Preparation method of polyhedral transition metal carbide particles for catalytic material

Abstract

The invention discloses a preparation method of polyhedral transition metal carbide particles for a catalytic material, wherein the preparation method comprises the following steps: step 1, ball-milling and uniformly mixing aluminum powder, transition metal powder and a carbon source, and pressing into a preparation block, wherein the transition metal powder comprises titanium powder, tantalum powder, niobium powder, zirconium powder, tungsten powder and / or vanadium powder, the content of the aluminum powder is 40-70 wt.%, and the molar ratio of the carbon source to the transition metal powderis 0.5-0.8; step 2, heating the preparation block in a vacuum or argon protection state, and cooling to room temperature; and step 3, soaking with hydrochloric acid to remove an aluminum matrix to obtain the polyhedral transition metal carbide particles. According to the method provided by the invention, the nano polyhedral transition metal carbide particles are prepared through medium-low temperature and high temperature combined rapid cooling, and the submicron and micron polyhedral transition metal carbide particles are prepared through secondary heating.

Description

technical field [0001] The invention relates to the technical field of ultra-high temperature ceramic materials, and more specifically, the invention relates to a method for preparing polyhedral transition metal carbide particles used for catalytic materials. Background technique [0002] Transition metal carbides have the advantages of high melting point, high hardness, good electrical conductivity and chemical stability, and are widely used as coating materials, mechanical parts and reinforcing phases in composite materials. Transition metal carbides have attracted extensive attention in catalytic applications since the first report by Levy and Boudart in 1973 that WC possessed Pt-group metal-like catalytic properties in neopentane isomerization. When transition metal carbide particles are used as the reinforcing phase of composite materials, it is generally desired that the particle shape is nearly spherical or spherical. When the particle shape is a regular polyhedron, i...

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Problems solved by technology

[0003] The preparation method of transition metal carbides in the prior art is a self-propagating high-temperature preparation technology. However, in the process of preparing transition metal carbides in this method, due to the fast combustion reaction speed, the release of a large amount of heat and the uneven temperature field, resulting in The preparation process cannot be controlled, making the prepared particle size uneven, and may even lead to irregular shapes

[0004] The current problem is that the large-scale controllable preparation of transition metal carbides cannot be achieved, and the particle size, morphology and specific crystal planes cannot be well controlled, which limits the practical application of transition metal carbides in catalysis. Therefore, It is urgent to develop a carbide particle with regular shape, uniform size and high catalytic activity.

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