| abstract |
The present invention relates to a supported zeolite structure comprising a substantially sintered monolithic porous ceramic substrate coated with a uniformly thin, essentially continuous, zeolite crystal layer covering at least one surface and associating pores of the porous ceramic material. will be. The zeolite crystal layer comprises a single layer or zeolite crystals, there is no growth enhancement layer, selectivity enhancement layer or reparation layer, and exhibits an orientation structure in which the crystal exhibits a substantially cylindrical cross section. Preferably, the porous ceramic substrate support comprises 10-90% by weight of alumina based on analytical oxide, and comprises a crystalline phase assembly selected from the group consisting of cordierite, mullite, alumina, and / or mixtures thereof. It is displayed. The present invention also relates to a method of forming a zeolite membrane. The method generally includes providing a porous ceramic substrate and hydrothermally treating the substrate with an aqueous solution comprising sodium oxide or sodium hydroxide and having an alumina concentration of less than 0.01%. The pH, treatment time and temperature of the solution are essentially continuous zeolite throughout the porous support as these reaction conditions are controlled such that partial dissolution occurs in the alumina of the substrate and essentially no nucleation occurs in the solution. Allow growth. |