Catalytic effect of plasma in lowering the reduction temperature of $Fe_{2}O_{3}$

TL;DR

This study demonstrates that microwave-driven argon atmospheric pressure plasma can effectively lower the reduction temperature of hematite by converting it to magnetite, with plasma treatment confirmed as the key factor through various surface analyses.

Contribution

It introduces a novel plasma-assisted method for rapid regeneration of iron oxides, enhancing catalytic properties without sintering, under ambient conditions.

Findings

Plasma treatment converts hematite to magnetite.

Reduction temperature is significantly lowered by plasma.

Surface analysis confirms chemical state change.

Abstract

Atmospheric pressure plasma (APP) generates highly reactive species that are useful for surface activations. We demonstrate a fast regeneration of iron oxides, that are popular catalysts in various industrial processes, using microwave-driven argon APP under ambient condition. The surface treatment of hematite powder by the APP with a small portion of hydrogen (0.5%) lowers the oxide's reduction temperature. A near-infrared laser is used for localized heating to control the surface temperature. Controlled experiments without plasma confirm the catalytic effect of the plasma. Raman, XRD, SEM, and XPS analyses show that the plasma treatment changed the chemical state of the hematite to that of magnetite without sintering.