Method for obtaining metal oxides supported on mesoporous silica particles

Patent metadata

Field	Value
Publication number	US-12290798-B2
Application number	US-202017609339-A
Country	US
Kind code	B2
Filing date	May 7, 2020
Priority date	May 8, 2019
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

A method for obtaining metal oxides supported on mesoporous silica particles includes a) providing a solution of at least one metal salt, b) providing a solution of at least one template forming agent of the general formula (I) Y 3 Si(CH 2 ) n —X (I), wherein X is a complexing functional group; Y is —OH or a hydrolysable moiety selected from the group containing halogen, alkoxy, aryloxy, acyloxy, c) mixing the metal salt solution and the complex forming agent solution to obtain a metal precursor; d) adding at least one solution containing at least one pore structure directing agent to the metal precursor to obtain a metal precursor template mixture; e) adding at least one alkali silicate solution to the metal precursor template mixture at room temperature to obtain a silica-supported metal complex; and f) calcination of the silica-supported metal complex under air to obtain the supported metal oxide mesoporous silica particles.

First claim

The invention claimed is:

1. A method for preparing metal oxides supported on mesoporous silica particles comprising the steps of:
a) providing a solution of at least one metal salt, wherein the metal is selected from a group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Ir, Pt and Au;
b) providing a solution of at least one complex forming agent, wherein the at least one complex forming agent is of the general formulae (I)
Y 3 Si(CH 2 ) n —X  (I)

wherein:
X is a complexing functional group,
Y is —OH or a hydrolysable moiety selected from the group consisting of halogen, alkoxy, aryloxy, and acyloxy, and
n is ≥1;

c) mixing the metal salt solution of step a) and the complex forming agent solution of step b) to obtain a metal precursor solution with a pH value between 6-12, which functional group/metal ratio is ≥1;
d) adding a buffered solution containing at least one pore structure directing agent (SDA) (or template) adjusted to a pH range between 2 and 8;
e) mixing the metal precursor solution of step c) and the buffered template solution of step d) to obtain a buffered metal precursor-template-mixture;
f) adding at least one alkali silicate solution to the metal precursor-template
mixture of step d) at room temperature to obtain a silica-supported metal complex, at a pH adjusted to a range between 4 and 8; and
g) calcining of the silica-supported metal complex of step f) under air to obtain the supported metal oxide mesoporous silica particles.

2. The method according to claim 1 , wherein Y is —OH, C 1-6 -Alkoxy, C 6-10 -Aryloxy, or C 2-7 -Acyloxy.

3. The method according to claim 1 , wherein X is hydroxy (OH), amine (—NR 2 2 , where R 2 is H or an alkyl chain), imino, urea (—NH)CO(NH 2 )), amide (—CONH 2 )), carboxylic acid (—CO 2 H), carboxylic acid anion (—CO 2 ), sulfonic acid (—SO 3 H), sulfonic acid anion (—SO 3 ), methanethionic acid (—CS 2 H), phosphonate (—PO 3 R 3 2 with R 3 is an alkyl chain), phosphonic acid (—PO 3 H 2 ), sulfide (—S—), phosphine (—PR 4 2 , where R 4 is H or an alkyl chain), pyridine, or pyrazine.

4. The method according to claim 1 , wherein the at least one complex forming agent of general formulae (i) is selected from a group comprising Carboxyethylsilanetriol sodium salt, (3-Aminopropyl)trimethoxysilane, N1-(3-Trimethoxysilylpropyl)diethylenetriamine, N-(2-Aminoethyl)-3-aminopropylsilanetriol, 3-Aminopropylsilanetriol, (N,N-Dimethylaminopropyl)trimethoxysilane, 1-[3-(Trimethoxysilyl)propyl]urea, N-[3-(Trimethoxysilyl)propyl]ethylenediamine, 3-[Bis(2-hydroxyethyl) amino]propyl-triethoxysilane, N-(Trimethoxysilylpropyl)-ethylenediaminetriacetate, tripotassium salt, N-(Trimethoxysilylpropyl) ethylene-diaminetriacetate, tripotassium salt, 3-(Trihydroxysilyl)-1-propanesulfonic acid, (2-diethylphosphatoethyl) triethoxysilane, 3-(trihydroxysilyl)propyl methylphosphonate, Bis[3-(triethoxysilyl) propyl]tetrasulfide, Bis[3-(triethoxysilyl)propyl]disulphide, (2-Dicyclohexylphosphinoethyl) triethoxysilane, 2-(Diphenylphosphino)ethyl-triethoxysilane, 2-(4-pyridylethyl) triethoxysilane, 3-(4-pyridylethyl)thiopropyltrimethoxysilane and (3-Bromopropyl)trimethoxysilane.

5. The method according to claim 1 , wherein the metal salt and the complex forming agent are mixed in a ratio ≥1.

6. The method according to claim 1 , wherein the at least one pore structure directing agent (SDA) or template is a non-ionic polymeric pore structure directing agent.

7. The method according to claim 1 , wherein the SDA or template is dissolved in a buffered solution adjusted to a pH range between 2 and 8.

8. The method according to claim 1 , wherein the metal precursor-template-mixture obtained in step d) is stirred at room temperature for 12-36 h.

9. The method according to claim 1 , wherein the at least one alkali silica solution comprises an aqueous sodium silicate solution.

10. The method according to claim 1 , wherein the at least one alkali silica solution comprises the alkali silicate in an amount between 20 and 40 wt % based on the total solution.

11. The method according to claim 1 , wherein in step f) the pH of the mixture is adjusted to a range between 4 and 8 in a buffered system.

12. The method according to claim 1 , wherein the buffer system is composed of acetic acid/sodium acetate, sodium citrate/citric acid, Na 2 HPO 4 /citric acid, HCl/sodium citrate or Na 2 HPO/NaH 2 PO 4 .

13. The method according to claim 1 , wherein the silica-supported metal complex obtained in step f) is allowed to age for 12 to 48 h at a temperature between 20° C. and 100° C.

14. The method according to claim 1 , wherein the calcination of the supported metal silica complex in step g) is carried out at a temperature between 40° and 800° C. for 2-12 h.

15. The method according to claim 1 , wherein the metal oxide is used as affinity material for enzyme purification, enzyme immobilization, or catalyst.

Assignees

• Univ Berlin Tech

Inventors

• Colmenares Maria
• Harris Tomos
• Sialelli Julien
• Silva Mora Javier
• Thomas Arne

Classifications

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• C01B39/06

  Preparation of isomorphous zeolites characterised by measures to replace the aluminium or silicon atoms in the lattice framework by atoms of other elements {, i.e. by direct or secondary synthesis} · CPC title

• C01B39/02

  Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof · CPC title

• C01B39/08

  the aluminium atoms being wholly replaced · CPC title