US Patent 8435920 Cyclic catalytic upgrading of chemical species using metal oxide materials

Processes are disclosure which comprise alternately contacting an oxygen-carrying catalyst with a reducing substance, or a lower partial pressure of an oxidizing gas, and then with the oxidizing gas or a higher partial pressure of the oxidizing gas, whereby the catalyst is alternately reduced and then regenerated to an oxygenated state. In certain embodiments, the oxygen-carrying catalyst comprises at least one metal oxide-containing material containing a composition having the following formulas: (a) CexByB′zB″Oδ, wherein B=Ba, Sr, Ca, or Zr; B′=Mn, Co, and/or Fe; B″=Cu; 0.01<x<0.99; 0<y<0.6; 0<z<0.5; (b) Ce1-x-yNixByO2-*, wherein B=Zr, Ba, Ca, La, or K; 0.02<x<0.1; 0<y<0.1; and 0.02<*<0.15; and 1<δ<2.2 and (c) coal ash either as a catalyst material itself or as a support for said unary or binary metal oxides.