Catalyst for isobutanol synthesis

Abstract

M / M2 + M4 + oxide catalysts have been developed for the production of isobutanol in propanol-methanol, ethanol-methanol, and propanol / ethanol mixture-methanol reactions. The catalyst can also be used for preparing n-butyl alcohol in an ethanol-ethanol reaction. M may include one or more metals from Groups 3-12 of the Periodic Table. M < 2 + > may include divalent magnesium, calcium, strontium, barium, or a combination thereof. M4 + may include tetravalent silicon, titanium, zirconium, or a combination thereof. Catalysts and methods of using the catalysts are described.

Description

BACKGROUND OF THE INVENTION

[0001] Isobutanol is an organic solvent and raw material for the preparation of isobutyl acetate and isobutyl esters. It can also be directly mixed with gasoline to increase the octane number and combustion efficiency, or used alone as an alternative fuel. Compared with ethanol, isobutanol has a relatively high energy density and low volatility. In addition, it does not easily absorb water from the air, preventing or reducing corrosion of engines and pipelines. Despite its many potential uses, its synthesis is limited. Isobutanol is currently produced by the carbonylation of propylene. This method involves reacting propylene with carbon monoxide and hydrogen to produce butyraldehyde and isobutyraldehyde, hydrogenating them to n-butanol and isobutanol, and subsequently separating the butanols. A new alternative technology is biomass fermentation. However, in both of these homogeneous methods, the selectivity of isobutanol is low and the productivity is limited, resulting in a high cost of isobutanol.

[0002] The Guerbet reaction is an alternative method for synthesizing isobutanol from methanol and ethanol / propyl alcohol. This reaction is particularly important because it can prepare value-added isobutanol from low-cost mixed alcohols. The Guerbet reaction proceeds by a coupling method between alcohols on a multifunctional catalyst having dehydrogenation activity, strong surface basicity, weak acidity, and hydrogenation activity. The reaction is as follows:

[0003] C2H5OH + CH3OH = C3H7OH + H2O (1)

[0004] C3H7OH + CH3OH = C4H9OH + H2O (2)

[0005] C2H5OH + 2CH3OH = C4H9OH + 2H2O (3)

[0006] Therefore, various catalysts and methods for preparing isobutanol from methanol, ethanol, and propyl alcohol have been sought. For example, U.S. Patent Nos. 5,581,602, 5,707,920, 5,770,541, 5,908,807, 5,939,352, and 6,034,141 describe noble metal-loaded alkali metal-doped ZnMnZr oxide catalysts for converting methanol and ethanol or methanol, ethanol, and propyl alcohol to isobutanol.

[0007] US 5,559,275 discloses a method for converting methanol, ethanol, and propyl alcohol to higher branched oxygenates such as isobutanol on a catalyst comprising a) a mixed oxide support having at least two components selected from oxides of Zn, Mg, Zr, Mn, Ti, Cr, and La; and b) an active metal selected from Pd, Pt, Ag, Rh, Co, and mixtures thereof.

[0008] Carlini, “Guerbet condensation of methanol with n - propanol to isobutylalcohol over heterogeneous bifunctional catalysts based on Mg - Al mixed oxides partially substituted by different metal components,” Journal of Molecular Catalysis A: Chemical, 2005, 232, 13 described Mg - Al mixed oxides doped with Pd, Rh, Ni, and Cu for the synthesis of isobutyl alcohol from methanol and propanol.

[0009] US20190031585 discloses a method for converting ethanol to higher alcohols (such as n - butanol) over a Cu - MgO - Al2O3 catalyst having less than 0.25 wt% Cu. The Cu is pseudo - single - atom and is small and highly dispersed on the support.

[0010] , “Review of catalytic systems and thermodynamics for the Guerbet condensation reaction and challenges for biomass valorization,” Catalysis Science & Technology, 2015, 5, 3876 summarized a series of catalysts for the reaction between methanol and ethanol / propanol, including alkali or alkaline earth metals supported on Al2O3, Ca or Sr hydroxyapatite, hydrotalcite, MgO, Mg(OH)2, Rb - Li exchanged zeolite X, and Na2CO3 / NaX.

[0011] There is still a need for catalysts for producing isobutyl alcohol from methanol, ethanol, and propanol, as well as methods for preparing and using such catalysts. Detailed Description

[0012] M / M 2+ M 4+ oxide catalysts have been developed, which show good isobutyl alcohol yields in the propanol - methanol, ethanol - methanol, and propanol / ethanol mixture - methanol reactions. They also show good n - butanol yields in the ethanol - ethanol reaction. Methanol and ethanol can react to form propanol, and then M / M 2+ M 4+The oxide catalyst causes the propanol to react with methanol to form isobutanol. Alternatively, M / M can be used 2+ M 4+ The oxide catalyst causes methanol to react directly with propanol to produce isobutanol. A mixture of propanol and ethanol can react with methanol. Ethanol can also react with ethanol to form n-butanol.

[0013] One aspect of the present invention is an alcohol condensation catalyst for isobutanol synthesis. In one embodiment, the catalyst comprises M / M 2+ M 4+ oxide catalyst. M can include one or more metals from Groups 3-12 of the periodic table. M 2+ can include divalent magnesium, calcium, strontium, barium, or combinations thereof. M 2+ can consist essentially of divalent magnesium, calcium, strontium, barium, or combinations thereof. M 2+ can be selected from divalent magnesium, calcium, strontium, barium, or combinations thereof. M 4+ can include tetravalent silicon, titanium, zirconium, or combinations thereof. M 4+ can consist essentially of tetravalent silicon, titanium, zirconium, or combinations thereof. M 4+ can be selected from tetravalent silicon, titanium, zirconium, or combinations thereof.

[0014] In some embodiments, M includes Cu, Co, Fe, Ni, Ru, Rh, Pd, Ir, Pt, Ag, Au, or combinations thereof. In some embodiments, M is Cu.

[0015] In some embodiments, the amount of M present in the catalyst is from 0.01 wt% to 50 wt%, or from 0.01 wt% to 40 wt%, or from 0.01 wt% to 30 wt%, or from 0.01 wt% to 25 wt%, or from 0.01 wt% to 20 wt%, or from 0.01 wt% to 15 wt%, or from 0.01 wt% to 10 wt%, or from 0.1 wt% to 50 wt%, or from 0.1 wt% to 40 wt%, or from 0.1 wt% to 30 wt%, or from 0.1 wt% to 25 wt%, or from 0.1 wt% to 20 wt%, or from 0.1 wt% to 15 wt%, or from 0.1 wt% to 10 wt%, or from 0.5 wt% to 50 wt%, or from 0.5 wt% to 40 wt%, or from 0.5 wt% to 30 wt%, or from 0.5 wt% to 25 wt%, or from 0.5 wt% to 20 wt%, or from 0.5 wt% to 15 wt%, or from 0.5 wt% to 10 wt%, or from 1 wt% to 50 wt%, or from 1 wt% to 40 wt%, or from 1 wt% to 30 wt%, or from 1 wt% to 25 wt%, or from 1 wt% to 20 wt%, or from 1 wt% to 15 wt%, or from 1 wt% to 10 wt%, or from 2 wt% to 50 wt%, or from 2 wt% to 40 wt%, or from 2 wt% to 30 wt%, or from 2 wt% to 25 wt%, or from 2 wt% to 20 wt%, or from 2 wt% to 15 wt%, or from 2 wt% to 10 wt%, or from 5 wt% to 50 wt%, or from 5 wt% to 40 wt%, or from 5 wt% to 30 wt%, or from 5 wt% to 25 wt%, or from 5 wt% to 20 wt%, or from 5 wt% to 15 wt%, or from 5 wt% to 10 wt%, or from 10 wt% to 50 wt%, or from 10 wt% to 40 wt%, or from 10 wt% to 30 wt%, or from 10 wt% to 25 wt%, or from 10 wt% to 20 wt%, or from 10 wt% to 15 wt%, or from 15 wt% to 50 wt%, or from 15 wt% to 40 wt%, or from 15 wt% to 30 wt%, or from 15 wt% to 25 wt%, or from 15 wt% to 20 wt%, or from 20 wt% to 50 wt%, or from 20 wt% to 40 wt%, or from 20 wt% to 30 wt%, or from 20 wt% to 25 wt%, or from 25 wt% to 50 wt%, or from 25 wt% to 40 wt%, or from 25 wt% to 30 wt%, or from 30 wt% to 50 wt%, or from 30 wt% to 40 wt%, or from 35 wt% to 50 wt%, or from 35 wt% to 40 wt%, or from 40 wt% to 50 wt%.

[0016] In some embodiments, M 2+The content of O in the catalyst is 1 wt% to 50 wt%, or 1 wt% to 75 wt%, or 1 wt% to 70 wt%, or 1 wt% to 65 wt%, or 1 wt% to 60 wt%, or 2 wt% to 98 wt%, or 2 wt% to 75 wt%, or 2 wt% to 70 wt%, or 2 wt% to 65 wt%, or 2 wt% to 60 wt%, or 5 wt% to 98 wt%, or 5 wt% to 75 wt%, or 5 wt% to 70 wt%, or 5 wt% to 65 wt%, or 5 wt% to 60 wt%, or 10 wt% to 98 wt%, or 10 wt% to 75 wt%, or 10 wt% to 70 wt%, or 10 wt% to 65 wt%, or 10 wt% to 60 wt%, or 15 wt% to 98 wt%, or 15 wt% to 75 wt%, or 15 wt% to 70 wt%, or 15 wt% to 65 wt%, or 15 wt% to 60 wt%, or 20 wt% to 98 wt%, or 20 wt% to 75 wt%, or 20 wt% to 70 wt%, or 20 wt% to 65 wt%, or 20 wt% to 60 wt%, or 25 wt% to 98 wt%, or 25 wt% to 75 wt%, or 25 wt% to 70 wt%, or 25 wt% to 65 wt%, or 25 wt% to 60 wt%, or 30 wt% to 98 wt%, or 30 wt% to 75 wt%, or 30 wt% to 70 wt%, or 30 wt% to 65 wt%, or 30 wt% to 60 wt%, or 35 wt% to 98 wt%, or 35 wt% to 75 wt%, or 35 wt% to 70 wt%, or 35 wt% to 65 wt%, or 35 wt% to 60 wt%, or 40 wt% to 98 wt%, or 40 wt% to 75 wt%, or 40 wt% to 70 wt%, or 40 wt% to 65 wt%, or 40 wt% to 60 wt%, or 45 wt% to 98 wt%, or 45 wt% to 75 wt%, or 45 wt% to 70 wt%, or 45 wt% to 65 wt%, or 45 wt% to 60 wt%, or 50 wt% to 98 wt%, or 50 wt% to 75 wt%, or 50 wt% to 70 wt%, or 50 wt% to 65 wt%, or 50 wt% to 60 wt%, or 55 wt% to 98 wt%, or 55 wt% to 75 wt%, or 55 wt% to 70 wt%, or 55 wt% to 65 wt%, or 55 wt% to 60 wt%, 5 wt% to 98 wt%, or 5 wt% to 75 wt%, or 5 wt% to 70 wt%, or 5 wt% to 65 wt%, or 5 wt% to 60 wt%, or 10 wt% to 98 wt%, or 10 wt% to 75 wt%, or 10 wt% to 70 wt%, or 10 wt% to 65 wt%, or 10 wt% to 60 wt%, or 15 wt% to 98 wt%, or 15 wt% to 75 wt%or 15 wt% to 70 wt%, or 15 wt% to 65 wt%, or 15 wt% to 60 wt%, or 20 wt% to 98 wt%, or 20 wt% to 75 wt%, or 20 wt% to 70 wt%, or 20 wt% to 65 wt%, or 20 wt% to 60 wt%, or 25 wt% to 98 wt%, or 25 wt% to 75 wt%, or 25 wt% to 70 wt%, or 25 wt% to 65 wt%, or 25 wt% to 60 wt%, or 30 wt% to 98 wt%, or 30 wt% to 75 wt%, or 30 wt% to 70 wt%, or 30 wt% to 65 wt%, or 30 wt% to 60 wt%, or 35 wt% to 98 wt%, or 35 wt% to 75 wt%, or 35 wt% to 70 wt%, or 35 wt% to 65 wt%, or 35 wt% to 60 wt%, or 40 wt% to 98 wt%, or 40 wt% to 75 wt%, or 40 wt% to 70 wt%, or 40 wt% to 65 wt%, or 40 wt% to 60 wt%, or 45 wt% to 98 wt%, or 45 wt% to 75 wt%, or 45 wt% to 70 wt%, or 45 wt% to 65 wt%, or 45 wt% to 60 wt%, or 50 wt% to 98 wt%, or 50 wt% to 75 wt%, or 50 wt% to 70 wt%, or 50 wt% to 65 wt%, or 50 wt% to 60 wt%, or 55 wt% to 98 wt%, or 55 wt% to 75 wt%, or 55 wt% to 70 wt%, or 55 wt% to 65 wt%, or 55 wt% to 60 wt%.

[0017] In some embodiments, M 4+The amount of O2 present in the catalyst is: 1 wt% to 98 wt%, or 1 wt% to 75 wt%, or 1 wt% to 70 wt%, or 1 wt% to 65 wt%, or 1 wt% to 60 wt%, or 2 wt% to 98 wt%, or 2 wt% to 75 wt%, or 2 wt% to 70 wt%, or 2 wt% to 65 wt%, or 2 wt% to 60 wt%, or 5 wt% to 98 wt%, or 5 wt% to 75 wt%, or 5 wt% to 70 wt%, or 5 wt% to 65 wt%, or 5 wt% to 60 wt%, or 10 wt% to 98 wt%, or 10 wt% to 75 wt%, or 10 wt% to 70 wt%, or 10 wt% to 65 wt%, or 10 wt% to 60 wt%, or 15 wt% to 98 wt%, or 15 wt% to 75 wt%, or 15 wt% to 70 wt%, or 15 wt% to 65 wt%, or 15 wt% to 60 wt%, or 20 wt% to 98 wt%, or 20 wt% to 75 wt%, or 20 wt% to 70 wt%, or 20 wt% to 65 wt%, or 20 wt% to 60 wt%, or 25 wt% to 98 wt%, or 25 wt% to 75 wt%, or 25 wt% to 70 wt%, or 25 wt% to 65 wt%, or 25 wt% to 60 wt%, or 30 wt% to 98 wt%, or 30 wt% to 75 wt%, or 30 wt% to 70 wt%, or 30 wt% to 65 wt%, or 30 wt% to 60 wt%, or 35 wt% to 98 wt%, or 35 wt% to 75 wt%, or 35 wt% to 70 wt%, or 35 wt% to 65 wt%, or 35 wt% to 60 wt%, or 40 wt% to 98 wt%, or 40 wt% to 75 wt%, or 40 wt% to 70 wt%, or 40 wt% to 65 wt%, or 40 wt% to 60 wt%, or 45 wt% to 98 wt%, or 45 wt% to 75 wt%, or 45 wt% to 70 wt%, or 45 wt% to 65 wt%, or 45 wt% to 60 wt%, or 50 wt% to 98 wt%, or 50 wt% to 75 wt%, or 50 wt% to 70 wt%, or 50 wt% to 65 wt%, or 50 wt% to 60 wt%, or 55 wt% to 98 wt%, or 55 wt% to 75 wt%, or 55 wt% to 70 wt%, or 55 wt% to 65 wt%, or 55 wt% to 60 wt%.

[0018] In some embodiments, M 2+ contains divalent magnesium.

[0019] In some embodiments, M 4+ contains silicon.

[0020] In some embodiments, the catalyst further comprises a salt or oxide of a Group 1 metal of the periodic table, or a combination thereof. In some embodiments, the Group 1 metal includes Li, Na, K, Rb, Cs, or a combination thereof. The Group 1 metal may be present in an amount of: 0.01 wt% to 10 wt%, or 0.05 wt% to 10 wt%, or 0.1 wt% to 10 wt%, or 0.5 wt% to 10 wt%, or 1 wt% to 10 wt%, or 2 wt% to 10 wt%, or 3 wt% to 10 wt%, or 4 wt% to 10 wt%, or 5 wt% to 10 wt%, or 6 wt% to 10 wt%, or 7 wt% to 10 wt%, or 8 wt% to 10 wt%, or 9 wt% to 10 wt%, or 0.01 wt% to 8 wt%, or 0.01 wt% to 5 wt%, or 0.01 wt% to 2 wt%, or 0.01 wt% to 1 wt%, or 0.01 wt% to 0.5 wt%, or 0.05 wt% to 8 wt%, or 0.05 wt% to 5 wt%, or 0.05 wt% to 2 wt%, or 0.05 wt% to 1 wt%, or 0.05 wt% to 0.5 wt%, or 0.1 wt% to 8 wt%, or 0.1 wt% to 5 wt%, or 0.1 wt% to 2 wt%, or 0.1 wt% to 1 wt%, or 0.1 wt% to 0.5 wt%, or 0.5 wt% to 8 wt%, or 0.5 wt% to 5 wt%, or 0.5 wt% to 2 wt%, or 0.5 wt% to 1 wt%, or 1 wt% to 8 wt%, or 1 wt% to 5 wt%, or 1 wt% to 2 wt%, or 2 wt% to 8 wt%, or 2 wt% to 5 wt%, or 3 wt% to 5 wt%, or 4 wt% to 8 wt%, or 4 wt% to 5 wt%.

[0021] Another aspect of the present invention is a method for producing isobutanol or n-butanol. In one embodiment, the method comprises: reacting ethanol or propanol with methanol in the presence of an alcohol condensation catalyst under reaction conditions to produce isobutanol, or reacting ethanol with ethanol in the presence of an alcohol condensation catalyst under reaction conditions to produce n-butanol; wherein the alcohol condensation catalyst comprises M / M 2+ M 4+ oxide catalyst; wherein M comprises a metal from Group 3-12 of the periodic table or a combination thereof; wherein M 2+ comprises divalent magnesium, calcium, strontium, barium, or a combination thereof; wherein M 4+ comprises tetravalent silicon, titanium, zirconium, or a combination thereof.

[0022] M / M 2+ M 4+ oxide catalyst as described above.

[0023] In some embodiments, the reaction conditions include one or more of the following: a temperature of 100 °C to 500 °C; or a pressure of 5 kPa to 30,000 kPa.

[0024] Using M / M 2+ M 4+ The method for preparing isobutanol or n-butanol using an oxide catalyst allows for good conversion of methanol, ethanol, or propanol, as well as good selectivity and productivity of isobutanol or n-butanol.

[0025] Examples

[0026] Example 1

[0027] Mg2SiO4 was prepared by reacting Mg(NO3)2·6H2O (dissolved in ethanol) with an aqueous solution of Na2SiO3·9H2O in an autoclave at 170 °C for 24 hours, followed by filtration, washing, drying, and calcination at 450 °C for 4 hours. Cu was impregnated on the surface of Mg2SiO4 by incipient wetness impregnation. The 5% Cu / Mg2SiO4 catalyst thus prepared had a BET surface area of 203 m 2 / g and a pore volume of 0.21 cm 3 / g.

[0028] In a microreactor, the catalyst performance test was carried out at 289 - 337 °C, 600 psi, 11.4% propanol, 22.8% methanol, balance N2, and a GHSV of 3000 ml / g-h. The test results are summarized in Table 1. Under the test conditions, the methanol conversion was 28 - 42%, the propanol conversion was 43 - 66%, the isobutanol selectivity was 30 - 46%, and the isobutanol productivity was 154 - 361 g / kg-h.

[0029] The above results indicate that the Cu-doped Mg2SiO4 catalyst is a good catalyst for converting propanol and methanol to isobutanol via the Guerbet reaction.

[0030] Example 2

[0031] Cu 0.19 Ca 1.81 The CuCaZrO4 catalyst was prepared by a conventional co-precipitation method.

[0032] 3.65 g of Cu(NO3)2·2.5H2O, 36.05 g of Ca(NO3)2·4H2O, and 31.41 g of ZrO(NO3)2·xH2O were dissolved in 167 g of deionized water in a beaker.

[0033] In a separate beaker, dissolve 52.39 g of K2CO3 in 188 g of deionized water.

[0034] With stirring, pump the two solutions into a third beaker containing 200 g of deionized water at 70 °C. The pH of the mixture is maintained at 7.0. After the coprecipitation process is complete, stir the mixture for an additional hour.

[0035] Subsequently, filter the slurry and wash it three times with deionized water. Dry the resulting paste at 120 °C for 12 hours and calcine it at 600 °C for 4 hours.

[0036] Load 1.00 g of the sample into a catalyst bag and place it in a stainless steel autoclave together with 29 g of the solution in a molar ratio of 2:1 CH3OH - C3H7OH. Seal the autoclave, charge it with 2200 psi of ultra-high purity N2, and vent it after two hours to obtain a sealed system with an N2 headspace. Heat the autoclave to 325 °C at a heating rate of 2 °C / minute with stirring and hold it at 325 °C for 15 hours before cooling to room temperature. Record the weights of the liquid, the catalyst bag, and the autoclave. Analyze the liquid by GC to provide information on the conversion of methanol and propanol and the productivity of isobutanol. A methanol conversion of 55%, a propanol conversion of 46%, an isobutanol selectivity of 28%, and an isobutanol productivity of 148 g / kg-h were achieved.

[0037] Example 3

[0038] Prepare 5% Cu / Mg3Si4O by precipitation followed by impregnation 11 . In a 500 ml Nalgene bottle, dissolve 25.6 g of Mg(NO3)2·6H2O and 3.81 g of acetic acid in 50 ml of deionized water. Dissolve 37.9 g of Na2SiO3·9H2O in 300 ml of deionized water and then quickly add it to the Mg(NO3)2 solution with stirring. Stir the mixture vigorously for 30 minutes and then seal it and let it stand at room temperature for four days. Then filter the slurry, wash it with deionized water, and dry it at 120 °C. Mix the dried solid with 100 ml of H2O in a 200 ml Teflon-lined autoclave and heat it at 200 °C for 24 hours. Filter the solid, wash it with 500 ml of H2O, dry it, and calcine it at 500 °C for 4 hours.

[0039] Impregnate 8 g of the calcined material (Mg3Si4O 11 ) with a solution of 0.541 g of Cu(NO3)2·2.5H2O in 2.8 ml of H2O and calcine the material at 400 °C for 8 hours.

[0040] 1.00 g of the sample was loaded into a catalyst bag and placed in a stainless-steel autoclave together with 29 g of the solution in a molar ratio of 2:1 CH3OH - C3H7OH. The autoclave was sealed, charged with 2200 psi of ultra-high purity N2, and vented after two hours to obtain a sealed system with an N2 headspace. The autoclave was heated to 325 °C at a heating rate of 2 °C / min under stirring and held at 325 °C for 15 hours before cooling to room temperature. The weights of the liquid, catalyst bag, and autoclave were recorded. The liquid was analyzed by GC to provide information on the conversion of methanol and propanol and the productivity of isobutanol. A methanol conversion of 55%, a propanol conversion of 60%, an isobutanol selectivity of 30%, and an isobutanol productivity of 206 g / kg-h were achieved.

[0041] Example 4

[0042] 1.0 g of 5% Cu / Mg3Si4O from Example 3 11 was loaded into a catalyst bag and placed in a stainless-steel autoclave together with 31.3 g of an ethanol solution. The autoclave was sealed, charged with 2200 psi of ultra-high purity N2, and vented after two hours to obtain a sealed system with an N2 headspace. The autoclave was heated to 325 °C at a heating rate of 2 °C / min under stirring and held at 325 °C for 15 hours before cooling to room temperature. The weights of the liquid, catalyst bag, and autoclave were recorded. The liquid was analyzed by GC to provide information on the conversion of ethanol and the productivity of n-butanol. An ethanol conversion of 72%, an n-butanol selectivity of 22%, and an n-butanol productivity of 263 g / kg-h were achieved.

[0043] Table 1. Synthesis of isobutanol from propanol - methanol reaction over the catalyst of Example 1

[0044]

[0045] Although at least one exemplary embodiment has been presented in the foregoing detailed description of the present invention, it should be understood that there are numerous variations. It should also be understood that one or more exemplary embodiments are merely examples and are not intended to limit in any way the scope, application, or configuration of the present invention. On the contrary, the foregoing detailed description will provide those skilled in the art with a convenient roadmap for implementing the exemplary embodiments of the present invention. It should be understood that various changes can be made to the functions and arrangements of the elements described in the exemplary embodiments without departing from the scope of the present invention as set forth in the appended claims.

Claims

1. An alcohol condensation catalyst for synthesizing isobutanol, comprising: M / M 2+ M 4+ Oxide catalysts; wherein M comprises a metal of Groups 3-12 of the Periodic Table or a combination thereof; wherein M 2+ includes divalent magnesium, calcium, strontium, barium, or a combination thereof; and Wherein M 4+ comprises tetravalent silicon, titanium, zirconium or a combination thereof; The condition is that when M 2+ is magnesium, M 4+ is not titanium or zirconium.

2. The catalyst according to claim 1, wherein M comprises Cu, Co, Fe, Ni, Ru, Rh, Pd, Ir, Pt, Ag, Au or a combination thereof.

3. The catalyst according to any one of claims 1-2, wherein M comprises Cu.

4. The catalyst according to any one of claims 1-3, wherein M is present in an amount of 0.01 wt% to 50 wt%.

5. The catalyst according to any one of claims 1-4, wherein M 2+ comprises divalent magnesium.

6. The catalyst according to any one of claims 1-5, wherein M 2+ O is present in an amount of 1 wt% to 98 wt%.

7. The catalyst according to any one of claims 1 to 6, wherein M 4+ comprises silicon.

8. The catalyst according to any one of claims 1 to 7, wherein M 4+ O2 is present in an amount of 1% to 98% by weight.

9. The catalyst according to any one of claims 1 to 8, further comprising: a salt or oxide of a Group 1 metal of the Periodic Table, or a combination thereof.

10. The catalyst according to claim 9, wherein the Group 1 metal comprises Li, Na, K, Rb, Cs or a combination thereof.

11. The catalyst according to claim 9, wherein the Group 1 metal is present in an amount of 0.01 wt% to 10 wt%.

12. A method for producing isobutanol, comprising: reacting ethanol or propanol with methanol under reaction conditions in the presence of an alcohol condensation catalyst to prepare isobutanol; wherein the alcohol condensation catalyst comprises M / M 2+ M 4+ oxide catalyst; wherein M comprises a metal of Groups 3-12 of the Periodic Table or a combination thereof; Wherein M 2+ comprises divalent magnesium, calcium, strontium, barium, or a combination thereof; Wherein M 4+ comprises tetravalent silicon, titanium, zirconium or a combination thereof.

13. The method according to claim 12, wherein the reaction conditions include one or more of the following: a temperature of 100°C to 500°C; or a pressure of 5 kPa to 30,000 kPa.

14. The catalyst according to any one of claims 12 to 13, wherein M comprises Cu, Co, Fe, Ni, Ru, Rh, Pd, Ir, Pt, Ag, Au or a combination thereof.

15. The catalyst according to any one of claims 12 to 14, wherein M is present in an amount of 0.01 wt% to 50 wt%.

16. The catalyst according to any one of claims 12 to 15, wherein M 2+ O is present in an amount of 1% to 98% by weight.

17. The catalyst according to any one of claims 12 to 16, wherein M 4+ O2 is present in an amount of 1% to 98% by weight.

18. The catalyst according to any one of claims 12 to 17, further comprising: a salt or oxide of a Group 1 metal of the Periodic Table, or a combination thereof.

19. The catalyst according to claim 18, wherein the Group 1 metal is present in an amount of 0.01 wt% to 10 wt%.

Images