Ammonia synthesis magnetite catalyst precursor

Thereout, it is found that the catalyst has the highest activity among all the fused iron catalysts for ammonia synthesis when its chemical composition and crystal structure of the precmsor are those of wiistite (Fei xO)- It is called Fei xO or wiistite based ammonia sjmthesis catalysts, where the defect concentration x of iron ion is 0.04 experimental results break through the classical conclusion that lasted for more than 80 years, namely the catalyst has the best activity when its chemical composition and crystal structure of the precursor are most close to those of magnetite. It also provides a new approach for a novelcat-alytic system — wiistite Fei xO system for improving the performances of the fused iron catalysts. 

Pig. 7.31 Phase analysis of a technical catalyst precursor for ammonia synthesis K = KHC03, C = CaFe306, M = magnetite (Magnetite reflections are indexed in the upper diagram)... 

The discovery of the Fei xO based catalyst with wiistite structure was a breakthrough of the classical theory on the oxide precursor and the activity is higher than the best magnetite-based catalysts in the world. This invention indicates an essential improvement on the research for ammonia synthesis catalysts since 1913. It is a chance for further progress of iron catalyst and aroused much attention of the scientists in the field. At present, the Fei xO based catalyst has been widely used in industry. 

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