Ru-based catalyst based on association hydrogenation and chemical-looping synthetic ammonia path as well as preparation method and application of Ru-based catalyst

Abstract

The invention belongs to the field of preparation of catalyst materials, and particularly relates to a Ru-based synthetic ammonia catalyst as well as a preparation method and an application thereof. According to the invention, metal hydride is used as a carrier, a Ru-based catalyst precursor is synthesized by loading, a metal nitride is used as a cocatalyst, a Ru-based catalyst containing an auxiliary agent is synthesized by adopting a physical grinding method, then the Ru-based catalyst is prepared by drying, and the ammonia synthesis reaction performance of the Ru-based catalyst is studied.The catalyst comprises two paths of associated hydrogenation and chemical-looping synthesis ammonia, and breaks through the restrictive relationship in the traditional synthesis ammonia reaction. Whenthe mass ratio of LaN is 3 wt.%, 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 mechanical strength of the catalyst is relatively high, so that the catalyst has a good industrial application prospect in an ammonia synthesis reaction and hasan 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 (3 KW·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 (20–40 MPa). (ACS Catalysis, 2016, 6(11):7577-7584), resulting in a large amount of energy loss. Therefore, th...

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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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