Study of the Iron Catalyst for Ammonia Synthesis by Chemical Potential Programmed Reaction Method

Abstract

A new method, entitled chemical potential programmed reaction, for determining the physicochemical properties of iron ammonia synthesis catalyst has been proposed. Two model reactions were applied: nitriding of the iron catalyst and reduction of the obtained nitrides. Measurements of the rates of those reactions were carried out at 350 °C in a differential tubular reactor. The reactor is equipped with a system that allows us to perform simultaneous thermogravimetric measurements and a catharometric system to determine hydrogen concentration in the gas phase. The reactor was fed with a mixture of ammonia and hydrogen of varying composition, which was changing in a controlled way. Different accelerations of the nitriding potential change were applied. During the processes of nitriding of nanocrystalline iron and reduction of the obtained nanocrystalline iron nitrides rates of these processes were measured. The minimum nitriding potential, at which the phase transformation of nanocrystallites of a certain si...