and stirred for 0.2 to 12 h, preferably 0.5 to 6 h; sodium nitrate and hydrogen peroxide are not added during the reaction;

[0054] In step S2, the conditions for the heating reaction include: a temperature of 30 to 60°C, preferably 40 to 50°C, a time of 0.2 to 6 hours, preferably 0.5 to 4 hours; and a time for stirring after adding water of 0.1 to 5 hours, preferably 0.5 to 2 hours.

[0055] The second aspect of the present invention provides a manganese oxide prepared by the method provided by the first aspect of the present invention.

[0056] In a specific embodiment of the present invention, the XRD spectrum of the manganese oxide has characteristic peaks at 2θ of 28.6±0.5°, 37.4±0.3°, 41.0±0.3°, 42.8±0.3°, 56.6±0.3°, 59.4±0.3°, 64.9±0.3° and 72.4±0.3°, respectively; and the half-peak width of the diffraction peak at 28.6±0.5° is greater than 0.1°;

[0057] Based on the mass of the manganese oxide, the manganese oxide has a Mn content of 30 to 55% by weight, preferably 35 to 50% by weight; a S content of 0.8 to 10% by weight, preferably 1.2 to 6% by weight; a K content of 1 to 10% by weight, preferably 3 to 8% by weight; and the remainder is mainly O.

[0058] The specific surface area of ​​the manganese oxide is 10 to 100 m 2 / g, preferably 30 to 60 m 2 / g, the pore volume is 0.05-0.5 ml / g, preferably 0.1-0.3 ml / g, and the pore diameter is 12-36 nm, preferably 15-30 nm.

[0059] The present invention produces manganese oxide crystalline powder while preparing graphite oxide, and the method of the present invention can significantly reduce the content of manganese ions and the like in wastewater. Generally, the manganese ion content is less than 50 ppm and can be directly discharged, thereby solving the problem of wastewater discharge polluting the environment when preparing graphite oxide.

[0060] The third aspect of the present invention provides use of the manganese oxide provided by the second aspect of the present invention in removing sulfides in gas.

[0061] The present invention is further illustrated by the following examples, but the present invention is not limited thereto.

[0062] The reagents used in the present invention are all commercially available analytically pure reagents.

[0063] Example 1

[0064] a. Add 150 ml of concentrated sulfuric acid (mass concentration greater than 98%) and 5 g of graphite into a beaker to obtain a mixed solution;

[0065] b. Add 25 g of potassium permanganate into the mixed solution obtained in step a in 5 batches, and stir and mix at 10° C. for 1 h to obtain a mixed material;

[0066] c. Stir the mixture obtained in step b at 35°C under autogenous pressure for 2h;

[0067] d. Add 150 ml of water to the mixture in step c, continue stirring and reacting at 90° C. for 1 hour, and then filter to obtain graphite oxide solid and separation stock solution;

[0068] e. At 120° C. and autogenous pressure, the separated stock solution in step d was mixed with 5 g of potassium persulfate, and subjected to hydrothermal treatment for 24 h. The solid-liquid separation was performed to obtain the solid phase manganese oxide.

[0069] The XRD spectrum of the prepared manganese oxide is shown in Figure 1 shown.

[0070] Example 2

[0071] The preparation method in Example 1 was adopted, except that in step e, the separated stock solution in step d was mixed with 1 g of potassium persulfate.

[0072] Example 3

[0073] The preparation method in Example 1 was adopted, except that in step e, the reaction temperature was 160° C. and the hydrothermal treatment time was 2 h.

[0074] Example 4

[0075] The preparation method in Example 1 was adopted, except that in step e, 5 g of potassium persulfate was replaced by 5 g of ammonium persulfate.

[0076] Example 5

[0077] The preparation method in Example 1 was adopted, except that, in step a, 100 ml of concentrated sulfuric acid was added.

[0078] Example 6

[0079] The preparation method in Example 1 was adopted, except that 15 g of potassium permanganate was added in step b.

[0080] Example 7

[0081] The preparation method in Example 1 was adopted, except that in step c, the reaction temperature was 30°C.

[0082] Example 8

[0083] The preparation method in Example 1 was adopted, except that in step d, 450 ml of water was added.

[0084] Example 9

[0085] The preparation method in Example 1 was adopted, except that in step b, the mass ratio of potassium permanganate to graphite added in each batch was 5:3, that is, potassium permanganate was added in 3 batches.

[0086] Example 10

[0087] The preparation method in Example 1 was adopted, except that in step a, 150 ml of concentrated nitric acid was added instead of concentrated sulfuric acid.

[0088] Comparative Example 1

[0089] The preparation method in Example 1 is adopted, except that in step b, 25 g of potassium permanganate is added once to the mixed solution obtained in step a.

[0090] Comparative Example 2

[0091] The preparation method in Example 1 was adopted, except that in step e, the reaction temperature was 250° C. and the hydrothermal treatment time was 96 h.

[0092] Comparative Example 3

[0093] The preparation method in Example 1 was adopted, except that in step e, the separated stock solution in step d was mixed with 30 g of potassium persulfate.

[0094] Test Case

[0095] The XRD spectrum of the sample was obtained by a Rigaku D / MaxA-ⅢA X-ray diffractometer. Test conditions: Cu target Kα radiation, voltage 30 kV, current 20 mA, step scan, scanning range 5°~80°.

[0096] The element content of the sample was determined by XPS on a VGESCA-LABS X-ray photoelectron spectrometer, using Mg Kα X-rays as the laser source and the C1s binding energy (284.6 eV) of the surface contamination carbon to calibrate the binding energy of each element in the desulfurizer surface species.

[0097] The warm nitrogen adsorption-desorption test (BET) was carried out on a JW-BK200C surface area and pore size analyzer produced by Beijing Jingwei Gaobo Co., Ltd. The specific surface area and pore volume were calculated using the two-parameter BET equation, and the pore distribution was calculated using the BJH method.

[0098] 500 mg of the examples and comparative examples prepared by the present invention were loaded as desulfurizers into the constant temperature section of the reactor of a passivated fixed bed microreactor with an inner diameter of 12 mm and a length of 500 mm, and filled with quartz sand on the top and bottom. The sulfide content in the sulfur-containing compound raw material is 5000 ppm (the carrier gas is hydrogen, and the sulfide is a complex of hydrogen sulfide and carbonyl sulfide in a molar ratio of 1:1). The desulfurization reaction is carried out at 60°C and 2MPa at a flow rate of 100 ml / min. The sulfide content in the material after the desulfurization reaction is analyzed online, and the sulfide removal rate is calculated. The results of the sulfide removal rate at 1 hour are shown in Table 1, and other characterization results of the prepared samples are shown in Table 2. The XRD pattern of the manganese oxide of Example 1 prepared by the present invention is shown in Table 1. Figure 1 shown.

[0099] Table 1

[0100]

[0101]

[0102] Table 2

[0103]

[0104] According to the test results in Table 1 and Table 2, it can be seen that the manganese oxide prepared by the preparation method provided by the present invention has a larger specific surface area and pore volume and a moderate pore size compared with the comparative example, and exhibits excellent performance in removing sulfur compounds in the reaction process of removing sulfides in the gas, and the removal rate of sulfur compounds in the material reaches more than 90%. At the same time, there is no need to add sodium nitrate and hydrogen peroxide during the reaction process, which reduces the cost of preparing materials, and the manganese oxide produced by the same can significantly reduce the content of manganese ions and the like in wastewater.

[0105] It can be seen from the test results of Examples 1 to 10 that when the preparation method, the type and amount of the auxiliary agent and the reaction conditions are within the specified range of the present invention, the effect and performance of the product prepared by the present invention can be improved. By comparing Example 1 with Examples 2 to 10, it can be seen that when the type and amount of the auxiliary agent, the hydrothermal reaction conditions, the type and amount of concentrated acid, the amount of potassium permanganate and the batch added, the heating temperature, the stirring time, and the mass ratio of the amount of water added to the amount of graphite added are all within the preferred specified range of the present invention, the performance of the manganese oxide prepared by the present invention in removing sulfides can be further improved and the manganese ion content in the preparation wastewater can be significantly reduced.

[0106] From the test results of Comparative Examples 1 to 3, it can be seen that in Comparative Example 1, potassium permanganate is added to the graphite at one time, the reaction temperature rises rapidly to above 80°C, and part of the material splashes, resulting in uneven adsorption of potassium permanganate on the graphite, which leads to excessively large pore volume and pore diameter of the prepared manganese oxide, poor adsorption effect on sulfides in the gas, low removal rate, and excessively high manganese ion content in the wastewater; in Comparative Example 2, the hydrothermal treatment temperature is too high and the treatment time is too long. Excessive temperature will cause the oxygen-containing groups to be thermally decomposed, thereby affecting the product structure. The structure results in that the specific surface area, pore volume and pore size of the prepared manganese oxide are all small, resulting in that it cannot effectively remove sulfides in the gas, the removal rate is low, and the manganese ion content in the wastewater is higher than that in Examples 1 to 10; in Comparative Example 3, the dosage of potassium persulfate is too high, the degree of oxidation is too high, which is not conducive to the formation of manganese oxide, resulting in the prepared manganese oxide having a small specific surface area, too small pore volume and pore size, and poor product performance, resulting in that it cannot effectively remove sulfides in the gas, the removal rate is low, and the manganese ion content in the wastewater is too high.

[0107] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0108] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0109] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing manganese oxide and graphite oxide, wherein: The method includes: S1: After mixing graphite with concentrated acid, potassium permanganate is added in batches to obtain a mixed material; S2: After the mixed material is heated for reaction, water is added and stirred, and a liquid phase and a solid phase are obtained by solid-liquid separation, wherein the liquid phase is the separation stock solution, and the solid phase is recovered to obtain graphite oxide; S3: mixing the separated stock solution with an auxiliary agent, performing a hydrothermal reaction and recovering a solid phase material; Wherein, the auxiliary agent is one or more of ammonium persulfate, sodium persulfate, potassium persulfate and sodium hypochlorite, and the mass ratio of the auxiliary agent to the graphite is (0.2-10):1; The conditions of the hydrothermal reaction include: temperature of 100-200° C. and time of 1-72 h.

2. The method according to claim 1, wherein: The mass ratio of the additive to the graphite is (0.5-5):1; The conditions of the hydrothermal reaction include: temperature of 100-150° C. and time of 2-24 hours.

3. The method according to claim 1, wherein: The graphite oxide has an oxygen content of 15 to 40% by weight and a carbon content of 60 to 85% by weight.

4. The method according to claim 1, wherein: The graphite is one or more of natural flake graphite, natural cryptocrystalline graphite and artificial graphite; The graphite has a carbon content of more than 98% by weight, an ash content of less than 2%, and a mesh size of 20 to 2000 meshes.

5. The method according to claim 1, wherein: The concentrated acid is selected from one or more of sulfuric acid, nitric acid and perchloric acid; C0 is any concentration between N-10% and N+10%, preferably C0 is any concentration between N-5% and N+5%, C0 is the concentration of the concentrated acid, and N is the highest concentration of the analytical pure reagent grade of the concentrated acid.

6. The method according to claim 1, wherein: The mass ratio of the concentrated acid to the graphite is (20-150):1, preferably (30-100):1; The mass ratio of the potassium permanganate to the graphite is (2-8):1, preferably (3-6):1; The mass ratio of potassium permanganate to the graphite mixed in each batch is (0.05-1):1, preferably (0.1-0.5):1; The mass ratio of the amount of water added to the amount of graphite added is (50-2000):1, preferably (80-250):

1.

7. The method according to claim 1, wherein: The method further includes: In step S1, after mixing with potassium permanganate, the temperature is controlled to below 40° C., preferably below 30° C., more preferably below 20° C., and stirred for 0.2 to 12 hours; sodium nitrate and hydrogen peroxide are not added during the reaction; In step S2, the conditions for the heating reaction include: a temperature of 30 to 60°C and a time of 0.2 to 6 hours; and a time of stirring while adding water is 0.1 to 5 hours.

8. Manganese oxide prepared by the method according to any one of claims 1 to 7.

9. The manganese oxide according to claim 8, wherein In the XRD spectrum of the manganese oxide, characteristic peaks are present at 2θ positions of 28.6±0.5°, 37.4±0.3°, 41.0±0.3°, 42.8±0.3°, 56.6±0.3°, 59.4±0.3°, 64.9±0.3° and 72.4±0.3°, respectively; and the half-peak width of the diffraction peak at 28.6±0.5° is greater than 0.1°; Based on the mass of the manganese oxide, the manganese oxide has a Mn content of 30 to 55 weight percent, a S content of 0.8 to 10 weight percent, and a K content of 1 to 10 weight percent. The specific surface area of ​​the manganese oxide is 10 to 100 m 2 / g, preferably 30 to 60 m 2 / g, the pore volume is 0.05-0.5 ml / g, preferably 0.1-0.3 ml / g, and the pore diameter is 12-36 nm, preferably 15-30 nm.

10. Use of the manganese oxide according to claim 8 or 9 for removing sulfides in gas.

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