Materials, Devices and Processes for Energy and Environmental Sustainability
Current Research Group
Research in Progress
Degrees Granted

SOM (Solid-Oxide Oxygen-Ion-Conducting Membrane) Process
for Electrolysis of Metals and Alloys from their Oxides

(Funded by DOE, NSF, and Infinium Inc.)

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Prof. Uday B. Pal

Su Shizhao, Yihong Jiang, Xiaofei Guan, Yiwen Gong and Xiao Han

View a PDF presentation on Magnesium Production From Magnesium Oxide

The research
work demonstrates the technical viability of employing zirconia-based inert SOM anodes for environmentally sound and cost-effective production of metals such as magnesium, tantalum, titanium, rare earths, silicon, aluminum, etc., by directly reducing them from their oxides. The inert anode consists of the oxygen-ion-conducting stabilized zirconia membrane in intimate contact on one side with a catalytically active electronic phase. The opposite (other) side of the zirconia membrane is placed in contact with an ionically conducting solvent phase containing the desired oxide for reduction. A cathode is placed in the solvent and an appropriate electric potential is applied between the electrodes to electrolyze the metals from their oxides.

The full-benefit of the process can be realized if it is conducted at temperatures between 1000-1400C. At these temperatures the ohmic resistance drop across the stabilized zirconia membrane are low and therefore high current densities on the order of 1 A/cm2 or greater can be obtained. In addition, the process efficiency can be further increased by directly reforming hydrocarbon fuel over the anode.

Topics covered in this research include: stability of the zirconia membrane in the selected molten solvent (flux), volatility of the flux, transport processes, potentiodynamic sweeps, electrolysis experiments, metal recovery and analysis and process scaleup.