Preparation method of high-thermal-stability NiCo/SiO2 core-shell catalyst

Abstract

The invention relates to a preparation method of a high-thermal-stability NiCo / SiO2 core-shell catalyst. The method comprises the following steps: 1) mixing a nickel source, a cobalt source, a surfactant and a solvent to obtain a first mixed solution, heating the first mixed solution under the atmosphere of inert gas, cooling to room temperature, adding ethanol to settle a product, centrifugally washing with a mixed solution of ethanol and cyclohexane, and dissolving into cyclohexane to seal up to obtain NiCo alloy nanoparticles; 2) mixing the cyclohexane, a nonionic surfactant and ammonia water to obtain a second mixed solution, adding the cyclohexane containing the NiCo alloy nanoparticles into the second mixed solution, adding a silicon source after stirring, performing stirring reaction, settling a solid product by using methanol, centrifugally washing, drying a sample after washing, and roasting at high temperature to prepare the high-thermal-stability NiCo / SiO2 core-shell catalyst. Compared with the prior art, the core-shell structure NiCo / SiO2 catalyst has high reaction activity and heat stability, and enables the reaction to operate stably for 1000 hours or above.

Description

technical field [0001] The invention relates to a catalyst material, in particular to a high thermal stability NiCo / SiO 2 Process for the preparation of core-shell catalysts. Background technique [0002] Methane and carbon dioxide are two major greenhouse gases, and they are also important chemical raw materials. Their effective development and utilization is the key development direction of pollutant resource utilization, among which CH 4 -CO 2 Thermal reforming is an effective way to produce synthesis gas. The H in the synthesis gas produced by this process 2 The / CO ratio is about 1, which can be directly used as raw material gas for oxo synthesis and Fischer-Tropsch synthesis, making up for the deficiency of high hydrogen-carbon ratio in the synthesis gas produced by steam reforming of methane. At the same time, CH 4 -CO 2 Thermal reforming reactions can be used as energy storage media and energy transport. [0003] Transition metal (Fe, Co and Ni, etc.) catalysts...

AI Technical Summary

Problems solved by technology

The second is the problem of carbon deposition. Due to the high temperature reaction, it is easy to produce CO 2 The disproportionation reaction and CH 4 The cracking reaction of the catalyst leads to carbon deposition, and with the agglomeration of the active sites of the catalyst, the carbon deposition is accelerated. Obviously, the key to ensuring the stability of the catalyst is to inhibit the agglomeration of the active sites

[0005] However, the dispersibility of the core-shell structure nanoparticle catalyst obtained in the above-mentioned patent is relatively poor, and the reaction life of the core-shell structure nanoparticle catalyst obtained in the above-mentioned patent is not very long.

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