Theoretical insights into the oxygen supply performance of a-Fe2O3 in the chemical-looping reforming of methane

The chemical looping reforming of methane to syngas is of great significance to the sustainable development of energy and environment, where the oxygen carrier (OC) is the core element of this technology. To study the oxygen migration properties of OCs and the matching problem of oxygen migration rate with the surface catalytic reaction rate, we present a theoretical study by taking the abundant and cheap alpha-Fe2O3 as the model OC. It is found that the migration rate of lattice oxygen and the dissociation of methane will be enhanced as the concentration of surface oxygen vacancy increases. By comparing the oxygen migration rate with the methane dissociation rate, we reveal that the two rates can match well at a low surface oxygen vacancy concentration, which is the key to the selective production of syngas. Lower or higher surface oxygen vacancy concentration will lead to the products towards carbon dioxide or coke. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

In this study, the oxygen migration properties of oxygen carriers (OCs) and the matching problem of oxygen migration rate with the methane dissociation rate were investigated using theoretical analysis. It was found that the migration rate of lattice oxygen and the dissociation of methane can be well matched at a low surface oxygen vacancy concentration, which is crucial for the selective production of syngas.