Method for forming an aluminosilicate-zeolite layer on a metal substrate, the coated substrate and the use thereof

摘要

A method is described for forming an aluminosilicate-zeolite layer on an aluminum-containing substrate by in situ direct crystallization. Aluminum-rich aluminosilicate-zeolite coatings on aluminum-containing metal substrates obtained by this method are advantageous, for example, in sorption-based fields of application, such as heterogeneous catalysis, in separation and cleaning processes, in sorption heat pumps, in conjunction with immobilized catalysts and in microreaction technology.

主权项

1. A method for forming an aluminosilicate-zeolite layer on an aluminium-containing metal substrate comprising the steps of:
transferring the aluminium-containing metal substrate into an aqueous reaction dispersion containing a silicon source and an aluminium source as network-forming elements, wherein, a molar substoichiometric ratio of the aluminium source in the aqueous reaction dispersion to the sum of the silicon source and aluminum source as network-forming elements contained in the aqueous reaction dispersion ranges from 0.02 to about 0.4, heating the aqueous reaction dispersion containing the aluminium-containing metal substrate to thereby extract aluminium from the aluminium-containing metal substrate, and performing in situ direct crystallization to thereby form a layer of an aluminium-rich aluminosilicate-zeolite directly onto the aluminium-containing metal substrate, said layer of an aluminium-rich aluminosilicate-zeolite having an Si/Al ratio of less than 5 wherein the aqueous reaction dispersion contains the silicon source in an amount sufficient for forming the Si/Al ratio of less than 5, and the aluminum source in an amount to satisfy the molar substoichiometric ratio, wherein the pH value of the aqueous reaction dispersion is alkalinized.