Process, reaction mixture and catalyst for the production of phosgene

Abstract

The invention relates to a process for the production of phosgene, comprising the gas phase reaction of carbon monoxide and chlorine in the presence of a carbon catalyst in a multitube reactor, wherein the carbon catalyst comprises a certain amount of mesopores having a pore size in the range of 2-50 nm and a total pore volume of at least 0.45 ml / g; to the use of a carbon catalyst for the production of phosgene, which carbon catalyst comprises a certain amount of mesopores having a pore size in the range of 2-50 nm and a total pore volume of at least 0.45 ml / g; and to a reaction mixture for the production of phosgene, which mixture comprises a catalyst for the production of phosgene comprising a porous material comprising carbon, micropores having a pore size of less than 2 nm and mesopores having a pore size in the range of 2-50 nm, wherein the mesopore volume of the porous material is at least 0.45 ml / g, and a gas stream G comprising carbon monoxide (CO) and chlorine (Cl2).

Description

[0001] This invention relates to a method for producing phosgene by a gas-phase reaction of carbon monoxide and chlorine in the presence of a catalyst (particularly in the presence of a specially designed carbon catalyst), a reaction mixture containing the catalyst for preparing phosgene, a catalyst comprising a porous material for preparing phosgene, and the use of said mixture and catalyst for preparing phosgene. Furthermore, this invention relates to a method for preparing said catalyst.

[0002] Phosgene is an important auxiliary material in the production of intermediate and final products in almost all branches of chemistry. In particular, phosgene is a widely used reagent in industrial carbonylation, such as in the production of isocyanates or organic acid chlorides. In terms of volume, the largest application area is in the production of diisocyanates for polyurethane chemistry, especially toluene diisocyanate or 4,4-diphenylmethane diisocyanate.

[0003] Phosgene is produced on a large scale in the catalytic gas-phase reaction of carbon monoxide and chlorine in the presence of a catalyst (e.g., an activated carbon catalyst), according to the following reaction equation:

[0004]

[0005] This reaction is strongly exothermic, with an enthalpy ΔH of -107.6 kJ / mol. To remove the heat of reaction, it is typically carried out in a tube-bundle reactor filled with catalyst (see Ullmann's Encyclopedia of Industrial Chemistry, 5th edition, chapter "Phosgene," Vol. A19, p. 413 and below, VCH Verlagsgesellschaft mbH, Weinheim, 1991). Particulate catalysts with a particle size in the range of 3-5 mm are typically used in tubes with a typical inner diameter between 35-70 mm (usually between 39-45 mm). The reaction begins at 40-50°C, but the temperature inside the tube can rise to 400°C or even higher. Carbon monoxide is usually used in excess during the reaction to ensure all chlorine is converted and to produce a large amount of chlorine-free phosgene, as chlorine causes undesirable side reactions when phosgene is subsequently used. The reaction can proceed without pressure, but is typically carried out under overpressure of 200–600 kPa (2–6 bar). Within this pressure range, the phosgene formed can be condensed downstream of the reactor using cooling water or other heat transfer fluids, such as organic heat transfer fluids, allowing the condenser to operate more economically.

[0006] Thermal management within the reactor is one of the major challenges in phosgene production, essential for achieving safe and economical production. Various methods exist for handling the heat of reaction. The primary influence on thermal management lies in specific reactor design and catalyst selection or design, allowing for the rapid removal of the generated heat of reaction by reducing heat and mass transfer limitations.

[0007] Various reactor designs are described in the prior art. Typically, in a tube-tube reactor, the contact tubes are flushed by a heat carrier that dissipates the heat of reaction generated in the reactor. Studies have shown that lateral flow in the contact tubes improves heat dissipation. To achieve this, deflector plates are usually installed in the reactor, allowing the heat carrier to flow laterally into the contact tubes through the tortuous flow pattern of the heat carrier.

[0008] For example, international patent application WO 03 / 072237 A1 describes a typical large reactor for producing phosgene.

[0009] The reactor throughput can be defined by the reactor's so-called areal load or phosgene load, which is defined as the amount of phosgene converted per unit time (usually expressed in kg / s), based on the cross-sectional area of ​​the catalyst, i.e., the sum of the inner cross-sectional areas of the catalytic contact tubes (usually expressed in m³). 2 (This is indicated by the formula). Therefore, in order to control the heat of reaction, 0.5-2 kg phosgene / m³ is typically used in the prior art. 2 The surface load of phosgene. Therefore, the surface load of phosgene is determined based on the assumption of complete compositional conversion, rather than excess, i.e., in the case of an excess of carbon monoxide relative to chlorine.

[0010] The term "reactor" as used in this application encompasses all parts of an apparatus for the chemical conversion of carbon monoxide and chlorine into phosgene. Typically, in this sense, a reactor is a single component defined by a reactor vessel. However, the reactor referred to in this application may also include two or more components with independent reactor tanks, arranged, for example, one after another (in series). In this case, the surface load refers to the total turnover, i.e., the flow rate of phosgene leaving the last reactor component (e.g., the last reactor vessel).

[0011] International patent application WO 2010 / 076208 A1 discloses an optimized arrangement of contact tubes that balances the heat transfer coefficient at the boundary layer between the contact tubes and the heat carrier across the reactor cross-section. This can be achieved by adjusting the flow path of the heat carrier in each reactor cross-section. In this reactor with optimized heat transfer flow pattern, the surface load can reach 2.74 kg phosgene / m³. 2 s.

[0012] Besides the reactor, the catalyst also has a significant impact on the efficiency of various phosgene production methods.

[0013] As described in "Selection of carbon catalyst for the industrial manufacture of phosgene" by Mitchell et al., *Catal. Sci. Technol.*, 2012, Vol. 2, pp. 2109-2115, catalyst deactivation or burnout can be observed during phosgene synthesis, necessitating equipment shutdown and catalyst replacement after appropriate operating times. This may be due, on one hand, to carbon oxidation caused by trace amounts of oxygen in the supplied chlorine. On the other hand, at higher temperatures, typically above 300°C, chlorine may also react with the active carbon of the catalyst to form volatile carbon tetrachloride (CCl4). Mitchell et al. evaluated seven commercially available carbon catalysts recommended by different suppliers for phosgene production. The low activity of the catalysts was attributed to their mesoporous nature.

[0014] Carbon catalysts are well known for their use in the production of phosgene, as illustrated in Christopher J. Mitchell et al.'s article, "Selection of carbon catalyst for the industrial manufacture of phosgene" (Hunstman Polyurethanes, Catal. Sci. Technol. Catalysis Science and Technology, 2012, pp. 2109-2115). In particular, this publication tested different carbon catalysts (porous materials). Two commercially available catalysts, Chemviron Solcarb 208C DM and Donau Supersorbon K40, exhibited the best catalytic activity. However, there remains a need to provide improved catalysts for the production of phosgene.

[0015] Activated carbon, typically derived from natural resources such as coconut shells, wood, and olive pits, is used as a catalyst. This activated carbon has a porous structure that specifically includes micropores (<2 nm) and macropores (>50 nm). The main reactions occur in the micropores, which represent a high surface area, while the macropores are responsible for transporting feedstocks into the catalyst particles and transporting products to the outside of the catalyst particles.

[0016] The activity of a catalyst depends on the appropriate ratio of transport pores to reaction pores, and therefore also on the ratio of macropores to micropores.

[0017] EP 0952961 discloses a method for preparing phosgene by reacting chlorine with carbon monoxide in the presence of a carbon catalyst. More specifically, it relates to a method for producing phosgene in a manner that minimizes the production of the harmful chemical carbon tetrachloride. In this patent, the micropore to macropore volume ratio is required to be less than 3.5, preferably less than 2.0, to minimize mass transfer limitations.

[0018] However, even with this measure, transport limitations remain. This limitation leads to low catalyst activity and long residence times of components within the particles at high temperatures, such as through the formation of chlorinated hydrocarbons from carbon and chlorine (see Khachatryan and Dellinger, “Formation of chlorinated hdyrocarbons from the reaction of chlorine atoms and activated carbon”, Chemosphere 52 (2003), pp. 709-716), resulting in catalyst deactivation.

[0019] Lower activity necessitates higher catalyst loading and larger reactors. Catalyst deactivation leads to production unit shutdowns for catalyst replacement, resulting in production losses. Incomplete chlorine conversion due to catalyst deactivation can cause quality problems in downstream phosgene applications.

[0020] The purpose of this application is to overcome the shortcomings of the prior art.

[0021] The technical problem to be solved by the present invention is to provide a method and catalyst for producing phosgene, which exhibits increased catalyst activity and reduced catalyst deactivation, thereby achieving a longer catalyst lifetime and reducing the formation of unwanted byproducts (e.g., carbon tetrachloride) in phosgene synthesis.

[0022] Therefore, the present invention relates to a method for producing phosgene, comprising the gas-phase reaction of carbon monoxide and chlorine in a multi-tube reactor in the presence of a carbon catalyst, wherein the carbon catalyst comprises a certain amount of mesopores with a pore size in the range of 2-50 nm and a total pore volume of at least 0.45 ml / g.

[0023] Furthermore, an object of the present invention is to provide a novel reaction mixture for generating phosgene. In particular, it is necessary to provide a novel reaction mixture containing a catalyst for producing phosgene that exhibits higher catalytic activity and longer catalytic lifetime compared to commercially available catalysts, and reduces the formation of CCl4 during phosgene preparation.

[0024] Therefore, the present invention also relates to a reaction mixture for preparing phosgene, the mixture comprising:

[0025] (i) A catalyst for preparing phosgene, comprising a porous material including carbon, micropores, and mesopores, wherein the micropores have a pore size less than 2 nm, and the mesopores have a pore size in the range of 2-50 nm, wherein the volume of the mesopores in the porous material is at least 0.45 ml / g; and

[0026] (ii) A gas stream G containing carbon monoxide (CO) and chlorine (Cl2).

[0027] The technical problem is solved by the method according to claim 1, the reaction mixture according to claim 21, the catalyst according to claims 31 and 33, and the use according to claim 20.

[0028] As used herein, unless the context otherwise requires, the following terms shall have the meanings specified below.

[0029] "Carbon materials" refers to materials or substances that are essentially composed of carbon. Carbon materials include ultrapure carbon materials, amorphous carbon materials, and crystalline carbon materials. Examples of carbon materials include, but are not limited to, activated carbon, pyrolyzed dried carbon, and pyrolytic polymer compositions.

[0030] "TXRF impurities" or "TXRF elements" can be any impurity element with an atomic number between 11 and 92 (i.e., from beryllium to uranium). The phrases "total TXRF impurity content" and "total TXFR impurity level" both refer to the sum of all TXFR impurities present in a sample (e.g., a polymer composition, a cured polymer composition, or a carbon material). TXRF impurity concentration and identification can be determined by total reflectance X-ray fluorescence (TXRF).

[0031] "Activation" and "activation" refer to the process of heating raw materials or carbonized / pyrolytic substances at an activation residence temperature during exposure to an oxidizing atmosphere (such as carbon dioxide, oxygen, steam, or a combination thereof) to produce "activated" substances (such as activated cryogels or activated carbon materials). The activation process typically results in the exfoliation of particle surfaces, thereby increasing surface area. Alternatively, activation can be achieved chemically, for example, by impregnating carbon-containing precursor materials with chemicals (such as acids like phosphoric acid or bases like potassium hydroxide, sodium hydroxide, or salts like zinc chloride) followed by carbonization. "Activated" refers to materials or substances that have undergone an activation process, such as carbon materials.

[0032] "Impurities" or "impurity elements" refer to unwanted foreign substances (e.g., chemical elements) in a material that differ from the chemical composition of the base material. For example, impurities in carbon materials refer to any element or combination of elements other than carbon present in the carbon material. Impurity levels are typically expressed in parts per million (ppm).

[0033] "Ultra-pure" refers to a substance with a total TXRF impurity content of less than 0.050%. For example, "ultra-pure carbon material" is a carbon material with a total TXRF impurity content of less than 0.050% (i.e., 500 ppm).

[0034] "Ash content" refers to the non-volatile inorganic substances remaining after a substance decomposes at high temperatures. Here, it is assumed that non-volatile elements are completely converted into the expected combustion products (i.e., oxides), and the ash content of carbon materials is calculated based on the total impurity content measured by total internal reflection X-ray fluorescence (TXRF).

[0035] A "pore" refers to an opening or depression on a surface, or a channel in a carbon material (e.g., pyrolytic carbon material, pyrolytic polymer composition, activated carbon material, activated polymer composition, etc.). A pore can be a single channel or connected to other channels in a continuous network throughout the structure.

[0036] "Pore structure" refers to the surface layout of pores within carbon materials such as activated carbon. The components of pore structure include pore size, mesopore volume, surface area, density, pore size distribution, and pore length. The pore structure of activated carbon materials typically includes micropores and mesopores. For example, in some embodiments, the ratio of micropores to mesopores is optimized to improve catalytic performance.

[0037] "Mesopore" typically refers to pores with a diameter between 2 and 50 nanometers, while the term "micropore" refers to pores with a diameter less than 2 nanometers. "Macropore" refers to pores with a diameter greater than 50 nanometers.

[0038] "Surface area" refers to the total specific surface area of ​​a substance that can be measured using BET technology. Surface area is usually expressed in meters (m²). 2 / g is the unit. The BET (Brunauer / Emmett / Teller) technique uses an inert gas, such as nitrogen, to measure the amount of gas adsorbed on a material and is commonly used in the art to determine the accessible surface area of ​​a material.

[0039] "Total pore volume" refers to the total pore volume that can be measured using nitrogen adsorption technology. Total pore volume is typically expressed in cm³. 3 / g is the unit.

[0040] "NLDFT surface area" refers to the total specific surface area of ​​a material measured using a dual isotherm NLDFT advanced pore size distribution instrument (Micromeritics Instrument Corp., Norcross, Georgia, USA). NLDFT surface area is typically expressed in meters (m²). 2 / g is the unit of measurement. The NLDFT advanced pore size distribution technique uses up to two inert gases, such as nitrogen and carbon dioxide, to measure the amount of gas adsorbed on a material and can be used to determine the accessible surface area of ​​the material.

[0041] "NLDFT pore volume" refers to the total specific pore volume of a material measured using a dual isotherm NLDFT advanced pore size distribution instrument (Micromeritics Instrument Corp., Norcross, Georgia, USA). NLDFT pore volume is typically expressed in cm³. 3 / g is the unit of measurement. The NLDFT advanced pore size distribution technique uses up to two inert gases, such as nitrogen and carbon dioxide, to measure the amount of gas adsorbed on the material and can be used to determine the total pore volume of the material.

[0042] Surprisingly, it was found that carbon catalysts with a large number of mesopores in the range of 2-50 nm and a total pore volume of at least 0.45 ml / g resulted in higher conversion rates in the phosgene reaction section, which is equivalent to higher activity, slower deactivation, and longer catalyst / equipment life. This method can improve the yield relative to the chlorine used, has good heat transfer performance, and reduces the formation of carbon tetrachloride.

[0043] Unbound by this theory, it is believed that due to the large number of mesopores, the mass transfer restriction inside the catalyst particles is minimized, thereby reducing micropore loss. The main reaction occurs on the high surface area, so the catalyst has higher activity over time and is detected as having a lower deactivation rate.

[0044] Carbon materials with high to medium porosity can be prepared by modifying activated carbon based on natural products or by producing synthetic carbon, for example, through pyrolysis and activated carbon aerogels. Some carbon materials can be considered as monolithic carbon.

[0045] The carbon material used as the catalyst of the present invention comprises a pore structure including micropores, mesopores and total pore volume, which is generally described as a fraction (percentage) of the total pore volume present in micropores or mesopores or both, wherein at least 50% of the total pore volume is present in mesopores, up to 50% of the total pore volume is located in micropores, and less than 40% of the total pore volume is located in pores larger than 20 nm.

[0046] Optimized mixing of micropores and mesopores in carbon materials helps improve their catalytic performance. The pore structure can be customized to suit the needs of various phosgenation methods. The customized pore structure is regularly distributed on the catalyst particles.

[0047] Therefore, the volume fraction of mesopores is at least 50% of the total pore volume. Preferably, the carbon material contains a porous structure, wherein 50% to 90% of the total pore volume is contained in mesopores and 10% to 50% of the total pore volume is contained in micropores. More preferably, the carbon material contains a porous structure, wherein 50% to 80% of the total pore volume is located in mesopores and 20% to 50% of the total pore volume is located in micropores. Even more preferably, the carbon material contains a porous structure, wherein 60% to 80% of the total pore volume is located in mesopores and 20% to 40% of the total pore volume is located in micropores. Most preferably, the carbon material contains a porous structure, wherein 65% to 80% of the total pore volume is located in mesopores and 20% to 35% of the total pore volume is located in micropores.

[0048] In any other variant of the carbon material described above, the carbon material does not have a large volume of pores larger than 30 nm, preferably not a large volume of pores larger than 20 nm. For example, the carbon material contains less than 40%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, less than 2.5%, or even less than 1% of the total pore volume in pores larger than 20 nm.

[0049] The porosity of carbon materials helps to improve their catalytic performance. Preferably, the carbon material according to this method comprises pores in the 2-50 nm range with a pore volume of at least 0.45 ml / g, more preferably at least 0.5 ml / g, more preferably at least 0.6 ml / g, and most preferably at least 0.65 ml / g. Preferably, the carbon material comprises pores in the 2 nm-50 nm range with a pore volume ranging from about 0.45 ml / g to about 3.0 ml / g, more preferably from about 0.5 ml / g to about 2.5 ml / g, more preferably from about 0.6 ml / g to about 2.0 ml / g, and most preferably from about 0.65 ml / g to about 1.5 ml / g.

[0050] In preferred alternatives, the carbon material comprises at least 4.00 ml / g, at least 3.75 ml / g, at least 3.50 ml / g, at least 3.25 ml / g, at least 3.00 ml / g, at least 2.75 ml / g, at least 2.50 ml / g, at least 2.25 ml / g, at least 2.00 ml / g, at least 1.90 ml / g, at least 1.80 ml / g, at least 1.70 ml / g, at least 1.60 ml / g, at least 1.50 ml / g, at least 1.40 ml / g, at least 1.30 ml / g, at least 1.20 ml / g, at least 1.10 ml / g, at least 1.00 ml / g, at least 0.85 ml / g, at least 0.80 ml / g, at least 0.75 ml / g, at least 0.70 ml / g, at least 0.65 ml / g, at least 0.60 ml / g, and at least 0.55 ml / g. Total pore volume (measured by nitrogen adsorption) of at least 0.50 ml / g. For example, total pore volume (measured by nitrogen adsorption) of 0.52 ml / g, 0.57 ml / g, 0.62 ml / g, 0.67 ml / g, 0.72 ml / g, 0.77 ml / g, 0.82 ml / g, 0.87 ml / g, 0.92 ml / g, 0.97 ml / g, 1.02 ml / g, 1.07 ml / g, or 1.12 ml / g.

[0051] Preferably, the carbon material contains a total pore volume (measured by nitrogen adsorption) in the range of 0.5 ml / g to 2.25 ml / g, more preferably in the range of 0.55 ml / g to 1.75 ml / g, more preferably in the range of 0.65 ml / g to 1.35 ml / g, even more preferably in the range of 0.67 ml / g to 1.10 ml / g, and most preferably in the range of 0.68 ml / g to 1.0 ml / g.

[0052] The disclosed carbon material also includes a high surface area. Not wishing to be bound by theory, it is believed that this high surface area may at least partially contribute to its superior catalytic performance. Therefore, the carbon material has a surface area of ​​at least 100 μm. 2 / g, at least 300 m 2 / g, at least 500 m 2 / g, at least 1000 m 2 / g, at least 1500 m 2 / g, at least 2000 m 2 / g, at least 2400 m 2 / g, at least 2500 m 2 / g, at least 2750 m 2 / g or at least 3000 m 2The BET specific surface area is approximately 100 m² / g. Preferably, the BET specific surface area ranges from approximately 100 m² / g. 2 / g to approximately 3000 m 2 / g, more preferably about 500 m 2 / g to approximately 2500 m 2 / g, more preferably about 600 m 2 / g to approximately 2000 m 2 / g, the optimal value is approximately 600 m 2 / g to approximately 2000 m 2 / g.

[0053] For example, carbon materials can be activated.

[0054] The carbon material contains low total TXRF impurities. Therefore, it is preferable that the total TXRF impurity content (measured by total internal reflection X-ray fluorescence) of all other TXRF elements in the carbon material is less than 1000 ppm. More preferably, the total TXRF impurity content of all other TXRF elements in the carbon material is less than 800 ppm, less than 500 ppm, less than 300 ppm, less than 200 ppm, less than 150 ppm, less than 100 ppm, less than 50 ppm, less than 25 ppm, less than 10 ppm, less than 5 ppm, or less than 1 ppm.

[0055] Preferably, the carbon material is a pyrolytically dried polymer gel, a pyrolytic polymer freeze gel, a pyrolytic polymer dry gel, a pyrolytic polymer aerogel, an activated and dried polymer gel, an activated polymer freeze gel, an activated polymer dry gel, or an activated polymer aerogel.

[0056] Preferably, the carbon material contains elements with atomic numbers from 11 to 92 with a total impurity content of less than 500 ppm, as measured by total reflectance X-ray fluorescence. More preferably, the carbon material contains elements with atomic numbers from 11 to 92 with a total impurity content of less than 100 ppm, as measured by total reflectance X-ray fluorescence.

[0057] In addition to low levels of unwanted TXRF impurities, the carbon materials produced by this method can also have high total carbon content.

[0058] In addition to carbon, carbon materials may also include oxygen, hydrogen, and nitrogen. Preferably, the carbon material contains at least 75% carbon, more preferably at least 80% carbon, more preferably at least 85% carbon, more preferably at least 90% carbon, even more preferably at least 95% carbon, even more preferably at least 96% carbon, further more preferably at least 97% carbon, more preferably at least 98% carbon, or most preferably at least 99% carbon (by weight).

[0059] Preferably, the carbon material contains less than 10% oxygen, less than 5% oxygen, less than 3.0% oxygen, less than 2.5% oxygen, less than 1% oxygen, or less than 0.5% oxygen (by weight).

[0060] Preferably, the carbon material contains less than 10% hydrogen, less than 5% hydrogen, less than 2.5% hydrogen, less than 1% hydrogen, less than 0.5% hydrogen, or less than 0.1% hydrogen (by weight).

[0061] Preferably, the carbon material contains less than 5% nitrogen, less than 2.5% nitrogen, less than 1% nitrogen, less than 0.5% nitrogen, less than 0.25% nitrogen, or less than 0.01% nitrogen (by weight).

[0062] The oxygen, hydrogen, and nitrogen content of the disclosed carbon materials can be determined through combustion analysis. Techniques for determining elemental composition through combustion analysis are well known in the art.

[0063] This method can provide the total ash content of carbon materials, which may affect the catalytic performance of carbon materials in some cases.

[0064] Therefore, the ash content of carbon materials is in the range of 0.1% to 0.001% by weight ash, for example, the ash content of carbon materials is less than 0.1%, less than 0.08%, less than 0.05%, less than 0.03%, less than 0.025%, less than 0.01%, less than 0.0075%, less than 0.005%, or less than 0.001%.

[0065] Preferably, the ash content of the carbon material is less than 0.03% as calculated based on total internal reflection X-ray fluorescence data. More preferably, the ash content of the carbon material is less than 0.01% as calculated based on total internal reflection X-ray fluorescence data.

[0066] Preferably, the carbon material contains less than 500 ppm of total TXRF impurities and less than 0.08% ash. More preferably, the carbon material contains less than 300 ppm of total TXRF impurities and less than 0.05% ash. More preferably, the carbon material contains less than 200 ppm of total TXRF impurities and less than 0.05% ash. More preferably, the carbon material contains less than 200 ppm of total TXRF impurities and less than 0.025% ash. More preferably, the carbon material contains less than 100 ppm of total TXRF impurities and less than 0.02% ash. Most preferably, the carbon material contains less than 50 ppm of total TXRF impurities and less than 0.01% ash.

[0067] The amount of a single TXRF impurity present in the carbon material obtained from the embodiments of the provided method can be determined by proton-induced X-ray emission or total internal reflection X-ray fluorescence, respectively. A single TXRF impurity may affect the overall catalytic performance of the produced carbon material in different ways. Therefore, preferably, the sodium level present in the carbon material is less than 1000 ppm, more preferably less than 500 ppm, even more preferably less than 100 ppm, even more preferably less than 50 ppm, further more preferably less than 10 ppm, and most preferably less than 1 ppm.

[0068] As mentioned above, the content of other impurities (such as hydrogen, oxygen and / or nitrogen) can typically be less than 10% to less than 0.01%.

[0069] Preferably, the carbon material contains unwanted TXRF impurities that are close to or below the detection limit of total reflectance X-ray fluorescence analysis. For example, carbon materials contain less than 50 ppm sodium, less than 15 ppm magnesium, less than 10 ppm aluminum, less than 8 ppm silicon, less than 4 ppm phosphorus, less than 3 ppm sulfur, less than 3 ppm chlorine, less than 2 ppm potassium, less than 3 ppm calcium, less than 2 ppm scandium, less than 1 ppm titanium, less than 1 ppm vanadium, less than 0.5 ppm chromium, less than 0.5 ppm manganese, less than 0.5 ppm iron, less than 0.25 ppm cobalt, less than 0.25 ppm nickel, less than 0.25 ppm copper, less than 0.5 ppm zinc, less than 0.5 ppm gallium, less than 0.5 ppm germanium, less than 0.5 ppm arsenic, less than 0.5 ppm selenium, less than 1 ppm bromine, less than 1 ppm rubidium, less than 1.5 ppm strontium, less than 2 ppm yttrium, less than 3 ppm zirconium, less than 2 ppm niobium, less than 4 ppm molybdenum, less than 4 ppm technetium, less than 7 Rubidium less than ppm, rhodium less than 6 ppm, palladium less than 6 ppm, silver less than 9 ppm, cadmium less than 6 ppm, indium less than 6 ppm, tin less than 5 ppm, antimony less than 6 ppm, tellurium less than 6 ppm, iodine less than 5 ppm, cesium less than 4 ppm, barium less than 4 ppm, lanthanum less than 3 ppm, cerium less than 3 ppm, praseodymium less than 2 ppm, neodymium less than 2 ppm, promethium less than 1.5 ppm, samarium less than 1 ppm, europium less than 1 ppm, gadolinium less than 1 ppm, terbium less than 1 ppm, dysprosium less than 1 ppm, holmium less than 1 ppm, erbium less than 1 ppm, thulium less than 1 ppm, ytterbium less than 1 ppm, lutetium less than 1 ppm, hafnium less than 1 ppm, tantalum less than 1 ppm, tungsten less than 1 ppm, less than 1.5 ppm Rhenium less than ppm, osmium less than 1 ppm, iridium less than 1 ppm, platinum less than 1 ppm, silver less than 1 ppm, mercury less than 1 ppm, thallium less than 1 ppm, lead less than 1 ppm, bismuth less than 1.5 ppm, thorium less than 2 ppm, or uranium less than 4 ppm.

[0070] Alternatively, preferably, the carbon material contains less than 100 ppm sodium, less than 300 ppm silicon, less than 50 ppm sulfur, less than 100 ppm calcium, less than 20 ppm iron, less than 10 ppm nickel, less than 140 ppm copper, less than 5 ppm chromium, and less than 5 ppm zinc, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0071] Alternatively, preferably, the carbon material contains less than 50 ppm of sodium, less than 30 ppm of sulfur, less than 100 ppm of silicon, less than 50 ppm of calcium, less than 10 ppm of iron, less than 5 ppm of nickel, less than 20 ppm of copper, less than 2 ppm of chromium, and less than 2 ppm of zinc.

[0072] Alternatively, preferably, the carbon material contains less than 50 ppm of sodium, less than 50 ppm of silicon, less than 30 ppm of sulfur, less than 10 ppm of calcium, less than 2 ppm of iron, less than 1 ppm of nickel, less than 1 ppm of copper, less than 1 ppm of chromium, and less than 1 ppm of zinc.

[0073] Furthermore, it is even more preferred that the carbon material contains less than 100 ppm of sodium, less than 50 ppm of magnesium, less than 50 ppm of aluminum, less than 10 ppm of sulfur, less than 10 ppm of chlorine, less than 10 ppm of potassium, less than 1 ppm of chromium, and less than 1 ppm of manganese.

[0074] Preferably, the carbon material contains less than 10 ppm of iron.

[0075] Preferably, the carbon material contains less than 3 ppm of nickel.

[0076] Preferably, the carbon material contains less than 30 ppm of sulfur.

[0077] Preferably, the carbon material contains less than 1 ppm of chromium.

[0078] Preferably, the carbon material contains less than 1 ppm of copper.

[0079] Preferably, the carbon material contains less than 1 ppm of zinc.

[0080] The following carbon materials can be used in the methods of this invention: carbon materials include ultrapure, amorphous, and crystalline carbon materials. Examples of carbon materials include, but are not limited to, activated carbon, pyrolytic dried polymer gels, pyrolytic polymer freeze gels, pyrolytic polymer dry gels, pyrolytic polymer aerogels, activated dried polymer gels, activated polymer freeze gels, activated polymer dry gels, activated polymer aerogels, activated polymer aerogels, etc., as described in WO 2012 / 092210.

[0081] A common method for producing carbon materials that can be used as catalysts in this invention is to pyrolyze existing carbon-containing materials (e.g., coconut fiber or tire rubber). This results in carbon materials with relatively low surface areas, which can then be overactivated to produce materials with the surface area and porosity required for the desired application.

[0082] Activated carbon materials can also be prepared through chemical activation, for example, by treating carbon-containing materials with acids, alkalis or salts (such as phosphoric acid, potassium hydroxide, sodium hydroxide, zinc chloride, etc.) and then heating them to generate activated carbon materials.

[0083] The preferred carbon materials are pyrolytic polymer aerogels or active polymer aerogels, the production and product characteristics of which are described in WO 2012 / 092210.

[0084] According to WO 2012 / 092210, one method for producing such high surface area activated carbon materials is to prepare a synthetic polymer from a carbon-containing organic component (e.g., a polymer gel). Using existing organic materials, the synthetically prepared polymer is dried (e.g., by evaporation or freeze-drying), pyrolyzed, and activated to produce an activated carbon material (e.g., an aerogel or dry gel). Compared to the conventional methods described above, the inherent porosity of the synthetically prepared polymer results in a higher method yield because less material is lost in the activation step.

[0085] A preferred method for producing carbon materials includes:

[0086] a) Combining solvent, catalyst, first monomer, and second monomer to form a reaction mixture;

[0087] b) Maintain the reaction mixture at a holding temperature sufficient to copolymerize the first and second monomers to form a resin mixture;

[0088] c) Heating the resin mixture at a curing temperature to form a polymer composition comprising a solvent and a polymer formed by copolymerizing a first monomer and a second monomer, wherein the solvent concentration in the polymer composition is at least 40% by weight based on the total weight of the polymer composition; and

[0089] d) Pyrolyze the polymer composition at a pyrolysis temperature to substantially remove the solvent and pyrolyze the polymer to produce carbon materials.

[0090] Another preferred method includes:

[0091] a) Combining solvent, catalyst, first monomer and second monomer to generate a reaction mixture, and maintaining the reaction mixture at the reaction temperature for a period of time;

[0092] b) The reaction mixture is maintained at a holding temperature sufficient to copolymerize the first and second monomers to produce a resin mixture;

[0093] c) Heating the resin mixture to a curing temperature to form a polymer composition comprising a solvent and a polymer formed by copolymerizing a first monomer and a second monomer;

[0094] d) Pyrolyzing the polymer composition at a pyrolysis temperature, thereby substantially removing the solvent and pyrolyzing the polymer to produce carbonaceous materials; and

[0095] e) Optionally, the carbon material is activated at an activation temperature to increase the surface area and pore volume to the desired level to produce a high-performance carbon material.

[0096] Typically, the method according to the invention can be carried out in any multi-tube reactor suitable for producing phosgene by gas-phase reaction of carbon monoxide and chlorine in the presence of a carbon catalyst.

[0097] For example, International Patent Application WO 03 / 072273 discloses a typical phosgene reactor that can be used in the method of the present invention. The reactor has a bundle of contact tubes that are sealed parallel to each other at the bottom of the upper and lower tubes along the longitudinal direction of the reactor. At both ends of the reactor, shrouds are provided, in which gas distributors are arranged. A liquid heat exchange medium is used in the space between the contact tubes, with deflectors arranged perpendicular to the longitudinal direction. In the open areas, the reactor has no piping because in these areas, due to the transition of the coolant flow from transverse to longitudinal, insufficient cooling of the contact tubes is possible. Nozzles or partially annular channels are provided for supplying and dissipating the heat exchange medium. Compensators can be optionally used on the reactor shell to compensate for thermal stress.

[0098] A suitable reactor can be divided into at least two cooling zones along the longitudinal direction of the contact tube, these zones being separated from each other, for example, by an intermediate bottom partition. Different heat carriers can be used for different cooling zones, and their selection can be adjusted according to the thermal conditions of each cooling zone. It is preferable to use the same heat carrier. For example, in this case, a boiler can be used for cooling in a particularly high-calorific-value zone, while liquid cooling can be used in another cooling zone. In the case of boiler cooling, it is preferable not to provide deflector plates or to provide specially designed deflector plates to prevent the accumulation of rising bubbles.

[0099] Different substances and mixtures of substances can be used as fluid heat carriers, for example, those suitable for dissipating the heat of reaction due to their heat capacity or enthalpy of vaporization. Typically, liquid heat carriers are used, such as water, dibenzyltoluene (Marlotherm), or monochlorobenzene.

[0100] The length L of the reactor contact tube can be in the range of 1.5-12 m, preferably 2.5-8 m.

[0101] A suitable reactor according to the method of the present invention can be equipped with 1,000 to 10,000 contact tubes and can be cylindrical with an inner diameter preferably 0.3-6 m, more preferably 2-5 m, and particularly 2.5-4 m.

[0102] In the reactor, a bundle (i.e., a large number of contact tubes) is arranged parallel to each other along the longitudinal direction of the reactor.

[0103] The wall thickness of each contact tube is preferably between 2.0 and 4.0 mm, particularly between 2.5 and 3.0 mm, and the inner diameter of the tube is preferably between 20 and 90 mm, more preferably between 30 and 50 mm.

[0104] The contact tube is made of a corrosion-resistant material, such as stainless steel, preferably duplex steel 1.4462, stainless steel 1.4571 or stainless steel 1.4541, or also made of nickel-based alloys or nickel. Preferably, the bottom of the tube or the entire reactor is made of the above-mentioned materials, especially duplex steel or stainless steel.

[0105] However, the reactor shell and base can also be made of cheaper metals and metal alloys, such as black steel. Then, the parts in contact with the reactants can be plated with a protective layer made of high-quality materials.

[0106] Both ends of the reactor are enclosed by hoods. One hood feeds the reaction mixture into the contact tube, while the product stream is removed through the hood at the other end of the reactor.

[0107] In the hood supplying the reaction mixture, a gas distributor, preferably in the form of a plate (especially a perforated plate), is preferred to distribute the airflow evenly.

[0108] The contact tube is filled with a solid catalyst. The interstitial volume of the catalyst filling the contact tube is preferably 0.33 to 0.6, especially 0.33 to 0.45. The interstitial volume refers to the amount of catalyst packed, wherein the solid catalyst is assumed to be a solid body. The porosity of the catalyst body itself (e.g., 50%) is not taken into account.

[0109] Preferably, the surface load in the method of the present invention is 0.5 kg phosgene / m 2 s to 6 kg phosgene / m 2 Within the range of s, more preferably within 0.7 kg phosgene / m 2 s to 5 kg phosgene / m 2 Within the range of s, or even more preferably within 0.7 kg phosgene / m 2 s to 4 kg phosgene / m 2 Within the range of s, it is particularly preferred to be 0.8 kg phosgene / m 2 s to 3.5 kg phosgene / m 2 Within the range of s.

[0110] The areal load of existing reactors can be increased by adjusting operating parameters, particularly by increasing the volumetric flow rate of the reactants. However, given the areal load, newly designed reactors can already be constructively optimized in their operation.

[0111] An increase in surface load can be achieved by reducing the number of contact tubes in the reactor and correspondingly increasing their length. For example, halving the number of contact tubes with the same diameter will double both the surface load and the tube length. Consequently, the reactors become smaller, i.e., their diameters are smaller for a given GHSV, which is advantageous in terms of both production and cooling of the contact tubes. Pressure loss in the contact tubes increases due to the higher gas velocity and longer fill length, but this also results in better distribution of the feed flow across all contact tubes.

[0112] With the same phosgene capacity and catalyst quantity, and with the number of pipes remaining unchanged, surface load can also be achieved by reducing the diameter of a single contact pipe and correspondingly extending the contact pipe.

[0113] Of course, a combination of these two measures can also be considered, namely reducing the number of pipes and reducing the diameter of individual pipes.

[0114] Preferably, the stoichiometric excess of carbon monoxide in the feed stream of the method of the present invention is 0.001-50 mol%, thus ensuring almost complete conversion of chlorine. If fluctuations in the chlorine concentration in the chlorine input stream must be anticipated, a higher excess of carbon monoxide should be selected; however, generally, for cost reasons, the lowest possible excess of carbon monoxide should be selected as long as complete conversion of chlorine is still guaranteed.

[0115] The feed stream is preferably supplied at an absolute pressure in the range of 0.5-20 bara. Particularly preferred is that the feed stream is supplied at overpressure, for example, at an absolute pressure of 3-7 bara. The higher the pressure of the reaction mixture at the reactor outlet, the greater the degree to which the phosgene contained in the reaction mixture can be condensed. Preferably, the pressure of the reaction mixture at the reactor outlet remains high enough that the phosgene can be at least partially condensed with cooling water.

[0116] Furthermore, an object of the present invention is to provide a novel reaction mixture for generating phosgene. In particular, it is necessary to provide a novel reaction mixture containing a catalyst for producing phosgene that exhibits higher catalytic activity and longer catalytic lifetime compared to commercially available catalysts, and reduces the formation of CCl4 during phosgene preparation.

[0117] Surprisingly, the reaction mixture used to prepare phosgene can improve process efficiency. In particular, the catalyst contained herein has higher catalytic activity and longer catalytic lifetime compared to commercially available catalysts, and reduces the formation of CCl4 during phosgene preparation.

[0118] Therefore, the present invention also relates to a reaction mixture for preparing phosgene, the mixture comprising:

[0119] (i) A catalyst for preparing phosgene, said catalyst comprising a porous material containing carbon, micropores, and mesopores, wherein the micropores have a pore size less than 2 nm, the mesopores have a pore size ranging from 2 to 50 nm, and the mesopore volume of the porous material is at least 0.45 ml / g; and

[0120] (ii) A gas stream G containing carbon monoxide (CO) and chlorine (Cl2).

[0121] The pore size of the micropores is preferably determined according to DIN 66135-2. The pore size of the mesopores is preferably determined according to DIN 66134. The volume of the mesopores in the porous material is preferably determined using the double isotherm nonlocal density functional theory (NLDFT) advanced pore size distribution (PSD) technique. More preferably, the pore size of the micropores is determined according to DIN 66135-2, the pore size of the mesopores is determined according to DIN 66134, and the volume of the mesopores in the porous material is determined using the double isotherm nonlocal density functional theory (NLDFT) advanced pore size distribution (PSD) technique.

[0122] Preferably, the ratio of the mesopore volume to the micropore volume of the porous material of catalyst (i) is at least 1:1, more preferably in the range of 1.1:1 to 6:1, more preferably in the range of 1.15:1 to 5:1, and even more preferably in the range of 1.2:1 to 4:1. It is even more preferable to determine the mesopore volume and micropore volume of the porous material using the dual isotherm NLDFT advanced PSD technique.

[0123] Preferably, the ratio of the mesopore volume of the porous material of catalyst (i) to the total pore volume of the porous material of catalyst (i) is at least 0.5:1, preferably in the range of 0.5:1 to 0.9:1, more preferably in the range of 0.55:1 to 0.85:1, more preferably in the range of 0.6:1 to 0.8:1, and even more preferably in the range of 0.65:1 to 0.8:1. More preferably, the mesopore volume and the total pore volume of the porous material are determined according to the dual isotherm NLDFT advanced PSD technology.

[0124] The preferred catalyst (i) has a mesopore volume of at least 0.5 ml / g in its porous material.

[0125] Regarding the total pore volume of the porous material of catalyst (i), it is preferably in the range of 0.5-2.25 ml / g, more preferably in the range of 0.55-1.75 ml / g, and even more preferably in the range of 0.65-1.70 ml / g. Determining the total pore volume of the porous material using the dual isotherm NLDFT advanced PSD technique is even more preferred.

[0126] The total pore volume of the preferred catalyst (i) is less than or equal to 40%, more preferably less than or equal to 30%, more preferably less than or equal to 25%, more preferably less than or equal to 20%, more preferably less than or equal to 15%, more preferably less than or equal to 10%, more preferably less than or equal to 5%, more preferably less than or equal to 2.5%, and more preferably less than or equal to 1% located in mesopores with a pore size greater than 20 nm.

[0127] The mesopore volume of the porous material of catalyst (i) is preferably in the range of 0.50-0.54 ml / g, more preferably in the range of 0.51-0.53 ml / g, and the ratio of the mesopore volume of the porous material of catalyst (i) to the total pore volume of the porous material of catalyst (i) is in the range of 0.70:1 to 0.75:1, more preferably in the range of 0.72:1 to 0.74:1. More preferably, the mesopore volume and the total pore volume of the porous material are determined according to the dual isotherm NLDFT advanced PSD technique.

[0128] Alternatively, the mesopore volume of the porous material of catalyst (i) is preferably in the range of 0.64-0.70 ml / g, more preferably in the range of 0.65-0.67 ml / g, and the ratio of the mesopore volume of the porous material of catalyst (i) to the total pore volume of the porous material of catalyst (i) is in the range of 0.72:1 to 0.78:1, more preferably in the range of 0.73:1 to 0.76:1. As mentioned above, the mesopore volume and the total pore volume of the porous material are more preferably determined according to the dual isotherm NLDFT advanced PSD technology.

[0129] In the context of this invention, preferably, the micropore volume of the porous material of the catalyst (i) (more preferably determined according to the dual isotherm NLDFT advanced PSD technology) is at most 0.7 ml / g, and more preferably at most 0.6 ml / g.

[0130] Regarding the BET specific surface area of ​​the porous material of catalyst (i), it is preferably at least 500 m². 2 / g, more preferably 500-2500 m 2 Within the range of / g, more preferably within 550-1800 m 2 Within the range of / g, more preferably within the range of 600-1500 m 2 Within the range of / g.

[0131] Regarding the total specific surface area of ​​the porous material of catalyst (i), measured using the dual isotherm NLDFT advanced PSD technique, it is preferably at least 600 m². 2 / g, more preferably 650-2000 m 2 Within the range of / g, more preferably 700-1800 m 2 Within the range of / g.

[0132] The specific surface area of ​​the porous material of catalyst (i) measured by dual isotherm NLDFT advanced PSD technology is preferably 70-250 m². 2 Within the range of / g, more preferably within 80-170 m 2 Within the range of / g.

[0133] Preferably, the ratio of the specific surface area caused by the mesopores of the porous material of catalyst (i) to the total specific surface area of ​​the porous material of catalyst (i) is in the range of 0.07:1 to 0.40:1, and more preferably in the range of 0.07:1 to 0.20:1.

[0134] The porous material of catalyst (i) is preferably pyrolytic carbon aerogel.

[0135] The porous material of catalyst (i) is preferably an active pyrolytic carbon aerogel.

[0136] The porous material of the catalyst (i) is preferably composed of carbon in a manner of 99% to 100% by weight, more preferably 99.5% to 100% by weight, and even more preferably 99.9% to 100% by weight.

[0137] The porous material of the preferred catalyst (i) is composed of oxygen in a weight of less than or equal to 0.5%.

[0138] The porous material of the preferred catalyst (i) is composed of hydrogen in less than or equal to 0.5% by weight, and more preferably less than or equal to 0.1% by weight.

[0139] The porous material of the preferred catalyst (i) is composed of nitrogen in a weight of less than or equal to 0.01%.

[0140] Preferably, based on total internal reflection X-ray fluorescence data, and calculated by weight of the porous material, the ash content of the porous material of the catalyst (i) is less than or equal to 0.1 wt%, more preferably less than or equal to 0.08 wt%, more preferably less than or equal to 0.05 wt%, even more preferably less than or equal to 0.03 wt%, more preferably less than or equal to 0.025 wt%, more preferably less than or equal to 0.01 wt%, more preferably less than or equal to 0.0075 wt%, more preferably less than or equal to 0.005 wt%, and even more preferably less than or equal to 0.001 wt%.

[0141] Preferably, the porous material of the catalyst (i) has a total impurity content of elements with atomic numbers from 11 to 92 as measured by total reflection X-ray fluorescence (TXRF) of less than 500 ppm, more preferably less than 300 ppm, more preferably less than 200 ppm, and more preferably less than 100 ppm.

[0142] Preferably, the porous material of catalyst (i) comprises a total TXRF impurity content of less than or equal to 500 ppm and an ash content of less than or equal to 0.08% by weight, based on the weight of the porous material. More preferably, the porous material of catalyst (i) comprises a total TXRF impurity content of less than or equal to 300 ppm and an ash content of less than 0.05% by weight, based on the weight of the porous material. More preferably, the porous material of catalyst (i) comprises a total TXRF impurity content of less than or equal to 200 ppm and an ash content of less than 0.05% by weight, based on the weight of the porous material. More preferably, the porous material of catalyst (i) comprises a total TXRF impurity content of less than or equal to 200 ppm and an ash content of less than 0.025% by weight, based on the weight of the porous material. More preferably, the porous material of catalyst (i) comprises a total TXRF impurity content of less than or equal to 100 ppm and an ash content of less than 0.02% by weight, based on the weight of the porous material. More preferably, the porous material of the catalyst (i) contains a total TXRF impurity content of less than or equal to 50 ppm and an ash content of less than 0.01% by weight, based on the weight of the porous material.

[0143] The amount of individual TXRF impurities present in the porous material contained in catalyst (i) can be determined by proton-induced X-ray emission or total internal reflection X-ray fluorescence, respectively. Individual TXRF impurities can affect the overall catalytic performance of catalyst (i) containing the porous material in different ways. Therefore, it is preferred that the sodium content in the porous material is less than or equal to 1000 ppm, less than or equal to 500 ppm, less than or equal to 100 ppm, less than or equal to 50 ppm, less than or equal to 10 ppm, or less than or equal to 1 ppm.

[0144] Preferably, the porous material contained in the catalyst (i) contains unwanted TXRF impurities at or below the detection limit of total reflectance X-ray fluorescence analysis. For example, the porous material preferably contains less than or equal to 50 ppm sodium, less than or equal to 15 ppm magnesium, less than or equal to 10 ppm aluminum, less than or equal to 8 ppm silicon, less than or equal to 4 ppm phosphorus, less than or equal to 3 ppm sulfur, less than or equal to 3 ppm chlorine, less than or equal to 2 ppm potassium, less than or equal to 3 ppm calcium, less than or equal to 2 ppm scandium, less than or equal to 1 ppm titanium, less than or equal to 1 ppm vanadium, less than or equal to 0.5 ppm chromium, less than or equal to 0.5 ppm manganese, less than or equal to 0.5 ppm iron, less than or equal to 0.25 ppm cobalt, less than or equal to 0.25 ppm nickel, less than or equal to 0.25 ppm copper, and less than or equal to 0.5 ppm copper. Zinc ppm, Gallium ≤ 0.5 ppm, Germanium ≤ 0.5 ppm, Arsenic ≤ 0.5 ppm, Selenium ≤ 0.5 ppm, Bromine ≤ 1 ppm, Rubidium ≤ 1 ppm, Strontium ≤ 1.5 ppm, Yttrium ≤ 2 ppm, Zirconium ≤ 3 ppm, Niobium ≤ 2 ppm, Molybdenum ≤ 4 ppm, Technetium ≤ 4 ppm, Rubidium ≤ 7 ppm, Rhodium ≤ 6 ppm, Palladium ≤ 6 ppm, Silver ≤ 9 ppm, Cadmium ≤ 6 ppm, Indium ≤ 6 ppm, Tin ≤ 5 ppm, Antimony ≤ 6 ppm, Tellurium ≤ 6 ppm, Iodine ≤ 5 ppm, Cesium ≤ 4 ppm, Barium ≤ 4 ppm, Lanthanum ≤ 3 ppm, Cerium ≤ 3 ppm, Praseodymium ≤ 2 ppm, Neodymium ≤ 2 ppm, Promethium ≤ 1.5 ppm, ≤ 1 Samarium ppm, europium ≤ 1 ppm, gadolinium ≤ 1 ppm, terbium ≤ 1 ppm, dysprosium ≤ 1 ppm, holmium ≤ 1 ppm, erbium ≤ 1 ppm, thulium ≤ 1 ppm, ytterbium ≤ 1 ppm, lutetium ≤ 1 ppm, hafnium ≤ 1 ppm, tantalum ≤ 1 ppm, tungsten ≤ 1 ppm, rhenium ≤ 1.5 ppm, osmium ≤ 1 ppm, iridium ≤ 1 ppm, platinum ≤ 1 ppm, silver ≤ 1 ppm, mercury ≤ 1 ppm, thallium ≤ 1 ppm, lead ≤ 1 ppm, bismuth ≤ 1.5 ppm, thorium ≤ 2 ppm, uranium ≤ 4 ppm.

[0145] Preferably, the porous material of the catalyst (i) contains less than 100 ppm sodium, less than 300 ppm silicon, less than 50 ppm sulfur, less than 100 ppm calcium, less than 20 ppm iron, less than 10 ppm nickel, less than 140 ppm copper, less than 5 ppm chromium and less than 5 ppm zinc, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0146] Alternatively, the porous material of the preferred catalyst (i) contains less than 50 ppm sodium, less than 30 ppm sulfur, less than 100 ppm silicon, less than 50 ppm calcium, less than 10 ppm iron, less than 5 ppm nickel, less than 20 ppm copper, less than 2 ppm chromium and less than 2 ppm zinc, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0147] Alternatively, preferably, the porous material of the catalyst (i) contains less than 50 ppm sodium, less than 50 ppm silicon, less than 30 ppm sulfur, less than 10 ppm calcium, less than 2 ppm iron, less than 1 ppm nickel, less than 1 ppm copper, less than 1 ppm chromium and less than 1 ppm zinc, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0148] Alternatively, the porous material of the preferred catalyst (i) contains less than 100 ppm sodium, less than 50 ppm magnesium, less than 50 ppm aluminum, less than 10 ppm sulfur, less than 10 ppm chlorine, less than 10 ppm potassium, less than 1 ppm chromium and less than 1 ppm manganese, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0149] Preferably, the porous material of the catalyst (i) contains less than 10 ppm of iron, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0150] Preferably, the porous material of the catalyst (i) contains less than 3 ppm of nickel, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0151] Preferably, the porous material of the catalyst (i) contains less than 30 ppm of sulfur, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0152] Preferably, the porous material of the catalyst (i) contains less than 1 ppm of chromium, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0153] Preferably, the porous material of the catalyst (i) contains less than 1 ppm of copper, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0154] Preferably, the porous material of the catalyst (i) contains less than 1 ppm of zinc, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0155] The preferred catalyst (i) comprises 99-100% by weight, preferably 99.5-100% by weight, and more preferably 99.9-100% by weight of porous material. In other words, the preferred catalyst (i) is substantially composed of porous material, and more preferably composed of porous material.

[0156] More preferably, the catalyst (i) is a porous material.

[0157] The gas flow G is preferably composed of carbon monoxide and chlorine.

[0158] Furthermore, another object of the present invention is to provide an improved catalyst for the generation of phosgene. In particular, it is necessary to provide new catalysts for phosgene production that have higher catalytic activity and longer catalytic lifetime compared to commercially available catalysts, and reduce the formation of CCl4 during phosgene preparation.

[0159] Surprisingly, compared with commercially available catalysts, the catalyst for preparing phosgene according to the present invention has higher catalytic activity and longer catalytic lifetime, and reduces the formation of CCl4 during phosgene preparation.

[0160] Therefore, the present invention also relates to a catalyst for preparing phosgene, the catalyst comprising a porous material containing carbon, micropores and mesopores, wherein the micropores have a pore size of less than 2 nm and the mesopores have a pore size ranging from 2 to 50 nm, wherein the mesopore volume of the porous material is in the range of 0.50-0.54 ml / g, and the ratio of the mesopore volume of the porous material to the total pore volume of the porous material is in the range of 0.70:1 to 0.75:1, wherein 99-100% by weight of the porous material is composed of carbon.

[0161] The pore size of the micropores is preferably determined according to DIN 66135-2. The pore size of the mesopores is preferably determined according to DIN 66134. Preferably, the mesopore volume and total pore volume of the porous material are determined using the double isotherm nonlocal density functional theory (NLDFT) advanced pore size distribution (PSD) technique. More preferably, the pore size of the micropores is determined according to DIN 66135-2, the pore size of the mesopores is determined according to DIN 66134, and the mesopore volume and total pore volume of the porous material are determined using the double isotherm nonlocal density functional theory (NLDFT) advanced pore size distribution (PSD) technique.

[0162] Preferably, the mesopore volume of the porous material is in the range of 0.51-0.53 ml / g, and the ratio of the mesopore volume to the total pore volume of the porous material is in the range of 0.72:1 to 0.74:1.

[0163] Therefore, the present invention also relates to a catalyst for preparing phosgene, the catalyst comprising a porous material containing carbon, micropores and mesopores, wherein the micropores have a pore size of less than 2 nm and the mesopores have a pore size ranging from 2 to 50 nm, wherein the mesopore volume of the porous material is in the range of 0.64-0.70 ml / g, and the ratio of the mesopore volume of the porous material to the total pore volume of the porous material is in the range of 0.72:1 to 0.78:1, wherein 99-100% by weight of the porous material is composed of carbon.

[0164] The pore size of the micropores is preferably determined according to DIN 66135-2. The pore size of the mesopores is preferably determined according to DIN 66134. Preferably, the mesopore volume and total pore volume of the porous material are determined using the double isotherm nonlocal density functional theory (NLDFT) advanced pore size distribution (PSD) technique. More preferably, the pore size of the micropores is determined according to DIN 66135-2, the pore size of the mesopores is determined according to DIN 66134, and the mesopore volume and total pore volume of the porous material are determined using the double isotherm nonlocal density functional theory (NLDFT) advanced pore size distribution (PSD) technique.

[0165] Preferably, the mesopore volume of the porous material is in the range of 0.65-0.67 ml / g, and the ratio of the mesopore volume to the total pore volume of the porous material is in the range of 0.73:1 to 0.76:1.

[0166] The following preferred parameters / characteristics are related to the two catalysts mentioned above used for the preparation of phosgene.

[0167] Preferably, the ratio of the mesopore volume to the micropore volume of the porous material is at least 1:1, more preferably in the range of 1.1:1 to 6:1, even more preferably in the range of 1.15:1 to 5:1, even more preferably in the range of 1.2:1 to 4:1, and even more preferably the mesopore volume and the micropore volume of the porous material are determined according to the dual isotherm NLDFT advanced PSD technology.

[0168] In preferred porous materials, less than or equal to 40%, more preferably less than or equal to 30%, more preferably less than or equal to 25%, more preferably less than or equal to 20%, more preferably less than or equal to 15%, more preferably less than or equal to 10%, more preferably less than or equal to 5%, more preferably less than or equal to 2.5%, and more preferably less than or equal to 1% of the total pore volume are located in mesopores with a pore size greater than 20 nm.

[0169] Preferably, the micropore volume of the porous material, more preferably measured according to the dual isotherm NLDFT advanced PSD technique, is at most 0.7 ml / g, and even more preferably at most 0.6 ml / g.

[0170] The preferred porous material has a BET specific surface area of ​​at least 500 m². 2 / g, more preferably 500-2500 m 2 Within the range of / g, more preferably 550-1800 m 2 Within the range of / g, more preferably 600-1500 m 2 Within the range of / g.

[0171] Regarding the total specific surface area of ​​the porous material, measured using the dual isotherm NLDFT advanced PSD technique, it is preferably at least 600 m². 2 / g, more preferably 650-2000 m 2 Within the range of / g, more preferably 700-1800 m 2 Within the range of / g.

[0172] Regarding the specific surface area of ​​porous materials caused by mesopores, according to measurements using the dual isotherm NLDFT advanced PSD technique, it is preferably between 70-250 μm. 2 Within the range of / g, more preferably within 80-170 m 2 Within the range of / g.

[0173] Preferably, the ratio of the specific surface area of ​​the porous material caused by the mesopore to the total specific surface area of ​​the porous material is in the range of 0.07:1 to 0.40:1, more preferably in the range of 0.07:1 to 0.20:1.

[0174] The preferred porous material is pyrolytic carbon aerogel.

[0175] The preferred porous material is active pyrolytic carbon aerogel.

[0176] Preferably, the porous material is composed of carbon in 99.5% to 100% by weight, more preferably in 99.9% to 100% by weight.

[0177] The preferred porous material is composed primarily of carbon, and more preferably of carbon.

[0178] Preferably, the porous material consists of oxygen in a composition of less than or equal to 0.5% by weight.

[0179] The preferred porous material is composed of less than or equal to 0.5% by weight, and more preferably less than or equal to 0.1% by weight, of hydrogen.

[0180] The preferred porous material is composed of less than or equal to 0.01% by weight of nitrogen.

[0181] Preferably, the ash content of the porous material is less than or equal to 0.1 wt%, more preferably less than or equal to 0.08 wt%, more preferably less than or equal to 0.05 wt%, more preferably less than or equal to 0.03 wt%, even more preferably less than or equal to 0.025 wt%, more preferably less than or equal to 0.01 wt%, more preferably less than or equal to 0.0075 wt%, more preferably less than or equal to 0.005 wt%, more preferably less than or equal to 0.001 wt%, calculated based on the total internal reflection X-ray fluorescence data, according to the weight of the porous material.

[0182] Preferably, the porous material has a total impurity content of elements with atomic numbers between 11 and 92 as measured by total internal reflection X-ray fluorescence (TXRF) of less than or equal to 500 ppm, more preferably less than or equal to 300 ppm, more preferably less than or equal to 200 ppm, and even more preferably less than or equal to 100 ppm.

[0183] The preferred porous material comprises a total TXRF impurity content of less than or equal to 500 ppm based on the weight of the porous material, and an ash content of less than or equal to 0.08% by weight. More preferably, the porous material comprises a total TXRF impurity content of less than or equal to 300 ppm based on the weight of the porous material and an ash content of less than 0.05% by weight. More preferably, the porous material comprises a total TXRF impurity content of less than or equal to 200 ppm based on the weight of the porous material and an ash content of less than 0.05% by weight. More preferably, the porous material comprises a total TXRF impurity content of less than or equal to 200 ppm based on the weight of the porous material and an ash content of less than 0.025% by weight. More preferably, the porous material comprises a total TXRF impurity content of less than or equal to 100 ppm based on the weight of the porous material and an ash content of less than 0.02% by weight. More preferably, the porous material comprises a total TXRF impurity content of less than or equal to 50 ppm based on the weight of the porous material and an ash content of less than 0.01% by weight.

[0184] The amount of individual TXRF impurities present in the porous material can be determined by proton-induced X-ray emission or total internal reflection X-ray fluorescence, respectively. Individual TXRF impurities can affect the overall catalytic performance of the catalyst (i) containing the porous material in different ways. Therefore, it is preferred that the sodium level present in the porous material is less than or equal to 1000 ppm, less than or equal to 500 ppm, less than or equal to 100 ppm, less than or equal to 50 ppm, less than or equal to 10 ppm, or less than or equal to 1 ppm.

[0185] Preferably, the porous material contains unwanted TXRF impurities, each at or below the detection limit of total reflectance X-ray fluorescence analysis. For example, the porous material preferably contains less than or equal to 50 ppm sodium, less than or equal to 15 ppm magnesium, less than or equal to 10 ppm aluminum, less than or equal to 8 ppm silicon, less than or equal to 4 ppm phosphorus, less than or equal to 3 ppm sulfur, less than or equal to 3 ppm chlorine, less than or equal to 2 ppm potassium, less than or equal to 3 ppm calcium, less than or equal to 2 ppm scandium, less than or equal to 1 ppm titanium, less than or equal to 1 ppm vanadium, less than or equal to 0.5 ppm chromium, less than or equal to 0.5 ppm manganese, less than or equal to 0.5 ppm iron, less than or equal to 0.25 ppm cobalt, less than or equal to 0.25 ppm nickel, less than or equal to 0.25 ppm copper, and less than or equal to 0.5 ppm... Zinc ppm, gallium ≤ 0.5 ppm, germanium ≤ 0.5 ppm, arsenic ≤ 0.5 ppm, selenium ≤ 0.5 ppm, bromine ≤ 1 ppm, rubidium ≤ 1 ppm, strontium ≤ 1.5 ppm, yttrium ≤ 2 ppm, zirconium ≤ 3 ppm, niobium ≤ 2 ppm, molybdenum ≤ 4 ppm, technetium ≤ 4 ppm, rubidium ≤ 7 ppm, rhodium ≤ 6 ppm, palladium ≤ 6 ppm, silver ≤ 9 ppm, cadmium ≤ 6 ppm, indium ≤ 6 ppm, tin ≤ 5 ppm, antimony ≤ 6 ppm, tellurium ≤ 6 ppm, iodine ≤ 5 ppm, cesium ≤ 4 ppm, barium ≤ 4 ppm, lanthanum ≤ 3 ppm, cerium ≤ 3 ppm, praseodymium ≤ 2 ppm, neodymium ≤ 2 ppm, ≤ 1.5 ppm Promethium ppm, samarium ≤ 1 ppm, europium ≤ 1 ppm, gadolinium ≤ 1 ppm, terbium ≤ 1 ppm, dysprosium ≤ 1 ppm, holmium ≤ 1 ppm, erbium ≤ 1 ppm, thulium ≤ 1 ppm, ytterbium ≤ 1 ppm, lutetium ≤ 1 ppm, hafnium ≤ 1 ppm, tantalum ≤ 1 ppm, tungsten ≤ 1 ppm, rhenium ≤ 1.5 ppm, osmium ≤ 1 ppm, iridium ≤ 1 ppm, platinum ≤ 1 ppm, silver ≤ 1 ppm, mercury ≤ 1 ppm, thallium ≤ 1 ppm, lead ≤ 1 ppm, bismuth ≤ 1.5 ppm, thorium ≤ 2 ppm, uranium ≤ 4 ppm.

[0186] The preferred porous material contains less than 100 ppm sodium, less than 300 ppm silicon, less than 50 ppm sulfur, less than 100 ppm calcium, less than 20 ppm iron, less than 10 ppm nickel, less than 140 ppm copper, less than 5 ppm chromium and less than 5 ppm zinc, as determined by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0187] Alternatively, the preferred porous material contains less than 50 ppm sodium, less than 30 ppm sulfur, less than 100 ppm silicon, less than 50 ppm calcium, less than 10 ppm iron, less than 5 ppm nickel, less than 20 ppm copper, less than 2 ppm chromium, and less than 2 ppm zinc, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0188] Alternatively, the preferred porous material contains less than 50 ppm of sodium, less than 50 ppm of silicon, less than 30 ppm of sulfur, less than 10 ppm of calcium, less than 2 ppm of iron, less than 1 ppm of nickel, less than 1 ppm of copper, less than 1 ppm of chromium, and less than 1 ppm of zinc, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0189] Alternatively, the preferred porous material contains less than 100 ppm sodium, less than 50 ppm magnesium, less than 50 ppm aluminum, less than 10 ppm sulfur, less than 10 ppm chlorine, less than 10 ppm potassium, less than 1 ppm chromium, and less than 1 ppm manganese, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0190] Based on proton-induced X-ray emission or total internal reflection X-ray fluorescence measurements, the preferred porous material contains less than 10 ppm of iron.

[0191] The preferred porous material contains less than 3 ppm of nickel, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0192] The preferred porous material contains less than 30 ppm of sulfur, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0193] The preferred porous material contains less than 1 ppm of chromium, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0194] The preferred porous material contains less than 1 ppm of copper, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0195] The preferred porous material contains less than 1 ppm of zinc, as measured by proton-induced X-ray emission or total internal reflection X-ray fluorescence.

[0196] Preferably, 99-100% by weight of the catalyst, more preferably 99.5-100% by weight, and even more preferably 99.9-100% by weight, is composed of porous material. In other words, preferably the catalyst is substantially composed of porous material, more preferably composed of porous material. More preferably, the catalyst is a porous material.

[0197] Furthermore, the present invention also relates to the use of the catalyst according to the present invention for the preparation of phosgene.

[0198] Furthermore, the present invention relates to the use of the reaction mixture according to the present invention for the preparation of phosgene.

[0199] This invention relates to a catalyst (i) for preparing a reaction mixture for preparing phosgene according to the method of the invention, or a method for preparing a catalyst according to the invention, the method comprising:

[0200] a) Prepare a mixture comprising a solvent, a catalyst, a first monomer, and a second monomer;

[0201] b) Copolymerize the first and second monomers of the mixture obtained in a) to obtain a resin mixture;

[0202] c) Heating the resin mixture obtained according to b) at a curing temperature to obtain a polymer composition comprising a solvent and a polymer formed by copolymerizing a first monomer and a second monomer, wherein the solvent concentration in the polymer composition is at least 40% by weight based on the total weight of the polymer composition; and

[0203] d) Pyrolyze the polymer composition obtained according to c) at the pyrolysis temperature, thereby substantially removing the solvent and pyrolyzing the polymer to obtain the catalyst.

[0204] The present invention also relates to a catalyst (i) for preparing a reaction mixture for preparing phosgene according to the present invention, or a method for preparing the catalyst according to the present invention, the method comprising:

[0205] 1) Prepare a mixture containing a solvent, a catalyst, a first monomer, and a second monomer, and maintain the reaction at the reaction temperature for the specified time;

[0206] 2) The first and second monomers of the mixture according to 1) are copolymerized to obtain a resin mixture;

[0207] 3) Curing the resin mixture obtained according to 2) at a curing temperature to obtain a polymer composition comprising a solvent and a polymer formed by copolymerizing the first monomer and the second monomer according to 2);

[0208] 4) Pyrolyze the polymer composition obtained according to 3) at a pyrolysis temperature, thereby substantially removing the solvent and pyrolyzing the polymer to obtain a carbon material; and

[0209] 5) Optionally, the carbon material is activated at the activation temperature to increase the surface area and pore volume to the desired level, thereby obtaining a catalyst.

[0210] The preferred features described below are related to the methods described above.

[0211] Preferably, the first monomer is resorcinol and the second monomer is formaldehyde.

[0212] Preferably, the solvent comprises water and acetic acid, more preferably water and acetic acid.

[0213] The catalyst used in a) and / or 1) is preferably an ammonium acetate catalyst.

[0214] Furthermore, it is worth noting that the catalyst of the present invention can be prepared by changing the polymerization and gelation conditions (temperature, duration, etc.) according to the method described in WO 2012 / 092210 A1.

[0215] The following set of embodiments, as well as combinations of embodiments derived from the shown dependencies and reverse references, further illustrate the invention. It is particularly important to note that in each instance of reference to a series of embodiments, such as in the context of terms like "a reaction mixture of any one of embodiments 1 to 4," each embodiment within that scope is intended to explicitly disclose to those skilled in the art that the terminology should be understood by those skilled in the art as a synonym for "a reaction mixture of any one of embodiments 1, 2, 3, and 4." Furthermore, it should be explicitly stated that the following set of embodiments represents a suitable construct of the general description of preferred aspects of the invention, and therefore appropriately supports but does not imply the claims of the invention.

[0216] 1. A reaction mixture for preparing phosgene, the mixture comprising:

[0217] (i) A catalyst for preparing phosgene, the catalyst comprising a porous material comprising carbon, micropores, and mesopores, wherein the pore size of the micropores (preferably determined according to DIN 66135-2) is less than 2 nm, and the pore size of the mesopores (preferably determined according to DIN 66134) is in the range of 2-50 nm, wherein the volume of the mesopores of the porous material, preferably determined according to the double isotherm nonlocal density functional theory (NLDFT) advanced pore size distribution (PSD) technique, is at least 0.45 ml / g; and

[0218] (ii) A gas stream G containing carbon monoxide (CO) and chlorine (Cl2).

[0219] 2. The reaction mixture of Embodiment 1, wherein the ratio of the mesopore volume of the porous material of catalyst (i) to the micropore volume of the porous material of catalyst (i) is at least 1:1, preferably in the range of 1.1:1 to 6:1, more preferably in the range of 1.15:1 to 5:1, and even more preferably in the range of 1.2:1 to 4:1, preferably the mesopore volume and the micropore volume of the porous material are determined according to the dual isotherm NLDFT advanced PSD technology.

[0220] 3. The reaction mixture of embodiment 1 or 2, wherein the ratio of the mesopore volume of the porous material of catalyst (i) to the total pore volume of the porous material of catalyst (i) is at least 0.5:1, preferably in the range of 0.5:1 to 0.9:1, more preferably in the range of 0.55:1 to 0.85:1, more preferably in the range of 0.6:1 to 0.8:1, and even more preferably in the range of 0.65:1 to 0.8:1, preferably determined according to the dual isotherm NLDFT advanced PSD technology.

[0221] 4. The reaction mixture of any one of embodiments 1 to 3, wherein the mesopore volume of the porous material of catalyst (i) is at least 0.5 ml / g.

[0222] 5. The reaction mixture of any one of embodiments 1 to 4, wherein the total pore volume of the porous material of the catalyst (i) is in the range of 0.5-2.25 ml / g, preferably between 0.55-1.75 ml / g, more preferably between 0.65-1.70 ml / g, and the total pore volume of the porous material is preferably determined according to the dual isotherm NLDFT advanced PSD technology.

[0223] 6. The reaction mixture of any one of the embodiments 1 to 5, wherein less than or equal to 40%, more preferably less than or equal to 30%, more preferably less than or equal to 25%, more preferably less than or equal to 20%, more preferably less than or equal to 15%, more preferably less than or equal to 10%, more preferably less than or equal to 5%, more preferably less than or equal to 2.5%, more preferably less than or equal to 1% of the total pore volume of the porous material of the catalyst (i) is located in mesopores with a pore size greater than 20 nm.

[0224] 7. The reaction mixture of any one of embodiments 1 to 6, wherein the mesopore volume of the porous material of catalyst (i) is in the range of 0.50-0.54 ml / g, preferably in the range of 0.51-0.53 ml / g, and the ratio of the mesopore volume of the porous material of catalyst (i) to the total pore volume of the porous material of catalyst (i) is in the range of 0.70:1 to 0.75:1, preferably in the range of 0.72:1 to 0.74:1, wherein the mesopore volume and the total pore volume of the porous material are preferably determined according to the dual isotherm NLDFT advanced PSD technique.

[0225] 8. The reaction mixture of any one of embodiments 1 to 6, wherein the mesopore volume of the porous material of catalyst (i) is in the range of 0.64-0.70 ml / g, preferably in the range of 0.65-0.67 ml / g, and the ratio of the mesopore volume of the porous material of catalyst (i) to the total pore volume of the porous material of catalyst (i) is in the range of 0.72:1 to 0.78:1, preferably in the range of 0.73:1 to 0.76:1, preferably determined according to the dual isotherm NLDFT advanced PSD technique.

[0226] 9. The reaction mixture of any one of embodiments 1 to 8, wherein the volume of the micropores of the porous material of catalyst (i) (preferably determined according to the dual isotherm NLDFT advanced PSD technique) is at most 0.7 ml / g, preferably at most 0.6 ml / g.

[0227] 10. The reaction mixture of any one of embodiments 1 to 9, wherein the porous material of catalyst (i) has a BET specific surface area of ​​at least 500 m². 2 / g, preferably in the range of 500-2500 m 2 Within the range of / g, more preferably within the range of 550-1800 m 2 Within the range of / g, preferably in the range of 600-1500 m 2 Within the range of / g.

[0228] 11. The reaction mixture of any one of embodiments 1 to 10, wherein the total specific surface area of ​​the porous material of catalyst (i), as measured by dual isotherm NLDFT advanced PSD technology, is at least 600 m². 2 / g, preferably 650-2000 m 2 Within the range of / g, more preferably within 700-1800 m 2 Within the range of / g.

[0229] 12. The reaction mixture of any one of embodiments 1 to 11, wherein the specific surface area of ​​the porous material of catalyst (i) as measured by dual isothermal NLDFT advanced PSD technology is between 70 and 250 m². 2 Within the range of / g, preferably 80-170 m 2 Within the range of / g.

[0230] 13. The reaction mixture of Embodiment 12, wherein the ratio of the specific surface area of ​​the porous material of catalyst (i) caused by the mesopores to the total specific surface area of ​​the porous material of catalyst (i) is in the range of 0.07:1 to 0.40:1, more preferably in the range of 0.07:1 to 0.20:1.

[0231] 14. The reaction mixture of any one of embodiments 1 to 13, wherein the porous material of the catalyst (i) is pyrolytic carbon aerogel, preferably active pyrolytic carbon aerogel.

[0232] 15. The reaction mixture of any one of embodiments 1 to 14, wherein the porous material of the catalyst (i) is composed of carbon in 99% to 100% by weight, preferably 99.5% to 100% by weight, and more preferably 99.9% to 100% by weight.

[0233] 16. The reaction mixture of any one of embodiments 1 to 15, wherein the porous material of catalyst (i) consists of oxygen in a fraction of less than or equal to 0.5% by weight.

[0234] 17. The reaction mixture of any one of embodiments 1 to 16, wherein the porous material of catalyst (i) is composed of hydrogen in an amount of less than or equal to 0.5% by weight, more preferably equal to 0.1% by weight.

[0235] 18. The reaction mixture of any of the embodiments 1 to 17, wherein the porous material of catalyst (i) consists of nitrogen in a fraction of less than or equal to 0.01% by weight.

[0236] 19. The reaction mixture of any one of embodiments 1 to 18, wherein, based on total internal reflection X-ray fluorescence data, the ash content of the porous material of the catalyst (i) is less than or equal to 0.1 wt%, more preferably less than or equal to 0.08 wt%, more preferably less than or equal to 0.05 wt%, even more preferably less than or equal to 0.03 wt%, more preferably less than or equal to 0.025 wt%, more preferably less than or equal to 0.01 wt%, more preferably less than or equal to 0.0075 wt%, more preferably less than or equal to 0.005 wt%, and more preferably less than or equal to 0.001 wt%.

[0237] 20. The reaction mixture of any one of the embodiments 1 to 19, wherein the porous material of the catalyst (i) has a total impurity content of elements with atomic numbers of 11 to 92 as measured by total reflection X-ray fluorescence (TXRF) of less than 500 ppm, preferably less than 300 ppm, more preferably less than 200 ppm, and even more preferably less than 100 ppm.

[0238] 21. The reaction mixture of any one of embodiments 1 to 20, wherein 99-100% by weight, preferably 99.5-100% by weight, and more preferably 99.9-100% by weight, of the catalyst (i) is composed of a porous material.

[0239] 22. The reaction mixture of embodiment 21, wherein the catalyst (i) is a porous material.

[0240] 23. The reaction mixture of any one of embodiments 1 to 22, wherein the gas stream G consists of carbon monoxide and chlorine.

[0241] 24. A catalyst for preparing phosgene, comprising a porous material containing carbon, micropores, and mesopores, wherein the pore size of the micropores (preferably determined according to DIN 66135-2) is less than 2 nm, and the pore size of the mesopores (preferably determined according to DIN 66134) is in the range of 2-50 nm, wherein the mesopore volume of the porous material is in the range of 0.50-0.54 ml / g, and the ratio of the mesopore volume to the total pore volume of the porous material is in the range of 0.70:1 to 0.75:1, wherein the mesopore volume and the total pore volume of the porous material are preferably determined according to the dual isotherm NLDFT advanced PSD technique, wherein 99-100% by weight of the porous material is composed of carbon.

[0242] 25. The catalyst of embodiment 24, wherein the mesopore volume of the porous material is in the range of 0.51-0.53 ml / g, and the ratio of the mesopore volume of the porous material to the total pore volume of the porous material is in the range of 0.72:1 to 0.74:1.

[0243] 26. A catalyst for preparing phosgene, comprising a porous material containing carbon, micropores, and mesopores, wherein the pore size of the micropores (preferably determined according to DIN 66135-2) is less than 2 nm, and the pore size of the mesopores (preferably determined according to DIN 66134) is in the range of 2-50 nm, wherein the mesopore volume of the porous material is in the range of 0.64-0.70 ml / g, and the ratio of the mesopore volume to the total pore volume of the porous material is in the range of 0.72:1 to 0.78:1, preferably determined according to the dual isotherm NLDFT advanced PSD technique, wherein 99-100% by weight of the porous material is composed of carbon.

[0244] 27. The catalyst of embodiment 26, wherein the mesopore volume of the porous material is in the range of 0.65-0.67 ml / g, and the ratio of the mesopore volume of the porous material to the total pore volume of the porous material is in the range of 0.73:1 to 0.76:1.

[0245] 28. The catalyst of any one of embodiments 24 to 27, wherein the ratio of the mesopore volume of the porous material to the micropore volume of the porous material is at least 1:1, preferably in the range of 1.1:1 to 6:1, more preferably in the range of 1.15:1 to 5:1, and even more preferably in the range of 1.2:1 to 4:1, and preferably the mesopore volume and the micropore volume of the porous material are determined according to the dual isotherm NLDFT advanced PSD technology.

[0246] 29. The catalyst of any one of embodiments 24 to 28, wherein the total pore volume of the porous material is less than or equal to 40%, preferably less than or equal to 30%, more preferably less than or equal to 25%, more preferably less than or equal to 20%, more preferably less than or equal to 15%, more preferably less than or equal to 10%, more preferably less than or equal to 5%, more preferably less than or equal to 2.5%, and more preferably less than or equal to 1% in mesopores with a pore size greater than 20 nm.

[0247] 30. The catalyst of any of embodiments 24 to 29, wherein the micropore volume of the porous material is at most 0.7 ml / g, preferably at most 0.6 ml / g, and preferably determined according to the dual isotherm NLDFT advanced PSD technique.

[0248] 31. The catalyst of any one of embodiments 24 to 30, wherein the BET specific surface area of ​​the porous material is at least 500 m². 2 / g, preferably in the range of 500-2500 m 2 Within the range of / g, more preferably in the range of 550-1800 m 2 Within the range of / g, more preferably within the range of 600-1500 m 2 Within the range of / g.

[0249] 32. The catalyst of any one of embodiments 24 to 31, wherein the total specific surface area of ​​the porous material, as measured by dual isotherm NLDFT advanced PSD technology, is at least 600 m². 2 / g, preferably 650-2000 m 2 Within the range of / g, more preferably within 700-1800 m 2 Within the range of / g.

[0250] 33. The catalyst of any one of embodiments 24 to 32, wherein the specific surface area caused by the mesopores of the porous material, as measured by dual isothermal NLDFT advanced PSD technology, is 70-250 m². 2 Within the range of / g, preferably 80-170 m 2 Within the range of / g.

[0251] 34. The catalyst of embodiment 33, wherein the ratio of the specific surface area of ​​the porous material caused by the mesopores to the total specific surface area of ​​the porous material is in the range of 0.07:1 to 0.40:1, preferably in the range of 0.07:1 to 0.20:1.

[0252] 35. The catalyst of any of embodiments 24 to 34, wherein the porous material is pyrolytic carbon aerogel, preferably active pyrolytic carbon aerogel.

[0253] 36. The catalyst of any of embodiments 24 to 35, wherein 99.5-100% by weight, preferably 99.9-100% by weight, of the porous material is composed of carbon.

[0254] 37. The catalyst of any of embodiments 24 to 36, wherein less than or equal to 0.5% by weight of the porous material is composed of oxygen.

[0255] 38. The catalyst of any of embodiments 24 to 37, wherein less than or equal to 0.5% by weight, preferably less than or equal to 0.1% by weight, of the porous material is composed of hydrogen.

[0256] 39. The catalyst of any of embodiments 24 to 38, wherein less than or equal to 0.01% by weight of the porous material is composed of nitrogen.

[0257] 40. The catalyst of any one of embodiments 24 to 39, wherein, based on total internal reflection X-ray fluorescence data, the ash content of the porous material, calculated by weight, is less than or equal to 0.1 wt%, preferably less than or equal to 0.08 wt%, more preferably less than or equal to 0.05 wt%, even more preferably less than or equal to 0.03 wt%, more preferably less than or equal to 0.025 wt%, more preferably less than or equal to 0.01 wt%, more preferably less than or equal to 0.0075 wt%, more preferably less than or equal to 0.005 wt%, and more preferably less than or equal to 0.001 wt%.

[0258] 41. The catalyst of any one of embodiments 24 to 40, wherein the porous material has a total impurity content of elements with atomic numbers between 11 and 92 as measured by total reflection X-ray fluorescence (TXRF) of less than or equal to 500 ppm, preferably less than or equal to 300 ppm, more preferably less than or equal to 200 ppm, and even more preferably less than or equal to 100 ppm.

[0259] 42. The catalyst of any one of embodiments 24 to 41, wherein 99-100% by weight, preferably 99.5-100% by weight, and more preferably 99.9-100% by weight, of the catalyst is composed of porous material.

[0260] 43. The catalyst of embodiment 42 is a porous material.

[0261] 44. Use of the catalyst according to any one of embodiments 24 to 43 or the reaction mixture according to any one of embodiments 1 to 23 for the preparation of phosgene.

[0262] 45. A method for preparing a catalyst, wherein the catalyst is catalyst (i) in a reaction mixture for preparing phosgene according to any one of embodiments 1 to 23, or catalyst according to any one of embodiments 24 to 43, the method comprising:

[0263] a) Prepare a mixture comprising a solvent, a catalyst, a first monomer, and a second monomer;

[0264] b) Copolymerize the first and second monomers of the mixture obtained in a) to obtain a resin mixture;

[0265] c) Heating the resin mixture obtained according to b) at the curing temperature to obtain a polymer composition comprising a solvent and a polymer formed by copolymerizing a first monomer and a second monomer, wherein the solvent concentration in the polymer composition is at least 40% by weight based on the total weight of the polymer composition; and

[0266] d) Pyrolyze the polymer composition obtained according to c) at the pyrolysis temperature, thereby substantially removing the solvent and pyrolyzing the polymer to obtain the catalyst.

[0267] 46. ​​A method for preparing a catalyst (i), wherein the catalyst is the catalyst (i) in a reaction mixture for preparing phosgene according to any one of embodiments 1 to 23, or the catalyst according to any one of embodiments 24 to 43, the method comprising:

[0268] 1) Prepare a mixture comprising a solvent, a catalyst, a first monomer, and a second monomer, and maintain the reaction mixture at the reaction temperature for the specified reaction time;

[0269] 2) Copolymerize the first and second monomers of the mixture obtained in 1) to obtain a resin mixture;

[0270] 3) Curing the resin mixture obtained according to 2) at a curing temperature to obtain a polymer composition comprising a solvent and a polymer formed by copolymerizing the first monomer and the second monomer according to 2);

[0271] 4) Pyrolyze the polymer composition obtained according to 3) at a pyrolysis temperature, thereby substantially removing the solvent and pyrolyzing the polymer to obtain a carbon material; and

[0272] 5) Optionally, the carbon material is activated at the activation temperature to increase the surface area and pore volume to the desired level, thereby obtaining a catalyst.

[0273] 47. The method of embodiment 45 or 46, wherein the first monomer is resorcinol and the second monomer is formaldehyde.

[0274] 48. The method of any of the embodiments 45 to 47, wherein the solvent comprises water and acetic acid, preferably water and acetic acid.

[0275] 49. The method of any one of embodiments 45 to 48, wherein the catalyst is an ammonium acetate catalyst.

[0276] In the context of this invention, the total pore volume of a porous material is the sum of the mesopore volume and the micropore volume of the porous material.

[0277] In the context of this invention, the total specific surface area of ​​the porous material is preferably determined by dual isothermal NLDFT advanced pore size distribution (Micro-meretics ASAP 2020_Micromeritics Instrument Corp., Norcross, GA, USA). NLDFT surface area is expressed in m². 2 / g represents the amount of gas adsorbed on a material. The NLDFT advanced pore size distribution technique uses a maximum of two inert gases, namely nitrogen and carbon dioxide, to measure the amount of gas adsorbed on the material and can be used to determine the accessible surface area of ​​a given material.

[0278] Furthermore, in the context of this invention, the total pore volume of a porous material is preferably determined by dual isotherm NLDFT advanced pore size distribution (Micro-meretics ASAP 2020_Micromeretics Instrument Corp., Norcross, GA, USA). The total pore volume is expressed in ml / g. The NLDFT advanced pore size distribution technique uses up to two inert gases, namely nitrogen and carbon dioxide, to measure the amount of gas adsorbed on a given material and can be used to determine the total pore volume of said given material. Similarly, the pore volume (mesopores, micropores) within certain pore size ranges is also determined using the same method. Therefore, the mesopore volume and micropore volume of a porous material are determined by dual isotherm NLDFT advanced pore size distribution (Micromeretics ASAP 2020).

[0279] In this invention, "TXRF impurity" or "TXRF element" can be any impurity element with an atomic number between 11 and 92 (i.e., from beryllium to uranium). The terms "total TXRF impurity content" and "total TXFR impurity level" both refer to the sum of all TXFR impurities present in a sample (e.g., a porous material). TXRF impurity concentration and identification can be determined by total reflectance X-ray fluorescence (TXRF).

[0280] The oxygen, hydrogen, and nitrogen content of porous materials can be determined through combustion analysis. Techniques for determining elemental composition through combustion analysis are well-known in the field.

[0281] Furthermore, in the context of this invention, "pore" refers to an opening or recess on a surface, or a channel in a given porous material (e.g., pyrolytic carbon material). A pore can be a single channel or connected to other channels in a continuous network throughout the porous material structure.

[0282] In the context of this invention, the term "BET specific surface area" refers to the total specific surface area of ​​a material (e.g., a porous material) that can be measured using BET technology. BET specific surface area is expressed in m³. 2 / g represents the area. For example, the BET specific surface area can be determined by the BET (Brunauer / Emmett / Teller) method, which is performed by physical adsorption of nitrogen at -196°C (liquid nitrogen) using a Micrometrics ASAP 2420 instrument.

[0283] Examples 1 and 2 further illustrate the present invention.

[0284] Example

[0285] Reference example: Method for preparing a catalyst for preparing phosgene according to the present invention

[0286] The catalysts (porous carbon materials) 4 to 7 according to the invention are prepared by the method defined in WO 2012 / 092210 A1: one method for producing such high surface area activated carbon materials is to prepare synthetic polymers from carbon-containing organic components (e.g., polymer gels). For example, different catalysts can be obtained by changing the polymerization and gelation conditions (temperature, duration, etc.). Using existing organic materials, the synthetically prepared polymers are dried (e.g., by evaporation or freeze-drying), pyrolyzed, and activated to generate activated carbon materials (e.g., aerogels or dry gels). Therefore, the method for preparing catalysts 4 to 7, i.e., a porous material (pyrolytic carbon aerogel) comprising carbon, micropores, and mesopores, includes:

[0287] A mixture comprising a solvent (water / acetic acid), a catalyst (ammonium acetate catalyst), a first monomer (resorcinol), and a second monomer (formaldehyde) is prepared.

[0288] The first and second monomers of the mixture are copolymerized to obtain a resin mixture;

[0289] The resin mixture obtained by curing at a curing temperature (e.g., 95°C) yields a polymer composition comprising a solvent and a polymer formed by copolymerizing a first monomer and a second monomer, wherein the solvent concentration in the polymer composition is at least 40% by weight based on the total weight of the polymer composition; and

[0290] The obtained polymer composition is pyrolyzed at a pyrolysis temperature, thereby substantially removing the solvent and pyrolyzing the polymer to produce a carbon material. Alternatively, the method includes:

[0291] A mixture comprising a solvent (water / acetic acid), a catalyst (ammonium acetate catalyst), a first monomer (resorcinol), and a second monomer (formaldehyde) is prepared, and the reaction mixture is maintained at the reaction temperature for a certain period of time.

[0292] The first and second monomers of the obtained mixture are copolymerized to obtain a resin mixture;

[0293] The resin mixture obtained by curing at a curing temperature (e.g., 95°C) yields a polymer composition comprising a solvent and a polymer formed by copolymerizing a first monomer and a second monomer.

[0294] The polymer composition obtained by pyrolysis at a pyrolysis temperature, thereby substantially removing the solvent and pyrolyzing the polymer, yields a carbon material; and

[0295] Optionally, the carbon material is activated at an activation temperature to increase the surface area and pore volume to the desired level, thereby generating porous carbon material 4 to 7. Curing is carried out at a high temperature, for example, around 95°C.

[0296] Example: A method for preparing phosgene using the catalyst of the present invention (samples 4-8) and prior art catalysts (samples 1 and 3).

[0297] General steps:

[0298] The extrusion or granules of the fresh catalyst under test were ground and sieved to obtain particles in the range of 1.5–2 mm. 0.2 g of the particles were packed into a 5.4 mm inner diameter reaction tube placed within a heating mantle. A mixture of 15.9 Nl / h CO and 14.6 Nl / h Cl2 was fed into the reaction tube, maintained at 400°C. These conditions were maintained for 15 hours to allow for catalyst conditioning (e.g., chlorination). Subsequently, the temperature was lowered to 250°C, the CO / Cl2 mixture was reduced to 1 / 10, and N2 was added to the reaction tube to obtain the original molar flow rate. The phosgene (CDC) concentration at the outlet was measured by infrared spectroscopy.

[0299] The pore size distribution of the fresh catalyst below 100 nm was measured using dual isothermal NLDFT advanced PSD.

[0300] The results are summarized in Table 1 below. The specific surface area (SSA) listed in Table 1 is expressed in m². 2 / g indicates the quantity. Furthermore, it is noteworthy that catalyst 7 (sample 7) was activated after pyrolysis.

[0301] Table 1

[0302]

Claims

1. A method for producing phosgene, comprising a gas-phase reaction of carbon monoxide and chlorine in the presence of a carbon catalyst in a multi-tube reactor, wherein the carbon catalyst comprises a certain amount of mesopores with a pore size in the range of 2-50 nm, the total pore volume of the mesopores being at least 0.45 ml / g, wherein 50% to 80% of the total pore volume of the carbon catalyst is located in the mesopores, and 20% to 50% of the total pore volume is located in the micropores, the micropores having a pore size of less than 2 nm.

2. The method according to claim 1, wherein, The total pore volume of the carbon catalyst, as determined by nitrogen adsorption, ranged from 0.60 ml / g to 2 ml / g.

3. The method according to any one of claims 1 to 2, wherein the BET surface area of ​​the carbon catalyst is at least 500 m². 2 / g.

4. The method according to any one of claims 1 to 2, wherein the BET surface area of ​​the carbon catalyst is 500 m². 2 / g to 2500 m 2 Within the range of / g.

5. The method according to any one of claims 1 to 2, wherein the carbon catalyst is a pyrolytic carbon aerogel.

6. The method according to claim 5, wherein the carbon catalyst is an activated pyrolytic carbon aerogel.

7. The method according to any one of claims 1 to 2, wherein the carbon catalyst has a total impurity content of elements with atomic numbers between 11 and 92 of less than 500 ppm, the total impurity content being measured by total reflectance X-ray fluorescence.

8. The method according to any one of claims 1 to 2, wherein the reaction occurs in a tube bundle reactor in which the tubes are filled with catalyst.

9. The method according to claim 8, wherein the cooling medium on the shell side is a liquid.

10. The method according to claim 8, wherein the cooling medium on the shell side is a boiling liquid.

11. The method according to any one of claims 1 to 2, wherein the stoichiometric excess of carbon monoxide in the feed stream relative to chlorine is 0.001-50 mol.

12. The method according to any one of claims 1 to 2, wherein the reaction occurs at a pressure of 1-10 bara.

13. The method according to any one of claims 1 to 2, wherein the feed flow is provided with an absolute pressure in the range of 0.5-20 bara.

14. The method according to any one of claims 1 to 2, wherein the reaction is carried out at 0.5-6 kg phosgene / m³ 2 The surface load is applied.

15. The method according to any one of claims 1 to 2, wherein at least one fluid heat carrier passes through a contact pipe in a separate cooling zone.

16. The method of claim 15, wherein a liquid heat carrier is used as the fluid heat carrier.

17. The method according to any one of claims 1 to 2, wherein steam is generated directly or indirectly.

18. Uses of carbon catalysts in the production of phosgene, among which, The carbon catalyst contains a certain amount of mesopores, the pore size of which is in the range of 2-50 nm, and the total pore volume of the mesopores is at least 0.45 ml / g. 50% to 80% of the total pore volume of the carbon catalyst is located in the mesopores, and 20% to 50% of the total pore volume is located in the micropores, the pore size of which is less than 2 nm.

19. A reaction mixture for preparing phosgene, the mixture comprising: (i) A catalyst for preparing phosgene, the catalyst comprising a porous material containing carbon and having micropores and mesopores, wherein the micropores have a pore size less than 2 nm, the mesopores have a pore size ranging from 2 to 50 nm, wherein the mesopore volume of the porous material is at least 0.45 ml / g, and wherein 50% to 80% of the total pore volume of the porous material is located in the mesopores, and 20% to 50% of the total pore volume is located in the micropores, the micropores having a pore size less than 2 nm; and (ii) A gas stream G containing carbon monoxide (CO) and chlorine (Cl2).

20. The reaction mixture according to claim 19, wherein the ratio of the mesopore volume of the porous material of catalyst (i) to the micropore volume of the porous material of catalyst (i) is in the range of 1.1:1 to 4:

1.

21. The reaction mixture according to claim 19, wherein the ratio of the mesopore volume of the porous material of catalyst (i) to the micropore volume of the porous material of catalyst (i) is in the range of 1.15:1 to 4:

1.

22. The reaction mixture according to claim 19, wherein the ratio of the mesopore volume of the porous material of catalyst (i) to the micropore volume of the porous material of catalyst (i) is in the range of 1.2:1 to 4:

1.

23. The reaction mixture according to claim 19, wherein the total pore volume of the porous material of catalyst (i) is in the range of 0.60-2.25 ml / g.

24. The reaction mixture according to claim 23, wherein the total pore volume of the porous material of catalyst (i) is in the range of 0.60-1.75 ml / g.

25. The reaction mixture according to claim 23, wherein the total pore volume of the porous material of catalyst (i) is in the range of 0.65-1.70 ml / g.

26. The reaction mixture according to any one of claims 19 to 20, wherein, Less than or equal to 40% of the total pore volume of the porous material of catalyst (i) exists in mesopores with a pore size greater than 20 nm.

27. The reaction mixture according to claim 26, wherein, Less than or equal to 30% of the total pore volume of the porous material of catalyst (i) exists in mesopores with a pore size greater than 20 nm.

28. The reaction mixture according to claim 26, wherein, Less than or equal to 25% of the total pore volume of the porous material of catalyst (i) exists in mesopores with a pore size greater than 20 nm.

29. The reaction mixture according to claim 26, wherein, Less than or equal to 20% of the total pore volume of the porous material of catalyst (i) exists in mesopores with a pore size greater than 20 nm.

30. The reaction mixture according to claim 26, wherein, Less than or equal to 15% of the total pore volume of the porous material of catalyst (i) exists in mesopores with a pore size greater than 20 nm.

31. The reaction mixture according to claim 26, wherein, Less than or equal to 10% of the total pore volume of the porous material of catalyst (i) exists in mesopores with a pore size greater than 20 nm.

32. The reaction mixture according to claim 26, wherein, The total pore volume of the porous material of catalyst (i) is less than or equal to 5% in the mesopores with a pore size greater than 20 nm.

33. The reaction mixture according to claim 26, wherein, Less than or equal to 2.5% of the total pore volume of the porous material of catalyst (i) exists in mesopores with a pore size greater than 20 nm.

34. The reaction mixture according to claim 26, wherein, The total pore volume of the porous material of catalyst (i) is less than or equal to 1% in the mesopores with a pore size greater than 20 nm.

35. The reaction mixture according to any one of claims 19 to 21, wherein the mesopore volume of the porous material of catalyst (i) is in the range of 0.50-0.54 ml / g, and the ratio of the mesopore volume of the porous material of catalyst (i) to the total pore volume of the porous material of catalyst (i) is in the range of 0.70:1 to 0.75:

1.

36. The reaction mixture according to claim 35, wherein the mesopore volume of the porous material of catalyst (i) is in the range of 0.51-0.53 ml / g.

37. The reaction mixture according to claim 35, wherein, The ratio of the mesopore volume of the porous material of catalyst (i) to the total pore volume of the porous material of catalyst (i) is in the range of 0.72:1 to 0.74:

1.

38. The reaction mixture according to any one of claims 19 to 22, wherein the micropore volume of the porous material of catalyst (i) is at most 0.7 ml / g.

39. The reaction mixture according to claim 38, wherein the micropore volume of the porous material of catalyst (i) is at most 0.6 ml / g.

40. The reaction mixture according to any one of claims 19 to 23, wherein the specific surface area of ​​the porous material of the catalyst (i) caused by mesopores is 70-250 m². 2 Within the range of / g.

41. The reaction mixture according to claim 40, wherein the specific surface area of ​​the porous material of the catalyst (i) caused by mesopores is in the range of 80-170 m². 2 Within the range of / g.

42. The reaction mixture according to any one of claims 19 to 24, wherein the porous material of the catalyst (i) is pyrolytic carbon aerogel.

43. The reaction mixture according to claim 42, wherein the porous material of the catalyst (i) is an active pyrolytic carbon aerogel.

44. The reaction mixture according to any one of claims 19 to 25, wherein 99-100% by weight of the porous material of the catalyst (i) is composed of carbon.

45. The reaction mixture according to claim 44, wherein 99.5-100% by weight of the porous material of the catalyst (i) is composed of carbon.

46. ​​The reaction mixture according to claim 44, wherein 99.9-100% by weight of the porous material of the catalyst (i) is composed of carbon.

47. The reaction mixture according to any one of claims 19 to 25, wherein the porous material of the catalyst (i) has a total impurity content of elements with atomic numbers from 11 to 92 of less than 500 ppm, said total impurity content being measured by total reflectance X-ray fluorescence.

48. The reaction mixture according to claim 47, wherein the porous material of catalyst (i) has a total impurity content of elements with atomic numbers from 11 to 92 of less than 300 ppm, said total impurity content being measured by total reflectance X-ray fluorescence.

49. The reaction mixture according to claim 47, wherein the porous material of catalyst (i) has a total impurity content of elements with atomic numbers from 11 to 92 of less than 200 ppm, said total impurity content being measured by total reflectance X-ray fluorescence.

50. The reaction mixture according to claim 47, wherein the porous material of catalyst (i) has a total impurity content of elements with atomic numbers from 11 to 92 of less than 100 ppm, said total impurity content being measured by total reflectance X-ray fluorescence.

51. A catalyst for preparing phosgene, comprising a porous material containing carbon, and the porous material having micropores and mesopores, wherein the micropores have a pore size less than 2 nm, and the mesopores have a pore size ranging from 2 to 50 nm, wherein... The mesopore volume of the porous material is in the range of 0.50-0.54 ml / g, wherein the volume fraction of the mesopores is at least 50% of the total pore volume, the ratio of the mesopore volume to the total pore volume of the porous material is in the range of 0.70:1 to 0.75:1, 20% to 50% of the total pore volume is located in micropores, and 99-100% by weight of the porous material is composed of carbon.

52. The catalyst according to claim 51, wherein the mesopore volume of the porous material is in the range of 0.51-0.53 ml / g, and the ratio of the mesopore volume of the porous material to the total pore volume of the porous material is in the range of 0.72:1 to 0.74:

1.

53. A catalyst for preparing phosgene, comprising a porous material containing carbon, and the porous material having micropores and mesopores, wherein the micropores have a pore size of less than 2 nm, the mesopores have a pore size between 2 and 50 nm, wherein the mesopore volume of the porous material is between 0.64 and 0.70 ml / g, wherein the mesopore volume fraction is at least 50% of the total pore volume, the ratio of the mesopore volume to the total pore volume of the porous material is between 0.72:1 and 0.78:1, 20% to 50% of the total pore volume is located in the micropores, and wherein 99-100% by weight of the porous material is composed of carbon.

54. The catalyst according to claim 53, wherein the mesopore volume of the porous material is in the range of 0.65-0.67 ml / g, and the ratio of the mesopore volume of the porous material to the total pore volume of the porous material is in the range of 0.73:1 to 0.76:

1.

55. The catalyst according to any one of claims 51 to 54, wherein the total specific surface area of ​​the porous material, as measured by dual isotherm NLDFT advanced PSD technology, is at least 600 m². 2 / g.

56. The catalyst according to claim 55, wherein the total specific surface area of ​​the porous material, as measured by dual isotherm NLDFT advanced PSD technology, is in the range of 650-2000 m². 2 Within the range of / g.

57. The catalyst according to claim 55, wherein the total specific surface area of ​​the porous material, as measured by dual isotherm NLDFT advanced PSD technology, is in the range of 700-1800 m². 2 Within the range of / g.

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