Method for obtaining metal oxides supported on mesoporous silica particles

Patent metadata

Field	Value
Publication number	US-2022161240-A1
Application number	US-202017609339-A
Country	US
Kind code	A1
Filing date	May 7, 2020
Priority date	May 8, 2019
Publication date	May 26, 2022
Grant date	—

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

1 . A method for obtaining 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 containing Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Ir, Pt and Au, preferably V, Fe, Ni, Cu, Ru, Rh, Pd, Ag and Pt, more preferably V, Ni, Ru, Rh, Pd and Pt; 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 containing halogen, alkoxy, aryloxy, acyloxy, in particular —OH, -alkoxy, and
n is ≥1, in particular ≥2;
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, preferably 8-12, 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, preferably 5; and g) calcination 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, in particular Methoxy, Ethoxy, n-Propoxy or Butoxy, C 6-10 -Aryloxy, in particular Phenoxy, C 2-7 -Acyloxy, in particular Acetoxy or Propionoxy.

3 . The method according to claim 1 , wherein X is hydroxy (OH), amine (—NR 2 2 , where R 2 can be 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 being an alkyl chain), phosphonic acid (—PO 3 H 2 ), sulfide (—S—), phosphine (—PR 4 2 , where R 4 can be H or an alkyl chain), pyridine, 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 or (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, preferably between 1:6 and 1:1, more preferably 1:2, forming a solution with a pH value between 6-12, preferably 8-12.

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 from the group of poly(alkylene oxide)triblock copolymer, in particular HO(CH 2 CH 2 O) 20 (CH 2 CH(CH 3 )O) 70 (CH 2 CH 2 O) 20 H (Pluronic P123).

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, preferably 24 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, preferably between 25 and 35 wt %, in particular preferably between 27 and 30 wt % of SiO 2 , and 5-30 wt %, preferably 10-20 wt %, most preferably 10-15 wt % of NaOH.

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, preferably 5 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, preferably 24 h at a temperature between 20° C. and 100° C., preferably between 20° C. and 60° C., more preferably between 20° C. and 50° C., most preferably between 20° C. and 30° 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 400 and 800° C., preferably between 500 and 700° C. for 2-12 h, preferably 5-8 h, more preferably 6-7 h.

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

• B01J37/082

  Decomposition and pyrolysis · CPC title

• B01J2229/18

  to introduce other elements into or onto the molecular sieve itself · CPC title

• B01J37/04

  Mixing {(B01J37/0009, B01J37/0018 take precedence)} · CPC title