W-doped Lanthanum Molybdenum Oxide/Lithium-Sodium-Potassium Carbonate Composite Membranes for Carbon Dioxide Permeation

Midilane S Medina; Sabrina G M Carvalho; Francisco N Tabuti; Eliana N S Muccillo; Fábio C Fonseca; Reginaldo Muccillo

doi:10.3390/ma16145128

W-doped Lanthanum Molybdenum Oxide/Lithium-Sodium-Potassium Carbonate Composite Membranes for Carbon Dioxide Permeation

Materials (Basel). 2023 Jul 20;16(14):5128. doi: 10.3390/ma16145128.

Authors

Midilane S Medina¹, Sabrina G M Carvalho¹, Francisco N Tabuti², Eliana N S Muccillo¹, Fábio C Fonseca², Reginaldo Muccillo¹

Affiliations

¹ Center of Science and Technology of Materials, Energy and Nuclear Research Institute, Sao Paulo 05508-000, Brazil.
² Center of Fuel Cells and Hydrogen, Energy and Nuclear Research Institute, Sao Paulo 05508-000, Brazil.

Abstract

Single-phase tungsten-doped lanthanum molybdenum oxide (La₂MoWO₉) ceramic powders were synthesized using the complex polymerization technique. Porous ceramic pellets were obtained by thermally removing graphite, which served as a pore former. The porous pellets were then impregnated with molten eutectic lithium-sodium-potassium carbonates. The energy dispersive X-ray analysis and scanning electron microscopy (FEG-SEM) images of the external and fracture surfaces of the La₂MoWO₉-(Li,Na,K)₂CO₃ composite dual-phase membrane revealed the percolation of the carbonate mixture through the pores. Electrochemical impedance spectroscopy measurements conducted at temperatures below and above the melting point of the eutectic carbonate composition demonstrated the contributions of oxygen and carbonate ions to the ionic conductivity of the dual membrane. The electrical conductivity of the carbonate ions within the membrane was continuously monitored for over 1300 h with negligible degradation, implying that the membrane could be used for long-term monitoring of CO₂ without aging effects. A comparison of FEG-SEM images taken before and after this endurance test suggested minimal fouling, indicating that the membrane could potentially replace similar zirconia- and ceria-based composite membranes.

Keywords: CO2 permeation; LAMOX; ceramic membranes; impedance spectroscopy; scanning electron microscopy.

Grants and funding

This work was supported by Proc. Intercentros 2020.06.IPEN.01, CINE-SHELL (ANP) (FAPESP Proc. 2017/11937-4), CDMF-CEPID (FAPESP Proc. 2013/07296-2), and CNPq (Procs. 402966/2021-0, 302357/2018-1, 305889/2018-4, 305620/2019-3).