Integral porous carbon-silicon carbide composite material, and preparation method and application thereof

Abstract

The invention discloses an integral porous carbon-silicon carbide composite material, and a preparation method and an application thereof. The preparation method comprises the following steps: fully stirring and dispersing silicon carbide powder, silicon powder, carbon-containing powder and a sintering aid in water, preparing a green body by using an ice crystal pore formation technology or an organic polymer foam template pore formation technology, and carrying out high temperature sintering to prepare an integral silicon carbide core; and generating a stable carbon-containing shell with high mechanical strength in the pore channels of the porous SiC core through an in-situ generation technology or a carbon-containing precursor polymerization carborization technology. The composite material has the characteristics of high specific surface area, easy activation surface, acid and alkali corrosion resistance, good heat and electricity conduction property, high and stable mechanical strength, low gas passing pressure drop and low preparation cost, can be used as a metal catalyst loading carrier, or can be directly used as a nonmetal catalyst, so the defects of easiness in pulverization, easiness in obstruction, difficulty in molding and high price of present industrial active carbon catalysis carriers are avoided.

Description

technical field [0001] The invention relates to a monolithic porous carbon-silicon carbide composite material and its preparation method, more specifically, the invention relates to a material with high mechanical strength and high Thermally and electrically conductive monolithic composite material with carbon as the shell and porous silicon carbide as the core and its preparation method. The carbon-silicon carbide composite material not only has a high specific surface area of ​​a hierarchical porous structure and a surface that is easily activated or modified by chemicals, but also has stable overall mechanical strength and controllable physical and chemical properties. Background technique [0002] Activated carbon is widely used as an industrial catalyst carrier, such as the use of activated carbon to support noble metals Pt, Pd, etc. in hydrogenation reactions. Activated carbon has a high specific surface area (>1000m 2 / g) and very low bulk density (0.5-0.9g / cm 3...

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Problems solved by technology

However, this patent is limited to the chemical treatment of SiC powder. Although it has stable mechanical strength and high specific surface area, it does not form a monolithic structure, so it cannot reflect the good thermal and electrical conductivity of SiC.

In the Chinese patent CN102814188 published in 2014 by the Zhang Jinsong research team of the Institute of Metal Research, Chinese Academy of Sciences, an activated carbon layer / foamed silicon carbide structure catalyst and its preparation method are mentioned, but this method only applies the carbon layer to the porous foam by coking the additive. On silicon carbide, there is no close connection between silicon carbide and carbon layers, which leads to the resistance of heat transfer between them. At the same time, the porous silicon carbide foam they use is mainly sintered by oxides, and the overall electrical conductivity and thermal conductivity are better than silicon carbide. are greatly reduced

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