(La1−xCax)MnO3−δ (x = 0, 0.2, 0.3, 0.4) Perovskites as Redox Catalysts in Chemical Looping Hydrogen Production Process: The Relation between Defect Chemistry and Redox Performance

Moschos, Moschos; Evdou, Antigoni; Zaspalis, Vassilios

doi:10.3390/catal14070431

Open AccessArticle

(La_1−xCa_x)MnO_3−δ (x = 0, 0.2, 0.3, 0.4) Perovskites as Redox Catalysts in Chemical Looping Hydrogen Production Process: The Relation between Defect Chemistry and Redox Performance

by

Moschos Moschos

¹,

Antigoni Evdou

²

and

Vassilios Zaspalis

^1,2,*

¹

Department of Chemical Engineering, Aristotle University of Thessaloniki, University Campus, 54124 Thessaloniki, Greece

²

Chemical Process Engineering Research Institute, Center for Research and Technology-Hellas, Thermi, 57001 Thessaloniki, Greece

^*

Author to whom correspondence should be addressed.

Catalysts 2024, 14(7), 431; https://doi.org/10.3390/catal14070431

Submission received: 4 June 2024 / Revised: 2 July 2024 / Accepted: 3 July 2024 / Published: 6 July 2024

(This article belongs to the Section Nanostructured Catalysts)

Download

Browse Figures

Versions Notes

Abstract

The interaction between point defects in (La_1−xCa_x)MnO_3−δ (x = 0, 0.2, 0.3, 0.4) perovskites and their redox catalytic properties in a three-reactor chemical looping hydrogen production process is investigated. During the reduction step with CH₄, the behavior of the materials is extrinsically determined and strongly depends on the Ca content. At small oxygen deficiencies, CH₄ becomes oxidized to CO₂. As the deficiency increases, partial oxidation to CO and H₂ at a molar ratio of approximately 2 is favored. During the water-splitting step, the dependency on the Ca content is much weaker since it is intrinsically determined by the Mn²⁺→Mn³⁺ oxidation with simultaneous annihilation of oxygen vacancies that are not required to compensate for the extra negative charge of the Ca dopant. Hydrogen productivities in the order of 13 cm³ (STP) H₂/g solid could be achieved during the water-splitting step at 1000 °C. The materials exhibited reproducible catalytic behavior during 10 cycles of the complete three-step process and were found to retain their perovskite structure.

Keywords: (La_1−xCa_x)MnO_3−δ; perovskites; redox catalysts; chemical looping hydrogen production; defect chemistry

Graphical Abstract

Share and Cite

MDPI and ACS Style

Moschos, M.; Evdou, A.; Zaspalis, V. (La_1−xCa_x)MnO_3−δ (x = 0, 0.2, 0.3, 0.4) Perovskites as Redox Catalysts in Chemical Looping Hydrogen Production Process: The Relation between Defect Chemistry and Redox Performance. Catalysts 2024, 14, 431. https://doi.org/10.3390/catal14070431

AMA Style

Moschos M, Evdou A, Zaspalis V. (La_1−xCa_x)MnO_3−δ (x = 0, 0.2, 0.3, 0.4) Perovskites as Redox Catalysts in Chemical Looping Hydrogen Production Process: The Relation between Defect Chemistry and Redox Performance. Catalysts. 2024; 14(7):431. https://doi.org/10.3390/catal14070431

Chicago/Turabian Style

Moschos, Moschos, Antigoni Evdou, and Vassilios Zaspalis. 2024. "(La_1−xCa_x)MnO_3−δ (x = 0, 0.2, 0.3, 0.4) Perovskites as Redox Catalysts in Chemical Looping Hydrogen Production Process: The Relation between Defect Chemistry and Redox Performance" Catalysts 14, no. 7: 431. https://doi.org/10.3390/catal14070431

APA Style

Moschos, M., Evdou, A., & Zaspalis, V. (2024). (La_1−xCa_x)MnO_3−δ (x = 0, 0.2, 0.3, 0.4) Perovskites as Redox Catalysts in Chemical Looping Hydrogen Production Process: The Relation between Defect Chemistry and Redox Performance. Catalysts, 14(7), 431. https://doi.org/10.3390/catal14070431

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Menu

(La_1−xCa_x)MnO_3−δ (x = 0, 0.2, 0.3, 0.4) Perovskites as Redox Catalysts in Chemical Looping Hydrogen Production Process: The Relation between Defect Chemistry and Redox Performance

Abstract

Share and Cite

Article Metrics

Article Access Statistics

Further Information

Guidelines

MDPI Initiatives

Follow MDPI