# US 11,993,519 B2 · Layered double hydroxide precursor, their preparation process and catalysts prepared therefrom

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- Number: US 11,993,519 B2
- Document ID: US11993519B2
- Status: Granted
- Kind: B2
- Application number: 16/491,485
- Filed: 2018-03-06
- Published: 2020-01-16
- Granted: 2024-05-28
- Earliest claimed: 2017-03-06
- Assignees: Oxford University Innovation Limited; SCG Chemicals Co., Ltd.
- Applicants: Oxford University Innovation Limited; SCG Chemicals Co., Ltd.
- Inventors: Dermot O'Hare; Shik Chi Tsang; Meng-Jung Li
- Web page: https://patentgrep.com/patent/US11993519B2

## CPC

- C01G 15/006: {Compounds containing gallium, indium or thallium, with or without oxygen or hydrogen, and containing two or more other elements}
- B01J 23/825: with gallium, indium or thallium
- C01G 9/006: {Compounds containing zinc, with or without oxygen or hydrogen, and containing two or more other elements}
- C07C 29/154: containing copper, silver, gold, or compounds thereof
- C01P 2002/22: layered hydroxide-type, e.g. of the hydrotalcite-type
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2002/85: by XPS, EDX or EDAX data
- C01P 2004/04: obtained by TEM, STEM, STM or AFM
- C07C 31/04: Methanol
- Y02P 20/52: using catalysts, e.g. selective catalysts
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

New layered double hydroxide materials useful as intermediates in the formation of catalysts are described, as well as methods of preparing the layered double hydroxides. Also described are catalysts suitable for catalysing the hydrogenation of CO2 to methanol, as well as methods for preparing the catalysts. The LDH-derived catalysts of the invention are active in the hydrogenation of CO2 to methanol, and show improved activity with respect to Cu/ZnO catalysts derived from copper-zinc hydroxycarbonate precursors.

## Claims

### Claim 1

A layered double hydroxide of formula (I) shown below
[M1-xM′x(OH)2]a+(Xn−)a/n·bH2O·c(solvent) (I)
wherein
M represents a mixture of divalent cations comprising Cu2+ and Zn2+;
M′ represents Ga3+, and optionally one or more other trivalent cations selected from Al3+ and Y3+;
0<x≤0.4;
0<b≤10;
0<c≤10;
X represents at least one anion;
n is the charge on anion X and has a value of 1 or 2;
0.2≤a≤0.4; and
the solvent represents at least one organic solvent capable of hydrogen-bonding to water;
wherein a molar ratio of Cu:Zn:Ga within the layered double hydroxide of formula (I) is 1:(0.42-1.00):(0.18-0.65); and
wherein, when the layered double hydroxide is thermally treated at a temperature of 250-400° C. the thermally treated layered double hydroxide is amorphous, optionally containing traces of ZnO phase, and no spinel phase is formed.

### Claim 2 (depends on 1)

The layered double hydroxide of claim 1, wherein M′ is Ga3+.

### Claim 3 (depends on 2)

The layered double hydroxide of claim 2, wherein M represents a mixture of divalent cations comprising Cu2+ and Zn2+, as well as one or more other divalent cations selected from Mg2+, Fe2+, Ca2+, Sn2+, Ni2+, Co2+, Mn2+ and Cd2+.

### Claim 4 (depends on 2)

The layered double hydroxide of claim 2, wherein M represents a mixture of divalent cations consisting of Cu2+ and Zn2+.

### Claim 5 (depends on 4)

The layered double hydroxide of claim 4, wherein X is carbonate.

### Claim 6 (depends on 5)

The layered double hydroxide of claim 5, wherein the solvent is at least one of acetone, acetonitrile and ethanol.

### Claim 7 (depends on 1)

The layered double hydroxide of claim 1, wherein X represents at least one anion selected from a halide, an inorganic oxyanion, and an organic anion.

### Claim 8 (depends on 1)

The layered double hydroxide of claim 1, wherein the solvent is at least one of acetone, acetonitrile, dimethylformamide, dimethyl sulphoxide, dioxane, ethanol, methanol, n-propanol, isopropanol, tetrahydrofuran, ethyl acetate, n-butanol, sec-butanol, n-pentanol, n-hexanol, cyclohexanol, diethyl ether, diisopropyl ether, di-n-butyl ether, methyl tert-butyl ether (MTBE), tert-amyl methyl ether, cyclopentyl methyl ether, cyclohexanone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), methyl isoamyl ketone, methyl n-amyl ketone, furfural, methyl formate, methyl acetate, isopropyl acetate, n-propyl acetate, isobutyl acetate, n-butyl acetate, n-amyl acetate, n-hexyl acetate, methyl amyl acetate, methoxypropyl acetate, 2-ethoxyethyl acetate and nitromethane.

### Claim 9 (depends on 1)

The layered double hydroxide of claim 1, wherein M is Cu2+ and Zn2+ and M′ is Ga3+, and wherein a molar ratio of Cu:Zn:Ga is 1:(0.62-0.72):(0.40-0.50).

### Claim 10 (depends on 1)

A thermally-treated layered double hydroxide, comprising a thermally-treated form of the layered double hydroxide of claim 1.

### Claim 11 (depends on 1, 10)

The thermally-treated layered double hydroxide of claim 10, wherein the thermally-treated layered double hydroxide comprises a calcined form of the layered double hydroxide of claim 1.

### Claim 12 (depends on 10, 11)

A process for preparation of methanol by hydrogenation of carbon dioxide and/or carbon monoxide, the process comprising the step of:
a. providing the thermally-treated layered double hydroxide as claimed in any of claims 10 and 11;
b. reducing the thermally-treated layered double hydroxide provided in step a) to yield a catalyst; and
c. contacting the catalyst obtained in step b) with a mixture of hydrogen and one or both of carbon monoxide and carbon dioxide.

### Claim 13 (depends on 12)

The process of claim 12, wherein step c) comprises contacting the catalyst with a mixture of carbon dioxide and hydrogen.

### Claim 14 (depends on 12)

The process of claim 12, wherein step c) is conducted at a temperature of 200-350° C.

### Claim 15 (depends on 12)

The catalyst of claim 12, wherein the process has a Cu dispersion of >20%, or wherein the catalyst has a Cu loading of 30-40% by weight relative to a total weight of the catalyst.