Selective demetallation of zeolites and related materials
AssigneeExxon Research & Engineering Co.
InventorsDavid E. W. Vaughan, Karl G. Strohmaier
Life of this patent
Estimating the term…
Abstract
A method for demetallating crystalline molecular sieve materials by removing a transition metal in the sieve framework with a complexing agent.
Claims8
A method for demetallating crystalline molecular sieve materials comprising the steps of:
- (a) obtaining a crystalline molecular sieve material having framework cation positions wherein a transition metal is contained in said framework cation positions.
- (b) removing said transition metal from said framework cation positions of said crystalline molecular sieve material by contacting said transition metal containing crystalline molecular sieve material with a complexing agent having a pH above about 3 at a temperature of about 0.degree. to about 300.degree. C. to remove said transition metal from said crystalline molecular sieve material
- (c) annealing said crystalline molecular sieve material having said transition metal removed therefrom wherein said annealing comprises solution phase annealing, vapor phase annealing, thermal annealing, hydrothermal annealing and combinations thereof.
A method according to claim wherein said transition metal containing materials are selected from the group consisting of zeolites, zeolitic materials, metal alumino-phosphates, metal silico-alumino phosphates, metallo silicates, metal-stanno silicates, titano-silicates, zircono-silicates, and mixtures thereof.
A method according to claim I wherein said transition metals of said transition metal containing crystalline material are selected from the elements of the 4th Period of the Periodic Table including V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and mixtures thereof.
Dependencies are inferred from the claim text.