Method for carbon dioxide splitting
A method for splitting carbon dioxide via a two-step metal oxide thermochemical cycle by heating a metal oxide compound selected from an iron oxide material of the general formula A x Fe 3-x O 4 , where 0≦x≦1 and A is a metal selected from Mg, Cu, Zn, Ni, Co, and Mn, or a ceria oxide compound of the general formula M a Ce b O c , where 0<a<1, 0<b<1, and 0<c<2, where M is a metal selected from the group consisting of at least one of a rare earth metal and an alkaline earth metal, to a temperature greater than approximately 1400° C., thereby producing a first solid-gas mixture, adding carbon dioxide, and heating to a temperature less than approximately 1400 C, thereby producing carbon monoxide gas and the original metal oxide compound.
1. A method for splitting carbon dioxide, comprising:
heating a first metal oxide compound to 1400° C. at which the first metal compound reduces, thereby producing a solid-gas mixture comprising a second metal oxide and oxygen;
reacting said second metal oxide with carbon dioxide at 1100° C. at which the second metal oxide oxidizes, thereby producing carbon monoxide gas and the first metal oxide compound; and
separating said carbon monoxide gas;
wherein the first metal oxide compound comprises a metal oxide selected from a group consisting of Co 0.67 Fe 2.33 O 4 /YSZ and Ce 0.25 Zr 0.75 O 2 .
2. The method of claim 1 wherein the step of heating the first metal oxide compound is performed under a partial vacuum to remove produced oxygen.
3. The method of claim 1 wherein a flowing inert gas is used to remove produced oxygen during the step of heating the first metal oxide compound.
4. The method of claim 1 wherein said first metal oxide compound is supported on a monolith.
5. The method of claim 1 wherein said first metal oxide compound is fabricated into a composite monolithic structure.
6. The method of claim 5 wherein said composite monolithic structure comprises a compound selected from the group consisting of zirconia, yttria-stabilized zirconia, hafnia and yttria-doped hafnia.
7. The method of claim 1 wherein said first oxide material is dissolved in a material selected from zirconia or yttria-stabilized zirconia, thereby producing a single crystalline phase material.
8. The method of claim 7 wherein said single crystalline phase material is supported on a monolith.
9. The method of claim 1 wherein heating said first metal oxide compound occurs in the presence of a catalyst.
10. The method of claim 9 wherein said catalyst is selected from Ni, Cr, or a noble metal.
11. The method of claim 1 wherein heating said first metal oxide compound occurs in the presence of a promoter added at a mole fraction of less than 10 mol % of metal content, said promoter selected from Y, La and Ga.
12. The method of claim 1 , wherein said heating is provided using solar energy.