A kind of composite catalyst and preparation method thereof

Abstract

A composite catalyst and a preparation method thereof, the catalyst includes at least one carbon-composite transition metal carbide as an active component and silicon carbide as a carrier, when M represents the transition metal, MC is a transition metal carbide, The composite catalyst is represented as C-MC / SiC. The preparation method is as follows: first dissolve the transition metal salt to form a transition metal salt solution, and then mix it with silicon carbide; then evaporate the mixed solution to dryness, dry, and calcinate to obtain the precursor; finally, the precursor is in the reactor, microwave, carbonized, and cooled A composite catalyst is obtained. The invention can not only maximize the catalytic performance of the active components, but also greatly improve the stability of the catalyst, and contribute to the decomposition of hydrogen sulfide; alkali treatment of silicon carbide is more conducive to the absorption of hydrogen sulfide and break down. The raw materials of the catalyst are low in cost and easy to obtain, and the preparation method has simple steps, controllable process parameters and convenient operation.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a composite catalyst and a preparation method thereof. Background technique [0002] With the rapid development of society and economy in today's society, the country and the people pay more and more attention to environmental protection. Hydrogen sulfide is a by-product in the mining and processing of coal, oil and natural gas. If it is directly discharged into the environment without treatment, it will cause serious environmental pollution. Especially in recent years, gas fields with relatively high sulfur content have emerged continuously. In the petrochemical industry, hydrodesulfurization technology is widely used to produce high-quality fuel oil. Therefore, a large amount of hydrogen sulfide waste gas is produced every day. Corrosion of equipment and piping during transport. Hydrogen sulfide is a highly toxic gas with high chemical activity. When the concentr...

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Problems solved by technology

[0003] At present, the main method for industrially treating hydrogen sulfide waste gas is the Claus process, which is to incompletely oxidize hydrogen sulfide to generate water and sulfur, so that sulfur can be recovered, but hydrogen resources are wasted, because hydrogen sulfide waste gas cannot be recovered It is completely oxidized, and the tail gas is also accompanied by the generation of sulfur dioxide. Direct discharge into the atmosphere will cause secondary pollution. Therefore, it is very meaningful to find an effective way to directly decompose hydrogen sulfide into sulfur and hydrogen.

[0004] In recent years, there are many shortcomings in the method of directly decomposing hydrogen sulfide to generate hydrogen and sulfur: excessive energy consumption, expensive materials, low catalyst decomposition efficiency and easy deactivation, harsh decomposition reaction conditions, etc., for example: Furhad et al. Directly decompose hydrogen sulfide without adding a catalyst. It is found that the conversion rate of hydrogen sulfide is 35.6% at a temperature of 1200°C and a pressure of 0.1Mpa. The rate can reach 65.8%. Although this process realizes the direct decomposition of hydrogen sulfide, the required temperature is too high and consumes a lot of energy; Zhao et al. used pulsed corona discharge plasma reactor to explore the direct decomposition of hydrogen The minimum energy consumption of each hydrogen sulfide molecule is 17 eV, but it cannot handle the high concentration of hydrogen sulfide gas, which also limits the industrial application; Ma Guijun et al. 2+ When doped into ZnS, the decomposition rate of hydrogen sulfide can reach 17 μmol / h, but the catalyst is easily deactivated, the utilization rate of visible light is extremely low, and the decomposition efficiency is not high

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