Novel proton conducting materials and devices incorporating them

Abstract

Materials for use in proton transport characterized by several formulas are disclosed. Mixed ion and electron conductors may include metals and/or ceramic electron conductors and a proton conducting material. Hydrogen separation membranes may include porous layers and an electolyte layer including a proton conducting material and an electron conductor. Hydrogen separation membranes may be formed by thermal spray techniques. Hydrogen separation membranes may include a catalyst layer. A method of separating hydrogen from a mixed gas stream includes passing the mixed gas through a first porous layer to an electrolyte layer, dissociating protons and electrons, diffusing the protons and electrons through the electrolyte layer, recombining them, and passing molecular hydrogen through a second porous layer.

1 . A material for use in proton transport, comprising a formula A x B y C x O d , wherein: 
 A is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof,    B is selected from Zr, Ce, or Hf, and mixtures thereof;    C is selected from Li, Be, B, C, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Rb, Sr, Y, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ti, Pb, Fr, Ra, La, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, and Lu, and mixtures thereof;    x and y vary according to 
 3.2=x+y=4.8,  
 the subscripts x, y, z and d are adjusted by a common multiplier so that lesser of x and y is 2  
 and x ? y,  
   z varies according to 0=z=0.8; and    d takes a value consistent with the oxidation states of A, B, and C and the stoichiometry x, y, and z to balance the net formula charge, and A and/or C are present in effective amounts for improving proton transport relative to La 2 Zr 2 O 7 .    
     
     
         2 . The material of  claim 1 , wherein B is Ce.  
     
     
         3 . The material of  claim 2 , wherein 
 A is selected from Y, La, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof; and    C is selected from Li, Be, B, C, Na, Si, K, Sc, Zn, Ga, Ge, Rb, Tc, Ag, Cd, Cs, Ba, Ta, Re, Au, Hg, Tl, Fr, Ra, La, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, and Lu, and mixtures thereof.    
     
     
         4 . A material for use in proton transport, comprising a formula A x B y C z O d , wherein 
 A is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof;    B is Zr, Ce, or Hf; or a mixture thereof;    C is a mixture of at least two of Li, Be, B, carbon, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Rb, Sr, Y, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ti, Pb, Fr, Ra, La, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, and Lu;    x and y vary according to 
 3.2=x+y=4.8,  
 the subscripts x, y, z and d are adjusted by a common multiplier so that lesser of x and y is 2, and  
 x ? y;  
   z varies according to 0=z=0.4; and    d takes a value consistent with the oxidation states of A, B, and C and the stoichiometry x, y, and z to balance the net formula charge, and A and/or C are present in effective amounts for improving proton transport relative to La 2 Zr 2 O 7 .    
     
     
         5 . A material for use in proton transport, comprising a formula  
         ABC z O d , wherein  A is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof;    B is Zr, Ce, or Hf or a mixture thereof;    C is selected from Li, Be, B, carbon, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Rb, Sr, Y, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Fr, Ra, La, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, and Lu, and mixtures thereof;    z varies according to 0<z=0.8; and    d takes a value consistent with the oxidation states of A, B, and C and the stoichiometry x, y, and z to balance the net formula charge, and A and/or C are present in effective amounts for improving proton transport relative to La 2 Zr 2 O 7 .    
     
     
         6 . A material for use in proton transport, comprising a formula A x B y C z O d , wherein 
 A is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof;    B is Th, optionally admixed with one or more of Ti, Zr, Ce, or Hf;    C is selected from Groups IA through IVA, Groups IB through VIIIB, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof;    x and y vary according to 3.2=x+y=4.8;    0.75=x/y=1.5;    z varies according to 0=z=0.8; and    d takes a value consistent with the oxidation states of A, B, and C and the stoichiometry x, y, and z to balance the net formula charge, and A and/or C are present in effective amounts for improving proton transport relative to La 2 Zr 2 O 7 .    
     
     
         7 . A material for use in proton transport, comprising a formula A x B y C z O d , wherein 
 A is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof;    B is Ti, optionally admixed with an element selected from the group consisting of Zr, Ce, Hf. Th, and combinations thereof;    C is selected from Li, Ba, Be, B, carbon, Ce Na, Si, K, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Rb, Y, Zr, Nb, Mo, Tc, Rh, Pd, Ag, Cd, Sn, Cs, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ti, Pb, Fr, Ra, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, and Lu, and mixtures thereof;    x and y vary according to 1.6=x+y=2.4 and 0.75=x/y=1.5;    z varies according to 0<z=0.4; and    d takes a value consistent with the oxidation states of A, B, and C and the stoichiometry x, y, and z to balance the net formula charge, and A and/or C are present in effective amounts for improving proton transport relative to La 2 Zr 2 O 7 .    
     
     
         8 . A mixed ion and electron conductor comprising a mixture of a ceramic electron conductor and the material of any of claims  1 - 7 .  
     
     
         9 . A mixed ion and electron conductor comprising a mixture of a metal and the material of any of claims  1 - 7 .  
     
     
         10 . A hydrogen separation membrane comprising a first porous layer, an electrolyte layer, and a second porous layer, the electrolyte layer being composed of the material of any of claims  1 - 7  and an electron conductor.  
     
     
         11 . The hydrogen separation membrane of  claim 10 , wherein the first porous layer comprises a catalyst.  
     
     
         12 . The hydrogen separation membrane of  claim 10 , wherein the first porous layer is a permselective membrane.  
     
     
         13 . The hydrogen separation membrane of  claim 10 , wherein the first porous layer comprises a material capable of transporting protons by lattice interaction with the protons.  
     
     
         14 . A method of separating hydrogen from a mixed gas stream, comprising the steps of 
 passing the mixed gas stream through a first porous layer to a first surface of an electrolyte layer,    dissociating protons and electrons from the mixed gas stream at the first surface of the electrolyte layer,    diffusing protons and electrons through the electrolyte layer,    combining protons and electrons into molecular hydrogen at a second surface of the electrolyte layer, and    passing the molecular hydrogen through a second porous layer.