Molecular sieve layers and processes for their manufacture

Abstract

Layers comprising a molecular sieve layer on a porous or non-porous support, having uniform properties and allowing high flux are prepared from colloidal solutions of zeolite or other molecular sieve precursors (particle size less than 100 nm), by deposition, e.g., by spin or dip-coating, or by in situ crystallization.

1 . A process for catalyzing a chemical reaction which comprises contacting a feedstock with a supported inorganic layer which is in active catalytic form, comprising contiguous particles of a crystalline molecular sieve, the particles having a mean particle size within the range of from 20 nm to 1 μm, and wherein the layer primarily contains nanopores having a size of between 1 and 10 nm, under catalytic conversion conditions and recovering a composition comprising at least one conversion product.  
   
   
       2 . The process of  claim 2 , wherein the supported inorganic layer primarily contains micropores having a size of between 0.2 and 1 nm.  
   
   
       3 . The process of  claim 1 , wherein the particle size distribution of the supported inorganic layer is such that at least 95% of the particles have a size within ±33% of the mean.  
   
   
       4 . The process of  claim 1 , wherein the support is selected from the group consisting of glass, fused quartz, silica, silicon, clay, metal, porous glass, sintered porous metal, titania, and cordierite.  
   
   
       5 . The process of  claim 4 , wherein the supported inorganic layer primarily contains micropores having a size of between 0.2 and 1 nm.  
   
   
       6 . The process of  claim 5 , wherein the particle size distribution of the supported inorganic layer is such that at least 95% of the particles have a size within ±33% of the mean.  
   
   
       7 . A process for catalyzing a chemical reaction which comprises contacting a feedstock with one face of an supported inorganic layer which is in the form of a membrane and is in active catalytic form, comprising contiguous particles of a crystalline molecular sieve, the particles having a mean particle size within the range of from 20 nm to 1 μm, and wherein the layer primarily contains nanopores having a size of between 1 and 10 nm, under catalytic conversion conditions and recovering from an opposite face of the layer at least one conversion product.  
   
   
       8 . The process of  claim 7 , wherein the supported inorganic layer primarily contains micropores having a size of between 0.2 and 1 nm.  
   
   
       9 . The process of  claim 7 , wherein the particle size distribution of the supported inorganic layer is such that at least 95% of the particles have a size within ±33% of the mean.  
   
   
       10 . The process of  claim 7 , wherein the support is selected from the group consisting of glass, fused quartz, silica, silicon, clay, metal, porous glass, sintered porous metal, titania, and cordierite.  
   
   
       11 . The process of  claim 10 , wherein the supported inorganic layer primarily contains micropores having a size of between 0.2 and 1 nm.  
   
   
       12 . The process of  claim 11 , wherein the particle size distribution of the supported inorganic layer is such that at least 95% of the particles have a size within ±33% of the mean.  
   
   
       13 . The process of  claim 7 , wherein the concentration of at least one of the conversion products recovered from the opposite face of the layer is different than the equilibrium concentration of the conversion product in the reaction mixture.  
   
   
       14 . The process of  claim 10 , wherein the concentration of at least one of the conversion products recovered from the opposite face of the layer is different than the equilibrium concentration of the conversion product in the reaction mixture.  
   
   
       15 . The process of  claim 12 , wherein the concentration of at least one of the conversion products recovered from the opposite face of the layer is different than the equilibrium concentration of the conversion product in the reaction mixture.