Method for preparing tungsten-carbide powder through low-temperature combustion synthesis

A low-temperature combustion synthesis and tungsten carbide technology, which is applied in the direction of carbide, tungsten/molybdenum carbide, etc., can solve the problems of tungsten carbide powder, such as no report, low output, and difficulty in industrialization, and achieve low cost and high distribution. Uniform, full contact effect

Inactive Publication Date: 2012-09-19
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The low-temperature combustion synthesis process equipment is simple, fast and convenient, and can overcome other disadvantages such as harsh process conditions, low output, and difficulty in industrialization
So far, there have been no reports on the preparation of tungsten carbide powder by low-temperature combustion synthesis

Method used

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  • Method for preparing tungsten-carbide powder through low-temperature combustion synthesis
  • Method for preparing tungsten-carbide powder through low-temperature combustion synthesis
  • Method for preparing tungsten-carbide powder through low-temperature combustion synthesis

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Weigh 0.015mol of ammonium tungstate, 0.1mol of urea, 0.2mol of nitric acid, and 0.2mol of glucose, add 150ml of deionized water, and mix well in a 1000ml beaker. Place the mixed solution on a closed electric furnace to heat, turn on the electric furnace to the maximum power, and stir while heating. When the water in the solution is almost evaporated to dryness and becomes viscous, stop stirring, and stop heating when the solution starts to condense, smoke and ignite automatically. After the solution was ignited, a fluffy mixture was obtained. After the mixture has cooled, take the mixture out and grind it into a powder in a mortar. The obtained powder was put into a square graphite boat, and carbonized in a resistance furnace protected by argon gas. The carbonization temperature was 900°C, and the heating rate was 3°C / min.

Embodiment 2

[0018] Weigh 0.015mol of ammonium tungstate, 0.1mol of urea, 0.2mol of nitric acid, and 0.2mol of glucose, add 150ml of deionized water, and mix well in a 1000ml beaker. Place the mixed solution on a closed electric furnace to heat, turn on the electric furnace to the maximum power, and stir while heating. When the water in the solution is almost evaporated to dryness and becomes viscous, stop stirring, and stop heating when the solution starts to condense, smoke and ignite automatically. After the solution was ignited, a fluffy mixture was obtained. After the mixture has cooled, take the mixture out and grind it into a powder in a mortar. The obtained powder was put into a square graphite boat, and carbonized in a resistance furnace protected by argon gas. The carbonization temperature was 1000°C, and the heating rate was 3°C / min. The minimum particle size of tungsten carbide is 1.53μm, and the average particle size is 12.11μm.

Embodiment 3

[0020] Weigh 0.015mol of ammonium tungstate, 0.1mol of urea, 0.2mol of nitric acid, and 0.2mol of glucose, add 150ml of deionized water, and mix well in a 1000ml beaker. Place the mixed solution on a closed electric furnace to heat, turn on the electric furnace to the maximum power, and stir while heating. When the water in the solution is almost evaporated to dryness and becomes viscous, stop stirring, and stop heating when the solution starts to condense, smoke and ignite automatically. After the solution was ignited, a fluffy mixture was obtained. After the mixture has cooled, take the mixture out and grind it into a powder in a mortar. The obtained powder was put into a square graphite boat, and carbonized in an argon-protected resistance furnace, the carbonization temperature was 1100°C, the heating rate was 3°C / min, and after holding for 6 hours, it was slowly cooled with the furnace to obtain tungsten carbide powder. The minimum particle size of tungsten carbide is 1....

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Abstract

The invention provides a method for preparing tungsten-carbide powder through low-temperature combustion synthesis, which belongs to the technical field of low-temperature combustion synthesis. The method is characterized in that ammonium tungstate is served as a tungsten source; water-soluble organic matters such as citric acid, glucose, cane sugar and the like are served as a carbon source; and urea and nitric acid are added. The method comprises the following steps: A. the ammonium tungstate, the carbon source, the urea and the nitric acid are prepared into mixed solution according to certain molar ratio, and the mixed solution is heated on a closed electric furnace to be concentrated to be sticky, so as to obtain fluffy mixture; and B. after the fluffy mixture is ground, carbonization reaction is performed in a resistance furnace which is protected by feeding argon, the reaction temperature is controlled within a range of 900 to 1100 DEG C, the reaction time is 4 to 12 hours, and final finished product tungsten-carbide powder is obtained after the reaction. The tungsten source and the carbon source are uniformly distributed, contact is sufficient, the micron-sized tungsten-carbide powder is obtained at low temperature, the cost of raw material is low, the preparation operation is simple, and the method has the potential for large-scale promotion and application.

Description

[0001] technical field [0002] The invention belongs to the technical field of low-temperature combustion synthesis, and in particular relates to a preparation method of tungsten carbide powder suitable for gas diffusion electrode catalysts. Background technique [0003] Tungsten carbide (WC) is hcp structure, stable at low temperature, insoluble in water, hydrochloric acid and sulfuric acid. WC is a non-precious metal catalyst with excellent stability and oxidation resistance, and has strong resistance to carbon monoxide, hydrocarbons, and hydrogen sulfide poisoning. WC is a catalytic material with great research value and development prospect. Existing studies have shown that WC has the following surface structure and electronic properties: the surface atomic arrangement on the main crystal surface of WC and Pt is similar; the electronic density of states near the Fermi level is relatively high; due to the influence of C, W 5d in WC The electrons are no longer all share...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/34C01B32/949
Inventor 李平曲选辉崔利群张伟娜李云龙翟富强万琦尹海清
Owner UNIV OF SCI & TECH BEIJING
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