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Abstract

In one embodiment, a membrane of proton-electron conducting ceramics that is useful for the conversion of a hydrocarbon and steam to hydrogen has a porous support of M′-Sr_1-z′M″_z′Ce_1-x′-y′Zr_x′M′″_y′O_3-δ, Al₂O₃, mullite, ZrO₂, CeO₂ or any mixtures thereof where: M′ is Ni, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, W, Zn, Pt, Ru, Rh, Pd, alloys thereof or mixtures thereof; M″ is Ba, Ca, Mg, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, or Yb; M′″ is Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, W, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, or Yb; z′ is 0 to about 0.5; x′ is 0 to about 0.5; y′ is 0 to about 0.5; and x′+y′>0; for example, Ni—SrCe_1-x′Zr_x′O_3-δ, where x′ is about 0.1 to about 0.3. The porous support is coated with a film of a Perovskite-type oxide of the formula SrCe_1-x-yZr_xM_yO_3-δ where M is at least one of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, W, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, x is 0 to about 0.15 and y is about 0.1 to about 0.3. By including the Zr and M in the oxide in place of Ce, the stability can be improved while maintaining sufficient hydrogen flux for efficient generation of hydrogen. In this manner, the conversion can be carried out by performing steam methane reforming (SMR) and/or water-gas shift reactions (WGS) at high temperature, where the conversion of CO to CO₂ and H₂ is driven by the removal of H₂ to give high conversions. Methods of preparing the membrane cells and a system for use of the membrane cells to prepare hydrogen are presented. A method for sequestering CO₂ by reaction with methane or other hydrocarbon catalyzed by the novel membrane to form a syngas is also presented.

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First Claim