A kind of preparation method of carbon nano-cage coupled molybdenum carbide quantum dot nanocomposite material

Abstract

The invention discloses a preparation method of carbon nano-cage coupled molybdenum carbide quantum dot nano-composite material, comprising the following steps: (1), dissolving acid and ammonium molybdate with a mass ratio of 100:(14-25) in deionized After forming 26~45g / L ammonium molybdate solution in water, stir for 3~4h to obtain molybdenum-containing hydrogel, and then place it in an oven at 80~120℃ to dry for 0.5~5h to obtain molybdenum xerogel precursor; ( 2) Place the precursor in a tube furnace, heat up at a rate of 5°C / min, and perform constant temperature treatment under an inert atmosphere of 850-950°C for 2 hours to obtain a composite material of carbon nanocage-dispersed molybdenum carbide quantum dots. The carbon nano-cage-dispersed molybdenum carbide quantum dot composite material prepared by the invention has the advantages of simple preparation process, convenient operation and easy control of process parameters, thereby obtaining a novel carbide composite material, which can be applied to the field of hydrogen production catalysis.

Description

technical field [0001] The invention relates to the technical field of catalytic materials, in particular to a preparation method of a carbon nano-cage coupled molybdenum carbide quantum dot nano-composite material. Background technique [0002] Metal carbides are a new class of functional materials with high hardness, high melting point, good thermal stability and corrosion resistance, and have been used in many fields. In the 1990s, Ledoux et al. reported that metal carbides have noble metal-like properties. It is believed that in metal carbides, carbon atoms are inter-filled in the metal lattice, causing changes in electron density, making lattice parameters larger, and lattice spacing. The d-band shrinks and the density of d-electrons in the Fermi state increases, resulting in surface properties and absorption properties similar to those of noble metals. In recent years, carbides, especially molybdenum carbide, have attracted extensive attention as a new class of cataly...

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Problems solved by technology

The method is simple and easy to empty and the product is relatively pure, but the method easily leads to carbonization of the catalyst surface area, and the specific surface area of ​​the obtained molybdenum carbide is small; Medium reaction, the product obtained by this method has a larger specific surface area, but the reaction temperature is usually higher; 3, solvothermal reduction method, this method is to use a substance with strong reducing ability (KBH 4 ) to reduce molybdenum oxide to molybdenum carbide. This method is simple and easy to control, and the temperature is low, but the product is not pure; 4. Metal precursor cracking method is to use metal organic compounds and ammonium molybdate and hexamethylenetetramine The mixture is produced by pyrolysis at high temperature, but the preparation of the precursor is complicated and the particles obtained are relatively large

In addition, there are reports of CVD, hydrothermal method, ultrasonic method, microwave method, etc., but these methods also have the problems of small yield, insufficient reaction, large product particles, and impure products.

The above methods are limited and have their own characteristics, so there are big deficiencies in practical application, especially in the mass production of catalysts.

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