A kind of ruthenium-based ammonia synthesis catalyst with cerium oxide as carrier

Abstract

The invention relates to a ruthenium-based ammonia synthesis catalyst using cerium oxide as a carrier. The catalyst is prepared by the following method: conducting thermal treatment on a ruthenium nitrosyl nitrate catalyst supported on cerium oxide in a mixed gas containing NO, and then conducting reduction, so as to obtain the catalyst. The invention has the advantages that in the thermal treatment process, existing NO influences rapid decomposition and reduction of ruthenium nitrosyl nitrate, inhibits sintering growth of ruthenium metal particles, improves dispersing of the ruthenium metal particles, and promotes interaction of the ruthenium metal and the cerium oxide carrier, so that the catalyst of the invention has better ammonia synthesis properties, and under same conditions, the catalyst of the invention has an ammonia synthesis reaction rate substantially higher than a cerium-oxide-supported ruthenium catalyst prepared by a traditionally calcining method, a gas-phase reductionmethod and a liquid-phase reduction method, and has better application prospect.

Description

technical field [0001] The invention relates to a preparation method of a ruthenium-based catalyst for ammonia synthesis using nitrogen and hydrogen in the ammonia synthesis industry in the field of chemical fertilizers, in particular to a ruthenium-based ammonia synthesis catalyst with cerium oxide as a carrier and a preparation method thereof. Background technique [0002] The traditional ammonia synthesis catalyst is a molten iron catalyst, which has disadvantages such as high temperature, high pressure and high energy consumption in the production process, which is not conducive to energy saving and consumption reduction in the ammonia synthesis industry. Ruthenium catalyst is known as the second-generation ammonia synthesis catalyst because of its excellent performance, but so far only the ruthenium catalyst supported by activated carbon has achieved industrial application, but the activated carbon support will generate methane under high temperature and high pressure am...

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Problems solved by technology

However, heat treatment in an oxygen-containing atmosphere or a hydrogen-containing atmosphere tends to reduce the ruthenium metal precursor too quickly and increase the catalyst particle size, which is not conducive to the ammonia synthesis activity of the ruthenium catalyst.

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