Ruthenium system ammonia synthesis catalyst using graphitization activated carbon as carrier and preparation method of catalyst

Abstract

The invention discloses a ruthenium system ammonia synthesis catalyst using a graphitization activated carbon as a carrier and a preparation method of the catalyst. The ruthenium system ammonia synthesis catalyst is as shown in Ru-X-K / AC, wherein Ru represents that a precursor is a water-soluble chloride-free ruthenium complex or ruthenium chloride; X represents a metal adjuvant and is one or more of nitrate, acetate, carbonate, metallic oxide and hydroxide of rare-earth metal or alkaline-earth metal; AC represents a graphitization activated carbon carrier, and K represents a kalium adjuvant, namely potassium hydroxide, potassium nitrate, potassium acetate and potassium carbonate; the graphitization activated carbon which has the advantages of high specific surface area, high graphitization and low oxygen content is utilized as the carrier, and the ammonia synthesis catalyst is prepared through steps such as secondary graphitization of graphitization activated carbon, preparation of precursor and preparation of catalyst. The ruthenium system ammonia synthesis catalyst has the advantages that the graphitization activated carbon has large specific surface area and pore volume, enough place is provided for metal segregation, the graphitization degree is high, the oxygen content is low, the methanation resisting capacity of the catalyst is strong, and the stability is good.

Description

technical field [0001] The invention belongs to the technical field of ammonia synthesis catalyst preparation, and more specifically relates to a ruthenium-based ammonia synthesis catalyst with graphitized activated carbon as a carrier and a preparation method thereof. Background technique [0002] In the field of ammonia synthesis catalysts, ruthenium-based ammonia synthesis catalysts based on activated carbon or graphitized activated carbon as a carrier have high initial activity, but this type of catalyst is prone to methanation reaction and has poor thermal stability. The performance of the catalyst will be affected by long-term use. Influence. Early documents and patents aimed to improve the stability of ruthenium-based ammonia synthesis catalysts mainly by increasing the degree of graphitization of the carrier. However, if the degree of graphitization of the carrier is too high, it is difficult to expand the pores of the graphitized carrier. It is not conducive to the...

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Problems solved by technology

[0003] The object of the present invention is to provide a kind of ruthenium series ammonia synthesis catalyst and preparation method thereof with graphitized activated carbon as the carrier, for solving the problem that the catalyst prepared by common preparation method is easy to methanate and has poor thermal stability, and prepares high Active and highly stable ruthenium-based ammonia synthesis catalyst