Sphere Of Fe <sub> 1-x </ Sub> O-based Catalyst For Ammonia Synthesis Performance Study

Spherical Fe1-x O-based catalysts for ammonia synthesis have been studied in this thesis. The structural characters and reducing behavior of them have been focused in the study to explore the reason of their good performance in reduction. A classical equation is modified according to the contacting-sphere model so that it can explain the process of the reduction of the Fe1-x O-based catalysts.First, XRD, SEM and MBS are employed to study the oxidation form of the Fe1-x O-based catalysts. The results show that, in the spherical catalyst AQ-1, the crystal grains are finer and promoters more well-proportioned than in other amorphous catalysts. When Ca, Zr occur in the catalysts they exist in the form of CaZr4O9.Second, the reducing behaviors of the Fe1-x O-based catalysts have been studied on TG. It's found that the introduction of Zr can lower the temperature that the catalysts begin to be reduced and the temperature that their reducing velocities reach maximum. The reasons of good reducing performances of the spherical Fe1-x O-based catalysts have been discussed comprehensively in the thesis. A modification has been made in the kinetic equation of the reducing process of ammonia-synthesis catalysts according to the contacting-sphere model. This modified model can be applied to explain the reducing process of the Fe1-x O-based catalysts at general temperatures. Through the research of the maximum of reduction degree, we provide a reasonable reducing programme of spherical Fe1-x O-based catalysts.