A catalyst carrier, a method of preparation, and a catalyst for the production of chlorine and a method of preparation of the catalyst

Abstract

This invention discloses a catalyst support, a preparation method, and a catalyst for preparing chlorine gas. The catalyst preparation materials include a catalyst support and an aqueous solution of ruthenium trichloride. The catalyst support is rutile titanium dioxide containing oxygen vacancies, which is prepared by subjecting anatase titanium dioxide to high-temperature ultraviolet treatment in an inert atmosphere. The preparation method for the catalyst involves impregnating the ruthenium trichloride aqueous solution onto the oxygen-vacancy-containing rutile titanium dioxide using an equal-volume impregnation method, drying at 80–120°C for 6–24 hours, and then heating at 250–350°C in an oxygen or air atmosphere for 6–16 hours. This catalyst overcomes the shortcomings of existing technologies, exhibiting a high reaction rate at a relatively low reaction temperature (300°C), and achieving a hydrogen chloride conversion rate close to the hydrogen chloride equilibrium conversion rate.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a catalyst support for the preparation of chlorine gas, a catalyst composed thereof, and a method for preparing the catalyst. Background Technology

[0002] Chlorine is widely used as a reaction intermediate in the manufacture of industrial and consumer products, particularly polyurethane and polycarbonate. However, approximately 50% of global chlorine production ultimately results in hydrogen chloride or chloride salts as byproducts. This is especially true in the production of toluene diisocyanate (TDI), where every mole of TDI produced generates 4 moles of HCl as a byproduct. Although the byproduct hydrogen chloride can be used to make hydrochloric acid for sale, market demand is limited. With the large-scale development of the chlor-alkali industry, global chlorine production has increased year by year, from 65 million tons in 2010 to over 88 million tons in 2020, resulting in a far greater demand for hydrogen chloride than market needs.

[0003] Converting hydrogen chloride into chlorine gas enables closed-loop recycling of chlorine resources and is the most effective method for treating recovered byproduct hydrogen chloride, a concept widely accepted in the chlorine industry. Currently, the main methods for converting hydrogen chloride into chlorine gas include direct oxidation, electrolysis, and catalytic oxidation (the Deacon reaction process). Among these, catalytic oxidation, using oxygen as the oxidant, offers advantages such as low energy consumption and no side reactions, making it the best approach for sustainable development in the chlorine industry. The catalytic oxidation of hydrogen chloride is exothermic; to increase the reaction rate, higher reaction temperatures are required when using low-activity catalysts, which significantly reduces the equilibrium conversion rate of hydrogen chloride. Therefore, developing low-temperature, high-activity catalysts is crucial for achieving the production of chlorine from hydrogen chloride. Since copper-based catalysts (Deacon catalysts), iron-based, chromium-based, ruthenium-based, and cerium-based metal catalysts have been introduced (ACSCatalysis, 2013, 3, 1034). Among these, ruthenium-based catalysts, with ruthenium dioxide supported on rutile titanium dioxide, exhibit the highest activity, but their low-temperature (<320℃) reaction rate still needs improvement. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a catalyst support, a preparation method, a catalyst for preparing chlorine, and a method for preparing the catalyst. This catalyst overcomes the above-mentioned shortcomings in the prior art, exhibits a high reaction rate at a relatively low reaction temperature (300°C), and can achieve a hydrogen chloride conversion rate close to the hydrogen chloride equilibrium conversion rate.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is a catalyst support, wherein the catalyst support is rutile titanium dioxide containing oxygen vacancies.

[0006] A method for preparing a catalyst support involves subjecting anatase titanium dioxide to high-temperature ultraviolet treatment in an inert atmosphere, resulting in a rutile titanium dioxide catalyst support containing oxygen vacancies.

[0007] In one embodiment of the present invention, the inert atmosphere is any one of nitrogen, helium and argon.

[0008] In one embodiment of the present invention, the high-temperature ultraviolet treatment time is 0.5 to 6 hours, and the high temperature is 600 to 1000°C.

[0009] In one embodiment of the present invention, the ultraviolet treatment is performed by irradiation with an ultraviolet lamp.

[0010] A catalyst for preparing chlorine gas, wherein the raw materials for preparing the catalyst include the catalyst support and an aqueous solution of ruthenium trichloride.

[0011] A method for preparing a catalyst for chlorine production involves impregnating ruthenium trichloride aqueous solution onto rutile titanium dioxide containing oxygen vacancies using an equal-volume impregnation method, drying at 80–120°C for 6–24 hours, and then heating at 250–350°C in an oxygen or air atmosphere for 6–16 hours.

[0012] In one embodiment of the present invention, the concentration of the ruthenium trichloride aqueous solution is 0.05 g / mL.

[0013] In one embodiment of the present invention, the rutile titanium dioxide containing oxygen vacancies is obtained by subjecting anatase titanium dioxide to high-temperature ultraviolet treatment in an inert atmosphere.

[0014] The catalyst is used to catalyze the production of chlorine from hydrogen chloride and oxygen. The catalyst is packed into a fixed-bed reactor at atmospheric pressure, heated to 300°C under a nitrogen atmosphere, and purged at this temperature for a certain period of time. Then, the nitrogen is turned off, and hydrogen chloride and oxygen are introduced into the catalyst bed at rates of 200 mL / min and 50 mL / min, respectively, to react.

[0015] The beneficial effects of this invention are:

[0016] This invention uses rutile titanium dioxide containing oxygen vacancies as a catalyst support, which can highly disperse the active component of ruthenium dioxide. The resulting catalyst is particularly suitable for catalyzing the reaction of hydrogen chloride and oxygen to produce chlorine. It has a high reaction rate at a relatively low reaction temperature (300°C) and can achieve a hydrogen chloride conversion rate close to the hydrogen chloride equilibrium conversion rate. Attached Figure Description

[0017] Figure 1 This is the electron paramagnetic resonance image of Embodiment 1 of the present invention;

[0018] Figure 2This is a transmission electron microscope image of Embodiment 1 of the present invention;

[0019] Figure 3 This is the electron paramagnetic resonance image of Comparative Example 1 of this invention;

[0020] Figure 4 This is a transmission electron microscope image of Comparative Example 1 of the present invention. Detailed Implementation

[0021] The following is a description of the embodiments and appendices. Figures 1 to 4 The present invention will be further described below. Except as specifically mentioned below, the processes, conditions, and experimental methods for implementing the present invention are all common knowledge and general knowledge in the art, and the present invention does not have any particular limitations. All embodiments are operated according to the above-described technical solution steps.

[0022] Example 1

[0023] (1) Anatase titanium dioxide was placed in a nitrogen atmosphere and irradiated with an ultraviolet lamp at 600°C for 6 hours to obtain rutile titanium dioxide containing oxygen vacancies.

[0024] (2) The ruthenium trichloride aqueous solution with a concentration of 0.05 g / mL was impregnated onto the rutile titanium dioxide containing oxygen vacancies obtained in step (1) by the equal volume impregnation method. After drying at 100°C for 12 hours, it was heated at 250°C in an oxygen atmosphere for 10 hours.

[0025] Electron paramagnetic resonance imaging (EPR) Figure 1 The results showed that a peak was observed at g = 2.005, indicating that the rutile titanium dioxide contained oxygen vacancies.

[0026] Transmission electron microscope image ( Figure 2 The results showed that the ruthenium dioxide on the catalyst was 2 nm in size and exhibited a highly dispersed state.

[0027] Example 2

[0028] (1) Anatase titanium dioxide was placed in a nitrogen atmosphere and treated with ultraviolet light at 1000℃ for 0.5 hours to obtain rutile titanium dioxide containing oxygen vacancies.

[0029] (2) The ruthenium trichloride aqueous solution with a concentration of 0.05 g / mL was impregnated onto the rutile titanium dioxide containing oxygen vacancies obtained in step (1) by the equal volume impregnation method. After drying at 80°C for 24 hours, it was heated at 350°C in air atmosphere for 6 hours.

[0030] The electron paramagnetic resonance (EPR) results showed a peak at g = 2.005, indicating that the rutile titanium dioxide contained oxygen vacancies.

[0031] Transmission electron microscopy results show that the ruthenium dioxide on the catalyst is 2 nm in size and exhibits a highly dispersed state.

[0032] Example 3

[0033] (1) Anatase titanium dioxide was placed in a nitrogen atmosphere and treated with ultraviolet light at 800°C for 3 hours to obtain rutile titanium dioxide containing oxygen vacancies.

[0034] (2) The ruthenium trichloride aqueous solution with a concentration of 0.05 g / mL was impregnated onto the rutile titanium dioxide containing oxygen vacancies obtained in step (1) by the equal volume impregnation method. After drying at 120°C for 6 hours, it was heated at 300°C in air atmosphere for 16 hours.

[0035] The electron paramagnetic resonance (EPR) results showed a peak at g = 2.005, indicating that the rutile titanium dioxide contained oxygen vacancies.

[0036] Transmission electron microscopy results show that the ruthenium dioxide on the catalyst is 2 nm in size and exhibits a highly dispersed state.

[0037] Example 4

[0038] (1) Anatase titanium dioxide was placed in a helium atmosphere and treated with ultraviolet light at 750°C for 4 hours to obtain rutile titanium dioxide containing oxygen vacancies.

[0039] (2) The ruthenium trichloride aqueous solution with a concentration of 0.05 g / mL was impregnated onto the rutile titanium dioxide containing oxygen vacancies obtained in step (1) by the equal volume impregnation method. After drying at 120°C for 12 hours, it was heated at 250°C in an oxygen atmosphere for 16 hours.

[0040] The electron paramagnetic resonance (EPR) results showed a peak at g = 2.005, indicating that the rutile titanium dioxide contained oxygen vacancies.

[0041] Transmission electron microscopy results show that the ruthenium dioxide on the catalyst is 2 nm in size and exhibits a highly dispersed state.

[0042] Example 5

[0043] (1) Anatase titanium dioxide was placed in an argon atmosphere and treated with ultraviolet light at 850°C for 6 hours to obtain rutile titanium dioxide containing oxygen vacancies.

[0044] (2) The ruthenium trichloride aqueous solution with a concentration of 0.05 g / mL was impregnated onto the rutile titanium dioxide containing oxygen vacancies obtained in step (1) by the equal volume impregnation method. After drying at 80°C for 24 hours, it was heated at 300°C in an oxygen atmosphere for 12 hours.

[0045] The electron paramagnetic resonance (EPR) results showed a peak at g = 2.005, indicating that the rutile titanium dioxide contained oxygen vacancies.

[0046] Transmission electron microscopy results show that the ruthenium dioxide on the catalyst is 2 nm in size and exhibits a highly dispersed state.

[0047] Comparative Example 1

[0048] (1) Anatase titanium dioxide was placed in a nitrogen atmosphere and treated at 600°C for 6 hours to obtain rutile titanium dioxide without oxygen vacancies.

[0049] (2) The ruthenium trichloride aqueous solution with a concentration of 0.05 g / mL was impregnated onto the rutile titanium dioxide obtained in step (1) without oxygen vacancies by the equal volume impregnation method. After drying at 100°C for 12 hours, it was heated at 250°C in an oxygen atmosphere for 10 hours.

[0050] Electron paramagnetic resonance imaging (EPR) Figure 3 The results showed no peak at g=2.005, indicating that the rutile titanium dioxide does not contain oxygen vacancies.

[0051] Transmission electron microscope image ( Figure 4 The results showed that the ruthenium dioxide on the catalyst was 5 nm in size and exhibited an aggregated state.

[0052] Comparative Example 2

[0053] (1) Anatase titanium dioxide was placed in an oxygen atmosphere and treated with ultraviolet light at 600°C for 6 hours to obtain rutile titanium dioxide without oxygen vacancies.

[0054] (2) The ruthenium trichloride aqueous solution with a concentration of 0.05 g / mL was impregnated onto the rutile titanium dioxide obtained in step (1) without oxygen vacancies by the equal volume impregnation method. After drying at 100°C for 12 hours, it was heated at 250°C in an oxygen atmosphere for 10 hours.

[0055] The electron paramagnetic resonance (EPR) results showed no peak at g = 2.005, indicating that the rutile titanium dioxide does not contain oxygen vacancies.

[0056] Transmission electron microscopy results show that the ruthenium dioxide on the catalyst is 5 nm in size and exhibits an aggregated state.

[0057] Comparative Example 3

[0058] (1) Anatase titanium dioxide was placed in an air atmosphere and treated with ultraviolet light at 600°C for 6 hours to obtain rutile titanium dioxide without oxygen vacancies.

[0059] (2) The ruthenium trichloride aqueous solution with a concentration of 0.05 g / mL was impregnated onto the rutile titanium dioxide obtained in step (1) without oxygen vacancies by the equal volume impregnation method. After drying at 100°C for 12 hours, it was heated at 250°C in an oxygen atmosphere for 10 hours.

[0060] The electron paramagnetic resonance (EPR) results showed no peak at g = 2.005, indicating that the rutile titanium dioxide does not contain oxygen vacancies.

[0061] Transmission electron microscopy results show that the ruthenium dioxide on the catalyst is 5 nm in size and exhibits an aggregated state.

[0062] Comparative Example 4

[0063] Ruthenium trichloride aqueous solution with a concentration of 0.05 g / mL was impregnated onto anatase titanium dioxide using the equal volume impregnation method. After drying at 100 °C for 12 hours, it was then heated at 250 °C in an oxygen atmosphere for 10 hours.

[0064] Electron paramagnetic resonance (EPR) results showed no peak at g = 2.005, indicating that this anatase titanium dioxide does not contain oxygen vacancies.

[0065] Transmission electron microscopy results show that the ruthenium dioxide on the catalyst is 10 nm in size and exhibits an aggregated state.

[0066] All examples and comparative examples were applied to the production of chlorine gas by hydroxyl chloride.

[0067] The reaction of hydrogen chloride to chlorine by hydrogen hydration: 0.5 g of catalyst was packed into a fixed-bed reactor at atmospheric pressure. The temperature was raised to 300 °C under a nitrogen atmosphere at 30 mL / min, and purged at this temperature for 0.5 hours. Then, the nitrogen atmosphere was turned off, and hydrogen chloride and oxygen were introduced into the catalyst bed at 200 mL / min and 50 mL / min, respectively, to react. The reactant hydrogen chloride and product chlorine were quantitatively analyzed by acid-base titration and iodometric titration, respectively. At this point, the equilibrium conversion rate of hydrogen chloride was 87%.

[0068] The results of the catalyst-catalyzed reaction of hydrogen chloride with oxygen to produce chlorine in the examples and comparative examples are shown in Table 1.

[0069] Table 1

[0070] Catalyst sources (examples and comparative examples) Hydrogen chloride conversion rate Example 1 86.8％ Example 2 86.7％ Example 3 86.9％ Example 4 86.9％ Example 5 86.8％ Comparative Example 1 20.3％ Comparative Example 2 20.8％ Comparative Example 3 19.9％ Comparative Example 4 3.1％

[0071] It can be seen that, compared with Comparative Examples 1-4, Examples 1-5 use the catalyst prepared in this invention to catalyze the reaction of hydrogen chloride with oxygen to produce chlorine gas. The reaction rate is high at a lower reaction temperature (300℃), and the conversion rate of hydrogen chloride is close to the equilibrium conversion rate of hydrogen chloride.

[0072] The specific embodiments described above are only used to explain and illustrate the present invention, and are not intended to limit the present invention. Any changes and substitutions made to the present invention without creative effort within the scope of the inventive concept and claims shall fall within the protection scope of the present invention patent.

Claims

1. A method for preparing chlorine gas by catalytic reaction of hydrogen chloride and oxygen using a catalyst, characterized in that, The catalyst is a ruthenium-based catalyst. The raw materials for preparing the catalyst include a ruthenium-type titanium dioxide catalyst support containing oxygen vacancies and an aqueous solution of ruthenium trichloride. The ruthenium-type titanium dioxide containing oxygen vacancies is obtained by subjecting anatase titanium dioxide to high-temperature ultraviolet treatment in an inert atmosphere. The inert atmosphere is any one of nitrogen, helium, and argon. The high-temperature ultraviolet treatment time is 0.5 to 6 hours, and the high temperature is 600 to 1000°C.

2. The method for preparing chlorine gas by catalytic reaction of hydrogen chloride and oxygen according to claim 1, characterized in that, The ultraviolet treatment is performed by irradiation with an ultraviolet lamp.

3. The method for preparing chlorine gas by catalytic reaction of hydrogen chloride and oxygen using a catalyst according to claim 1, characterized in that, The catalyst was prepared by impregnating ruthenium trichloride aqueous solution onto rutile titanium dioxide containing oxygen vacancies using an equal-volume impregnation method. After drying at 80-120°C for 6-24 hours, it was then heated at 250-350°C in an oxygen or air atmosphere for 6-16 hours.

4. The method for preparing chlorine gas by catalytic reaction of hydrogen chloride and oxygen using a catalyst according to claim 3, characterized in that, The concentration of the ruthenium trichloride aqueous solution is 0.05 g / mL.

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