A kind of ruthenium-based catalyst based on associative hydrogenation and chemical chain ammonia synthesis route and its preparation method and application

Abstract

The invention belongs to the field of preparation of catalyst materials, and in particular relates to a Ru-based ammonia synthesis catalyst and its preparation method and application. In the present invention, the metal hydride is used as a carrier, the Ru-based catalyst precursor is synthesized by loading, the metal nitride is used as a co-catalyst, and the Ru-based catalyst containing the auxiliary agent is synthesized by physical grinding, and then dried to prepare the Ru-based catalyst. And study its ammonia synthesis reaction performance. This type of catalyst includes two pathways of associative hydrogenation and chemical chain ammonia synthesis, breaking the restrictive relationship existing in the traditional ammonia synthesis reaction. When the mass ratio of LaN is 3wt.%, the composite catalyst has excellent low-temperature ammonia synthesis catalytic performance and high thermal stability. The preparation method of the catalyst provided by the invention is simple, and the catalyst has high mechanical strength, so it presents a good industrial application prospect in the ammonia synthesis reaction and has obvious industrial application value.

Description

technical field [0001] The invention relates to the field of preparation of catalyst materials, in particular to a Ru-based catalyst based on the path of associative hydrogenation and chemical chain synthesis of ammonia, its preparation method and application. Background technique [0002] Ammonia (NH 3 ) as an important fertilizer and chemical raw material plays a vital role in maintaining human civilization. And recently, due to the high hydrogen storage capacity (17.7wt.%) of ammonia, the energy density (3KW·h·kg -1 ) and transportation convenience, it is considered as an emerging carbon-free energy carrier (Journal of Materials Chemistry, 2008, 18(20): 2304-2310). At present, the industrial synthesis of ammonia is mainly through the Haber-Bosch process using molten Fe-based catalysts to generate ammonia gas at high temperature (400–600°C) and high pressure (20–40MPa). (ACS Catalysis, 2016, 6(11):7577-7584), resulting in a large amount of energy loss. Therefore, ther...

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Problems solved by technology

Because the ammonia synthesis reaction is an exothermic reaction limited by thermodynamic equilibrium, as the reaction temperature increases, it is kinetically beneficial to increase the NH 3 However, the increase of temperature caused the equilibrium conversion rate of ammonia synthesis reaction to decrease significantly, the root cause of which is the transition state NH x There is a limiting relationship between and adsorption energy, i.e. strong adsorption of N atoms means lower N 2 Dissociation energy, higher NH x Adsorption energy (Nature chemistry, 2017, 9(1):64)

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