Ceramic membranes modified with catalytic oxide films as ensembles of catalytic nanoreactors

Hybrid catalytic membrane systems have been produced by modifying porous ceramic membranes with metal oxide films. A two-layer cermet membrane consisting of a flexible stainless steel layer and an overlying porous TiO2 ceramic layer and a ceramic titanium carbide membrane are examined. The membrane surfaces have been modified by the alkoxide method using colloidal organic solutions of metal complex precursors. Producing a tetragonal single-phase ZrO2/Y2O3 coating on the cermet surface increases the abrasion strength of the ceramic layer. CO oxidation and the oxidative conversion of methane into synthesis gas and light hydrocarbons can be markedly intensified by modifying the membrane channels with Cu0.03Ti0.97O2±δ and La + Ce/MgO catalysts, respectively. A method has been developed for depositing, onto the geometrical surface of a membrane, a film of the new single-phase oxide P0.03Ti0.97O2±δ with an anatase structure and uniform pores of mean diameter 〈d〉 ∼ 2 nm. Blocks of zeolite-like silicalite can be formed on the surface of the phosphorus-titanium oxide film. The resulting hybrid membrane is characterized by an anisotropic permeability depending on the flow direction. This property has an effect on conversion and selectivity in the nonoxidative dehydrogenation of methanol.

[1]  A. Domínguez-Rodríguez,et al.  Study of the formation mechanism of complex oxides obtained by the sol–gel method: influence of the structure of iron, aluminium and yttrium acetylacetonate precursors on the phase composition of the ZrO2 ceramics , 1996 .

[2]  Roger B. Poeppel,et al.  Dense ceramic membranes for partial oxidation of methane to syngas , 1995 .

[3]  Sun-Tak Hwang,et al.  Membranes in separations , 1975 .

[4]  R. Dittmeyer,et al.  A Review of Catalytic Membrane Layers for Gas/Liquid Reactions , 2004 .

[5]  F. Sánchez-Bajo,et al.  X-ray microstructural characterization of Y-PSZ (5 mol%) nanocrystalline powder samples , 1998 .

[6]  C. Wert,et al.  Physics of solids , 1964 .

[7]  T. Maschmeyer,et al.  Improvement of zeolite NaA nucleation sites on (0 0 1) rutile by means of UV-radiation , 2003 .

[8]  A. Mosset,et al.  New precursors in the chemistry of IVB transition metal alkoxides. V: Synthesis and molecular structure of Zr3Fe(μ4-O)(μ2-OC3H7)6-(OC3H7)4(acac)3 , 1991 .

[9]  Chusheng Chen,et al.  Conversion of methane to syngas by a membrane-based oxidation-reforming process. , 2003, Angewandte Chemie.

[10]  M. Tsodikov,et al.  Low-temperature formation mechanism of double oxides FexZr(Ti)1−0.75xO2−δ prepared from alkoxides and acetylacetonates , 1995 .

[11]  N. Turova.  The chemistry of metal alkoxides , 2002 .

[12]  You Cong,et al.  Investigation on the partial oxidation of methane to syngas in a tubular Ba0.5Sr0.5Co0.8Fe0.2O3−δ membrane reactor , 2003 .

[13]  N. V. Volbushko,et al.  Photochromic behaviour of non-transition metal chelate complexes of salicylaldimines , 1993 .

[14]  Lev Trusov.  Trumem and Rusmem: New membranes based on ductile ceramics , 2000 .

[15]  D. R. Stull,et al.  The chemical thermodynamics of organic compounds , 1969 .

[16]  A. Domínguez-Rodríguez,et al.  Influence of the Nature of Iron, Aluminium and Yttrium Organometallic Nanocluster Precursors on the Formation Mechanism of Ceramic ZrO2 Obtained by Sol-Gel Method , 1997 .

[17]  K. H. Westmacott,et al.  TEM characterization of indented polycrystalline Y-PSZ , 1993, Journal of Materials Science.

[18]  J. Dalmon,et al.  Catalysis in Membrane Reactors: What About the Catalyst? , 2004 .

[19]  E. V. Slivinskii,et al.  The effect of the structure of Cu-Ti oxide systems obtained by sol-gel synthesis on the nature of catalytic centres and catalytic activity in low-temperature CO oxidation , 1998 .