A kind of preparation method of ordered mesoporous molybdenum carbide

Abstract

The invention relates to a preparation method of ordered mesopore molybdenum carbide, which belongs to the field of ordered mesopore material preparation. The preparation method comprises the following steps of adopting a hard template method, adopting saccharose as a carbon source and an SBA-15 molecular sieve as a template, stirring, carrying out ultrasound, drying and carbonizing, roasting, and acid pickling to obtain an ordered mesopore carbon material; then soaking the ordered mesopore carbon material into an ammonium molybdate solution (a molybdenum source), stirring, drying by distillation, and roasting to obtain an ordered mesopore carbon / molybdenum trioxide compound; mixing the ordered mesopore carbon / molybdenum trioxide compound with magnesium powder, and carrying out magnesiothermic reduction reaction in a tube furnace to obtain the ordered mesopore molybdenum carbide material. During the preparation process, the carbonization reduction temperature is greatly reduced; the molybdenum carbide prepared at a low temperature condition is concentrated in bore diameter and large in specific surface area; the rich mesoporous structure is beneficial to diffusion of reactants and exposure of active sites, so that the activity and the stability of a molybdenum carbide catalyst are improved. The preparation method is advanced in process, low in cost, easy for getting raw materials, reasonable in match ratio, and stable in products, and is an advanced method for preparing the ordered mesopore molybdenum carbide.

Description

technical field [0001] The invention relates to a preparation method of ordered mesoporous molybdenum carbide, belonging to the field of ordered mesoporous material preparation. Background technique [0002] As one of transition metal carbides, molybdenum carbide has the hardness and brittleness of covalent compounds, the high melting point of ionic crystals and the electromagnetic properties of transition metals, so molybdenum carbide is used as a wear-resistant, heat-resistant and corrosion-resistant material processing preparation. When molybdenum carbide is used as a catalyst, it shows good catalytic performance similar to noble metal platinum, and has excellent anti-sulfur, anti-poisoning, acid-base and acid-base corrosion resistance and ultra-high thermal stability. It is cheaper than precious metals in terms of price. It is widely used in catalytic hydrodesulfurization, catalytic hydrodenitrogenation, catalytic reforming reaction and fuel cell electrode reaction. ...

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Problems solved by technology

[0003] At present, the methods for preparing molybdenum carbide mainly include: (1) high-temperature carbonization method, which is carbonized by molybdenum oxide and C and CO at high temperature, such as patent CN1176312A, which uses carbon black as the carbon source, mixes it with molybdenum oxide, and directly roasts and carbonizes at high temperature , needs to be heated to 1600ºC, and the prepared molybdenum carbide has disadvantages such as small specific surface area, high energy consumption, and severe carbon on the surface of the catalyst.

(2) Cracking of metal precursors, using organic mixtures such as molybdate and hexamethylenetetramine or aniline to crack, this method is complicated to prepare, and the product will generate Mo 2 N impurity

However, there are few methods for preparing molybdenum carbide materials with ordered mesoporous structures. At the same time, in order to solve the problems of excessive reduction carbonization temperature, time-consuming and energy-consuming in the prior art, a relatively mild synthetic process condition is prepared. Ordered Mesoporous Molybdenum Carbide Materials

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