Noncrystalline mesoporous molecular sieve substance and method for preparing the same
AssigneeYukong Limited
InventorsRyong Ryoo, Ji Man Kim
Life of this patent
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Abstract
Noncrystalline mesoporous molecular sieve substances are prepared using alkyltrimethylammonium halide as a surfactant in combination with water-soluble organic or inorganic salts capable of binding to a monovalent cation. The sieve substances are superior to the M41S series in thermal stability and hydrothermal stability. The sieve substances are structurized in such a manner that channels uniform in diameter are randomly arranged interconnecting with one another in a three-dimensional way so as to allow reactants to readily diffuse therein.
Claims12
A method for preparing a disordered mesoporous molecular sieve substance exhibiting a three-dimensionally disordered channel network and a narrow pore-size distribution having a line width less than 0.5 nm at the medium height in a channel size distribution curve obtained from an adsorption isotherm of nitrogen, comprising the steps of:
- (A) mixing silicate salt and alklytrimethylammonium halide as a surfactant, represented by the following formula I:
- C.sub.n H.sub.2n+1 (CH.sub.3).sub.3 NX I
- wherein n is an integer of 12 to 18 and X is Cl or Br, to prepare a mixed aqueous solution;
- (B) adding in the mixed aqueous solution one or more water-soluble organic salts selected from the group consisting of ethylenediaminetetraacetate tetrasodium salt, adipic acid disodium salt, sodium acetate, 1,3-benzenedisulfonic acid disodium salt and nitrilotriacetic acid sodium salt;
- (C) subjecting the resulting solution to a hydrothermal reaction in such a way that suitable pH and temperature are maintained for a period so as to give precipitates of the molecular sieve substance;
- (D) filtering and drying precipitates of the molecular sieve substances;
- and
- (E) calcining the filtered and dried precipitates.
A method for preparing a disordered mesoporous molecular sieve substance exhibiting a three-dimensionally disordered channel network and a narrow pore-size distribution having a line width less than 0.5 nm at the medium height in a channel size distribution curve obtained from an adsorption isotherm of nitrogen, comprising the steps of:
- (a) mixing silicate salt, one or more salts selected from the group consisting of aluminates, borates and acid salts of 3d transition metals on the periodic table, and alkyltrimethylammonium halide as a surfactant, represented by the following formula I:
- C.sub.n H.sub.2n+1 (CH.sub.3).sub.3 NX I
- wherein n is an integer of 12 to 18 and X is Cl or Br, to prepare a mixed aqueous solution;
- (b) adding in the mixed aqueous solution one or more water-soluble organic salts selected from the group consisting of ethylenediaminetetraacetate tetrasodium salt, adipic acid disodium salt, sodium acetate, 1,3-benzenedisulfonic acid disodium salt and nitrilotriacetic acid sodium salt;
- (c) subjecting the resulting solution to a hydrothermal reaction in such a way that suitable pH and temperature are maintained for a period so as to give precipitates of the molecular sieve substance;
- (d) filtering and drying precipitates of the molecular sieve substances;
- and
- (e) calcining the filtered and dried precipitates.
Dependencies are inferred from the claim text.