Substituted SrFeO₃ as robust oxygen sorbents for thermochemical air separation: correlating redox performance with...

Area of Science:

• Materials Science
• Chemical Engineering
• Computational Chemistry

Background:

• Thermochemical air separation using oxide sorbents offers high energy efficiency.
• Improving sorbent performance requires understanding structure-property relationships.

Purpose of the Study:

• Investigate the impact of A and B site dopants on SrFeO3 perovskites for oxygen sorbent applications.
• Establish correlations between dopant-induced structural changes and oxygen uptake/release properties.

Main Methods:

• Systematic investigation of SrFeO3 perovskites with various dopants.
• Utilized Density Functional Theory (DFT) calculations to determine oxygen vacancy formation energy and other properties.
• Conducted experimental studies to validate DFT predictions and assess long-term stability.

Main Results:

• A direct correlation was found between DFT-calculated oxygen vacancy formation energy and oxygen release temperature.
• Dopants like Barium (Ba) and Manganese (Mn) effectively tune the redox properties and enhance oxygen capacity.
• The Mn-doped sample demonstrated remarkable stability, retaining over 97% capacity after 1000 cycles.

Conclusions:

• DFT calculations are effective for guiding the selection of oxygen sorbents.
• A systematic approach correlating oxygen storage capacity with compositional properties and vacancy formation energies was developed.
• Combining DFT with experimental validation offers a promising strategy for designing superior sorbents for thermochemical air separation.