METHOD FOR PRODUCING 1-OCTANOL

Abstract

The present invention relates to a process for obtaining 1-octanol which comprises a contact step between ethanol, n-hexanol and a catalyst, wherein said catalyst comprises: i) a metal oxide that comprises the following metals: M1 is at least one bivalent metal selected from Mg, Zn, Cu, Co, Mn, Fe, Ni and Ca; M2 is at least one trivalent metal selected from Al, La, Fe, Cr, Mn, Co, Ni, and Ga; ii) a noble metal selected from Pd, Pt, Ru, Rh and Re; and iii) optionally, comprises V; with the proviso that the catalyst comprises at least V, Ga or any of their combinations.

Claims

1. Process for obtaining 1-octanol which comprises a contact step between ethanol, n-hexanol and a catalyst, wherein said catalyst comprises: i) a metal oxide that comprises the following metals: M1 is at least one bivalent metal selected from Mg, Zn, Cu, Co, Mn, Fe, Ni and Ca; M2 is at least one trivalent metal selected from Al, La, Fe, Cl.sup.−, Mn, Co, Ni, and Ga; ii) a noble metal selected from Pd, Pt, Ru, Rh and Re; and iii) optionally, comprises V; with the proviso that the catalyst comprises at least V, Ga or any of its combinations.

2. The process according to the preceding claim, wherein the catalyst is obtained by a process comprising the following steps: a) total or partial thermal decomposition of a hydrotalcite with the formula
[M1.sub.(1-x)M2.sub.x(OH).sub.2][A.sup.m-.sub.(x/m).nH.sub.2O], where: M1 and M2 is defined in claim 1, A is at least one anion selected from hydroxide, chloride, fluoride, bromide, iodide, nitrate, perchlorate, chlorate, bicarbonate, acetate, benzoate, methanesulfonate, p-toluenesulfonate, phenoxide, alkoxide, carbonate, sulfate, terephthalate, phosphate, hexacyanoferrate (III) and hexacyanoferrate (II), x is a value greater than 0 and less than 1; m is an integer between 1 and 4; and n is greater than 0; b) addition to the metal oxide obtained in step a) of: at least one noble metal selected from Pd, Pt, Ru, Rh and Re; and optionally, V; with the proviso that the catalyst comprises V, Ga or any of its combinations.

3. The process according the preceding claim, wherein the hydrotalcite is obtained by the co-precipitation of M1 and M2 compounds.

4. The process according to any of the preceding claims, wherein M1 is Mg.

5. The process according to any of the preceding claims, wherein M2 comprises Al, Ga or any of its combinations, preferably M2 comprises Al or Al and Ga.

6. The process according to any of the preceding claims, wherein the catalyst comprises V.

7. The process according to any of claims 2 to 6, wherein the thermal decomposition of hydrotalcite is performed by means of calcination under atmosphere of oxygen, nitrogen or any mixture thereof at a temperature ranging between 250° C. and 650° C., preferably between 350° C. and 550° C.

8. The process according to any of claims 2 to 7, wherein A is at least one anion selected from CO.sub.3.sup.2−, HCO.sub.3.sup.−, O.sub.2.sup.− and OH.sup.−.

9. The process according to any of the preceding claims, wherein the V and/or the noble metal is added to the metal oxide by wet impregnation, incipient volume impregnation or deposition-precipitation.

10. The process according to the preceding claim, wherein, following the addition of the noble metal, there is a calcination step and a reduction step subsequent to said calcination.

11. The process according to any of the preceding claims, wherein the contact between the ethanol, n-hexanol and the catalyst is performed at a pressure of up to 120 bar, preferably between 20 and 80 bar.

12. The process according to any of the preceding claims, wherein the contact between the ethanol, n-hexanol and the catalyst is performed under atmosphere of nitrogen, argon, hydrogen or any mixture thereof, preferably in a nitrogen and hydrogen atmosphere.

13. Process for obtaining a catalyst, which comprises the following steps: a) total or partial thermal decomposition of a hydrotalcite with the formula [M1.sub.(1-x) M2.sub.x(OH).sub.2][A.sup.m-.sub.(x/m).nH.sub.2O], to obtain a metal oxide, wherein: M1 is at least one bivalent metal selected from Mg, Zn, Cu, Co, Mn, Fe, Ni and Ca; M2 is at least one trivalent metal selected from Al, La, Fe, Cr, Mn, Co, Ni and Ga; and A is at least one anion selected from hydroxide, chloride, fluoride, bromide, iodide, nitrate, perchlorate, chlorate, bicarbonate, acetate, benzoate, methanesulfonate, p-toluenesulfonate, phenoxide, alkoxide, carbonate, sulfate, terephthalate, phosphate, hexacyanoferrate (Ill) and hexacyanoferrate (II), x is a value greater than 0 and less than 1; m is an integer between 1 and 4; and n is greater than 0, b) addition of V and of at least one noble metal selected from Pd, Pt, Ru, Rh and Re to the solid obtained in the previous step.

14. The process according to the previous claim, characterised in that it further comprises a step (a′) prior to step (a), where the hydrotalcite is synthesised by the co-precipitation of M1 and M2 compounds.

15. The process according to any of claim 13 or 14, wherein the thermal decomposition of step (a) is calcination in an atmosphere of oxygen, nitrogen or any mixture thereof at a temperature ranging between 250° C. and 650° C., preferably between 350° C. and 550° C.

16. The process according to any of claims 13 to 15, wherein the addition of V and/or the addition of the noble metal of step (b) is performed by wet impregnation, incipient volume impregnation or deposition-precipitation.

17. The process according to any claims 13 to 16, wherein M1 is Mg.

18. The process according to any claims 13 to 17, wherein M2 comprises Al, Ga or any of its combinations, preferably M2 comprises Al and Ga.

19. The process according to any of claims 13 to 18, where A is at least one anion selected from CO.sub.3.sup.2−, HCO.sub.3.sup.−, O.sub.2.sup.− and OH.sup.−.

20. The process according to any of claims 13 to 19, wherein the noble metal that is added in step (b) is Pd.

21. The process according to any of claims 13 to 20, which further comprises a step (c), subsequent to (b), where the product obtained in step (b) is calcined.

22. The process according to the preceding claim, which further comprises a reduction step (d), subsequent to (c).

23. A catalyst obtained by means of the process according to any of claims 13 to 22.

24. Use of the catalyst according to the preceding claim, to obtain 1-octanol.

Description

DESCRIPTION OF THE DRAWINGS

[0093] FIG. 1. Shows a comparative graph of the catalytic activities (conversions of EtOH and HexOH and yields to n-ButOH, 1-OctOH and C.sub.4+OH of catalysts based on a HT-1 material (Examples 1, 4 and 7) in an N.sub.2 atmosphere. %: percentage of conversion or yield, as indicated in the x axis; C(EtOH): ethanol conversion, C(HexOH): n-hexanol conversion, μ(n-ButOH): yield to n-ButOH; μ(1-OctOH): yield to 1-octanol; μ(C4+OH): yield to C.sub.4+ alcohols; Graph key: lines: example 1 (HT-1); dots: example 4 (0.70% Pd/HT-1); black: example 7 (0.77% Pd/0.20% V/HT-1).

[0094] FIG. 2. Shows a comparative graph of the catalytic activities (conversions of EtOH and n-HexOH and yields to n-ButOH, 1-OctOH and C.sub.4+OH of catalysts based on a HT-3 material (Examples 2, 5 and 8) in an N.sub.2 atmosphere. Graph key: lines: example 2 (HT-3); dots: example 5 (0.78% Pd/HT-3); black: example 8 (0.75% Pd/0.24% V/HT-3).

[0095] FIG. 3. Shows a comparative graph of the catalytic activities (conversions of EtOH and n-HexOH and yields to n-ButOH, 1-OctOH and C.sub.4+OH of catalysts based on a HT-4 material (Examples 3, 6 and 9) in an N.sub.2 atmosphere. Graph key: lines: example 3 (HT-4); dots: example 6 (0.77% Pd/HT-4); black: example 98 (0.97% Pd/1.0% V/HT-4).

[0096] FIG. 4. Shows a comparative graph of the catalytic activities (conversions of EtOH and n-HexOH and yields to n-ButOH, 1-OctOH and C.sub.4+OH of catalysts based on a HT-4 material with Ga (Examples 10, 11 and 12) in an N.sub.2 atmosphere. Graph key: lines: example 10 (0.29% Ga-HT-4); dots: example 11 (0.87% Pd/0.29% Ga-HT-4); black: example 12 (0.97% Pd/0.29% V/0.29% Ga-/HT-4).

EXAMPLES

[0097] Below we will illustrate the invention by means of assays performed by the inventors, which demonstrate the efficacy of the hydrotalcite-derived catalysts that comprise gallium and/or vanadium in their structure in the obtainment of 1-octanol.

Example 1. Synthesis of the HT-1 Catalyst (Mg/Al Molar Ratio≈1)

[0098] It was prepared by means of a standard co-precipitation process using two solutions. The first solution contained 17.79 g of Mg(NO.sub.3).sub.2.6H.sub.2O and 26.05 g of Al(NO.sub.3).sub.3.9H.sub.2O, dissolved in 48.72 g of Milli-Q water, with a molar concentration of Al+Mg of 1.5. The second solution contained 13.95 g of NaOH and 9.86 g of Na.sub.2CO.sub.3 in 68.85 g of Milli-Q water, and was used to produce the adequate precipitation of the Al and Mg species, and to set the pH of the total mixture at ≈13. Both solutions were added, at a total flow velocity of 20 ml/h for approx. 4 h, to a container under vigorous stirring at room temperature. The gel formed was aged at room temperature for 1-2 h; thereafter, it was filtered and washed with distilled water until the carbonate was not detected in the filtered liquid (at pH≈7). Subsequently, the solid was dried in an oven at 60° C. for 18 h. The hydrotalcite obtained was calcined in air at 450° C. and a mixed oxide called HT-1 was obtained, with a Mg/Al molar ratio≈1.54 and a surface area (BET method) of 310.37 m.sup.2/g. The BET method refers to the Brunauer-Emmett-Teller isotherm method.

Example 2. Synthesis of the HT-3 Catalyst (Mg/Al Molar Ratio≈3)

[0099] It was prepared by means of a standard co-precipitation process using two solutions. The first solution contained 27.99 g of Mg(NO.sub.3).sub.2.6H.sub.2O and 13.65 g of Al(NO.sub.3).sub.3.9H.sub.2O, dissolved in 55.31 g of Milli-Q water, with a molar concentration of Al+Mg of 1.5. The second solution contained 13.13 g of NaOH and 10.23 g of Na.sub.2CO.sub.3 in 73.61 g of Milli-Q water, and was used to produce the adequate precipitation of the Al and Mg species, and to set the pH of the total mixture at ≈13. Both solutions were added, at a total flow velocity of 20 ml/h for approx. 4 h, to a container under vigorous stirring at room temperature. The gel formed was aged at room temperature for 1-2 h; thereafter, it was filtered and washed with distilled water until the carbonate was not detected in the filtered liquid (at pH≈7). Subsequently, the solid was dried in an oven at 60° C. for 18 h. The hydrotalcite obtained was calcined in air at 450° C. and a mixed oxide called HT-3 was obtained, with a Mg/Al molar ratio≈3.10 and a surface area (BET method) of 254.03 m.sup.2/g.

Example 3. Synthesis of the HT-4 Catalyst (Mg/Al Molar Ratio≈4)

[0100] It was prepared by means of a standard co-precipitation process using two solutions. The first solution contained 36.45 g of Mg(NO.sub.3).sub.2.6H.sub.2O and 13.60 g of Al(NO.sub.3).sub.3.9H.sub.2O, dissolved in 67.79 g of Milli-Q water, with a molar concentration of Al+Mg of 1.5. The second solution contained 12.53 g of NaOH and 16.16 g of Na.sub.2CO.sub.3 in 89.63 g of Milli-Q water, and was used to produce the adequate precipitation of the Al and Mg species, and to set the pH of the total mixture at ≈13. Both solutions were added, at a total flow velocity of 20 ml/h for approx. 4 h, to a container under vigorous stirring at room temperature. The gel formed was aged at room temperature for 1-2 h; thereafter, it was filtered and washed with distilled water until the carbonate was not detected in the filtered liquid (at pH≈7). Subsequently, the solid was dried in an oven at 60° C. for 18 h. The hydrotalcite obtained was calcined in air at 450° C. and a mixed oxide called HT-4 was obtained, with a Mg/Al molar ratio≈3.80 and a surface area (BET method) of 257 m.sup.2/g.

Example 4. Synthesis of the 0.70% Pd/HT-1 Catalyst

[0101] It was prepared from the material prepared as described in Example 1, wherein the incorporation of Pd (1.0% by weight, theoretical) into the HT-1 material (Mg/Al≈1) was performed by means of the incipient wetness impregnation method, using, in this case, 0.0360 g of Pd(NH.sub.3).sub.4Cl.sub.2.6H.sub.2O dissolved in 2 ml of Milli-Q water, to impregnate 1.4086 g of HT-1. Once impregnated, the solid obtained was dried in an oven at 100° C. for 12 h; thereafter, it was calcined in air at 450° C. for 6 h, and, subsequently, it was reduced at 450° C. in an H.sub.2 atmosphere for 3 h prior to the catalytic application thereof. The resulting Pd/HT-1 material, characterised by chemical analysis and ICP-MS, contained ≈0.70% by weight of Pd.

Example 5. Synthesis of the 0.78% Pd/HT-3 Catalyst

[0102] It was prepared from the material prepared as described in Example 2, wherein the incorporation of Pd (1.0% by weight, theoretical) into the HT-3 material (Mg/Al≈3) was performed by means of the incipient wetness impregnation method, using, in this case, 0.0308 g of Pd(NH.sub.3).sub.4Cl.sub.2.6H.sub.2O dissolved in 2 ml of Milli-Q water, to impregnate 1.4030 g of HT-3. Once impregnated, the solid obtained was dried in an oven at 100° C. for 12 h; thereafter, it was calcined in air at 450° C. for 6 h, and, subsequently, it was reduced at 450° C. in an H.sub.2 atmosphere for 3 h prior to the catalytic application thereof. The resulting Pd/HT-3 material, characterised by chemical analysis and ICP-MS, contained ≈0.78% by weight of Pd.

Example 6. Synthesis of the 0.77% Pd/HT-4 Catalyst

[0103] It was prepared from the material prepared as described in Example 3, wherein the incorporation of Pd (1.0% by weight, theoretical) into the HT-4 material (Mg/Al≈1) was performed by means of the incipient wetness impregnation method, using, in this case, 0.030 g of Pd(NH.sub.3).sub.4Cl.sub.2.6H.sub.2O dissolved in 2,000 g of Milli-Q water, to impregnate 1.014 g of HT-4. Once impregnated, the solid obtained was dried in an oven at 100° C. for 14-16 h; thereafter, it was calcined in air at 450° C. for 3-4 h, and, subsequently, it was reduced at 350° C. in an H.sub.2 atmosphere for 3 h prior to the catalytic application thereof. The resulting Pd/HT-1 material, characterised by chemical analysis and ICP-MS, contained ≈0.77% by weight of Pd.

Example 7. Synthesis of the 0.77% Pd/0.20% V/HT-1 Catalyst

[0104] It was prepared from the material prepared as described in Example 1, wherein the incorporation of Pd (1.0% by weight, theoretical) and of V (0.2% by weight, theorical) into the HT-1 material (Mg/Al≈1) was performed by means of the incipient wetness impregnation method in two successive steps. In the first step, 0.0353 g of Pd(NH.sub.3).sub.4Cl.sub.2.6H.sub.2O dissolved in 2 ml of Milli-Q water were used to impregnate 1.4037 g of HT-1. Once impregnated, the solid obtained was dried in an oven at 100° C. for 12 h. The incorporation of V (0.2%, theorical) to the solid obtained was performed by means of the incipient wetness impregnation method as well, using 0.0098 g of NH.sub.4VO.sub.3 dissolved in 1 ml of Milli-Q water and 1 ml of oxalic acid 0.2 M to impregnate the solid obtained in the first step. Once impregnated, the solid obtained was dried in an oven at 100° C. for 12 h; thereafter, it was calcined in air at 450° C. for 6 h, and, subsequently, it was reduced at 350° C. in an H.sub.2 atmosphere for 3 h prior to the catalytic application thereof. The resulting Pd/V/HT-1 material, characterised by chemical analysis and ICP-MS, contained ≈0.77% by weight of Pd and 0.2% in weight of V.

Example 8. Synthesis of the 0.75% Pd/0.24% V/HT-3 Catalyst

[0105] It was prepared from the material prepared as described in Example 2, wherein the incorporation of Pd (1.0% by weight, theoretical) and of V (0.2% by weight, theorical) into the HT-3 material (Mg/Al≈3) was performed by means of the incipient wetness impregnation method in two successive steps. In the first step, 0.0300 g of Pd(NH.sub.3).sub.4Cl.sub.2.6H.sub.2O dissolved in 2 ml of Milli-Q water were used to impregnate 1.2094 g of HT-3. Once impregnated, the solid obtained was dried in an oven at 100° C. for 12 h. The incorporation of V (0.2%, theorical) to the solid obtained was performed by means of the incipient wetness impregnation method as well, using 0.0084 g of NH.sub.4VO.sub.3 dissolved in 0.5 ml of Milli-Q water and 1 ml of oxalic acid 0.2 M to impregnate the solid obtained in the first step. Once impregnated, the solid obtained was dried in an oven at 100° C. for 12 h; thereafter, it was calcined in air at 450° C. for 6 h, and, subsequently, it was reduced at 450° C. in an H.sub.2 atmosphere for 3 h prior to the catalytic application thereof. The resulting Pd/V/HT-3 material, characterised by chemical analysis and ICP-MS, contained ≈0.75% by weight of Pd and 0.24% in weight of V.

Example 9. Synthesis of the 0.97% Pd/1.00% V/HT-4 Catalyst

[0106] It was prepared from the material prepared as described in Example 3, wherein the incorporation of Pd (1.0% by weight, theoretical) and of V (2.00% by weight, theorical) into the HT-4 material (Mg/Al≈4) was performed by means of the incipient wetness impregnation method in two successive steps. In the first step, 0.0270 g of Pd(NH.sub.3).sub.4Cl.sub.2.6H.sub.2O dissolved in 2.000 g of Milli-Q water were used to impregnate 1.0000 g of HT-4. The incorporation of V (2.0%, theorical) to the solid obtained was performed by means of the incipient wetness impregnation method as well, using 0.0460 g of NH.sub.4VO.sub.3 dissolved in 2.000 g of Milli-Q water to impregnate the solid obtained in the first step. Once impregnated, the solid obtained was dried in an oven at 100° C. for 14-16 h; thereafter, it was calcined in air at 450° C. for 6 h, and, subsequently, it was reduced at 350° C. in an H.sub.2 atmosphere for 3 h prior to the catalytic application thereof. The resulting Pd/V/HT-4 material, characterised by chemical analysis and ICP-MS, contained ≈0.97% by weight of Pd and 1.0% in weight of V.

Example 10. Synthesis of the 0.29% Ga-HT-4 Catalyst

[0107] It was prepared by means of a standard co-precipitation process using two solutions. The first solution contained 29.89 g of Mg(NO.sub.3).sub.2.6H.sub.2O, 10.90 g of Al(NO.sub.3).sub.3.9H.sub.2O and 0.06 g of Ga(NO.sub.3).sub.3.9H.sub.2O, dissolved in 55.18 g of Milli-Q water, with a molar concentration of (Al+Mg+Ga) of 1.5. The second solution contained 12.52 g of NaOH and 10.52 g of Na.sub.2CO.sub.3 in 72.60 g of Milli-Q water, and was used to produce the adequate precipitation of the Mg, Al and Ga species, and to set the pH of the total mixture at ≈13. Both solutions were added, at a total flow velocity of 30 ml/h for approximately 4 h, to a container under vigorous stirring at room temperature. The gel formed was aged at room temperature for 1-2 h; thereafter, it was filtered and washed with distilled water until the carbonate was not detected in the filtered liquid (at pH≈7). Subsequently, the solid was dried in an oven at 60° C. for 14-16 h. The hydrotalcite (Ga-HT-4) obtained was calcined in air at 450° C. for 3-4 h, to obtain a mixed oxide with a Mg/Al molar ratio≈3.8, a Ga content of 0.29% by weight (measured by chemical analysis and ICP-MS), and a surface area (BET method) of 262 m.sup.2/g.

Example 11. Synthesis of the 0.87% Pd/0.29% Ga-HT-4 Catalyst

[0108] It was prepared from the material prepared as described in Example 10, wherein the incorporation of Pd (1.0% by weight, theoretical) into the Ga-HT-4 material was performed by means of the incipient wetness impregnation method, using, in this case, 0.030 g of Pd(NH.sub.3).sub.4Cl.sub.2.6H.sub.2O dissolved in 1.700 g of Milli-Q water, to impregnate 1.100 g of 0.29% Ga-HT-4. Once impregnated, the solid obtained was dried in an oven at 100° C. for 14-16 h; thereafter, it was calcined in air at 450° C. for 3-4 h, and, subsequently, it was reduced at 350° C. in an H.sub.2 atmosphere for 3 h prior to the catalytic application thereof. The resulting Pd/0.29% Ga-HT-4 material, characterised by chemical analysis and ICP-MS, contained ≈0.87% by weight of Pd.

Example 12. Synthesis of the 0.97% Pd/0.29% V/0.29% Ga-HT-4 Catalyst

[0109] It was prepared from the material prepared as described in Example 10, wherein the incorporation of Pd (1.0% by weight, theoretical) and V (0.2% by weight, theorical) into the Ga-HT-4 material was performed by means of the incipient wetness impregnation method in two successive steps. In the first step, 0.0355 g of Pd(NH.sub.3).sub.4Cl.sub.2.6H.sub.2O dissolved in 2 ml of Milli-Q water were used to impregnate 1.4072 g of 0.29% Ga-HT-4. Once impregnated, the solid obtained was dried in an oven at 100° C. for 14-16 h. The incorporation of V (0.2%, theorical) to the solid obtained was performed by means of the incipient wetness impregnation method as well, using 0.0096 g of NH.sub.4VO.sub.3 dissolved in 1 ml of Milli-Q water and 1 ml of oxalic acid 0.2 M to impregnate the solid obtained in the first step. Once impregnated, the solid obtained was dried in an oven at 100° C. for 1-2 h; thereafter, it was calcined in air at 450° C. for 6 h, and, subsequently, it was reduced at 350° C. in an H.sub.2 atmosphere for 3 h prior to the catalytic application thereof. The resulting Pd/V/0.29% Ga-HT-4 material, characterised by chemical analysis and ICP-MS, contained ≈0.97% by weight of Pd and 0.29% of V.

Example 13. Synthesis of the 4.9% Cu-HT-4 Catalyst

[0110] This catalyst was synthesised to illustrate hydrotalcite-type catalysts containing Cu, such as those cited in application WO2009026523. Various catalysts were synthesised with different concentrations of Cu, and the catalyst that provided the best results, in terms of selectivity and conversion, was selected in order to be compared to the catalysts of the invention.

[0111] It was prepared by means of a standard co-precipitation process using two solutions. The first solution contained 30.0795 g of Mg(NO.sub.3).sub.2.6H.sub.2O, 10.4441 g of Al(NO.sub.3).sub.3.9H.sub.2O and 1.1720 g of Cu(NO.sub.3).sub.2.3H.sub.2O, dissolved in 57.6217 g of Milli-Q water, with a molar concentration of (Al+Mg+Cu) of 1.5. The second solution contained 13.0492 g of NaOH and 10.5207 g of Na.sub.2CO.sub.3 in 74.7069 g of Milli-Q water, and was used to produce the adequate precipitation of the Mg, Al and Cu species, and to set the pH of the total mixture at ≈13. Both solutions were added (total flow velocity=30 ml/h for approximately 4 h) to a container under vigorous stirring at room temperature. The gel formed was aged at room temperature for 1-2 h; thereafter, it was filtered and washed with distilled water until the carbonate was not detected in the filtered liquid (at pH≈7). Subsequently, the solid was dried in an oven at 60° C. for 18 h. The hydrotalcite (Cu-HT-4) obtained was calcined in air at 450° C. for 3-4 h, to obtain a mixed oxide with a Mg/Al molar ratio≈3.8, a Cu content of 4.9% by weight, characterised by chemical analysis and ICP-MS and a surface area (BET method) of 190.08 m.sup.2/g.

Example 14. Synthesis of the 0.98% Pd/0.20% V/4.9% Cu-HT-4 Catalyst

[0112] It was prepared from the material prepared as described in Example 12, wherein the incorporation of Pd (1.0% by weight, theoretical) and V (0.2% by weight, theorical) into the 4.9% Cu-HT-4 material (Mg+Cu/Al≈4) was performed by means of the incipient wetness impregnation method in two successive steps. In the first step, 0.0350 g of Pd(NH.sub.3).sub.4Cl.sub.2.6H.sub.2O dissolved in 2 ml of Milli-Q water were used to impregnate 1.4000 g of 4.9% Cu-HT-4. Once impregnated, the solid obtained was dried in an oven at 100° C. for 12 h. The incorporation of V (0.2%, theorical) to the solid obtained was performed by means of the incipient wetness impregnation method as well, using 0.0090 g of NH.sub.4VO.sub.3 dissolved in 1 ml of Milli-Q water and 1 ml of oxalic acid 0.2 M to impregnate the solid obtained in the first step. Once impregnated, the solid obtained was dried in an oven at 100° C. for 12 h; thereafter, it was calcined in air at 450° C. for 6 h, and, subsequently, it was reduced at 350° C. in an H.sub.2 atmosphere for 3 h prior to the catalytic application thereof. The resulting Pd/V/0.29% Ga-HT-4 material, characterised by chemical analysis and ICP-MS, contained ≈0.98% by weight of Pd and 0.20% of V.

Example 15. Comparative Catalytic Activity of the Catalysts of Examples 1 to 13 Under N.SUB.2 .Atmosphere

[0113] 1750 mg of ethanol, 1790 mg n-hexanol and 350 mg of one of the catalytic materials of Examples 1-13 were introduced into a 12-ml stainless steel autoclave reactor, with a strengthened PEEK-coated (Polyether ethyl ketone) inside and a magnetic stirrer. The reactor was hermetically closed, and the system contained a connector to a pressure meter (manometer), another connector for the loading of gases and a third outlet which made it possible to take samples at different time intervals. The reactor was initially pressurised with 24 bars of N.sub.2, and heated to 250° C. under continuous stirring, until the total system pressure reached approx. 35-40 bars (reaction time=0). Liquid samples (≈50-100 μl) were taken at different time intervals until 17 hours of reaction. The samples were filtered and diluted in a 2% by weight of chlorobenzene in acetonitrile standard solution, and analysed by means of gas chromatography in a GC-3900 Varian equipped with an FID detector and a 60-m TRB-624 capillary column.

[0114] The ethanol conversion, in molar percentage (conv. EtOH), was calculated from the composition of the mixture obtained:

(initial moles of ethanol−final moles of ethanol)/(initial moles of ethanol*100)

[0115] The n-hexanol conversion, in molar percentage (conv. n-HexOH), was calculated from the composition of the mixture obtained:

(initial moles of n-hexanol−final moles of n-hexanol)/(initial moles of n-hexanol*100)

[0116] The total yield of n-butanol, in molar percentage (Yield n-ButOH) was calculated as:

(moles of n-butanol/moles of total products)*Conv.EtOH/100

[0117] The total yield of 1-octanol, in molar percentage (Yield 1-OctOH) was calculated as:

(moles of 1-octanol/moles of total products)*Conv.EtOH/100

[0118] The total yield of linear C.sub.4+ alcohols, in molar percentage (Yield linear C.sub.4+OH), which includes n-butanol and 1-octanol of course, was calculated as:

(moles of linear C.sub.4+/moles of total products)*Conv.EtOH/100

[0119] The total yield of branched C.sub.4+ alcohols, in molar percentage (Yield branched C.sub.4+OH), was calculated as:

(moles of branched C.sub.4+/moles of total products)*Conv.EtOH/100

[0120] In this manner, the following results were obtained:

TABLE-US-00001 TABLE 1 Catalytic activity of different mixed metal oxides in the transformation of ethanol + n-hexanol under nitrogen atmosphere. T Conv Conv. n- Yield Yield Yield C.sub.4+OH Ex. Catalyst (h) EtOH HexOH n-ButOH 1-OctOH Linear branched 1 HT-1 5 11.4 3.3 0.25 0.18 0.4 0.0 2 HT-3 5 11.2 2.8 1.50 1.08 2.5 0.0 3 HT-4 5 22.3 3.4 10.56 3.95 14.9 0.4 4 0.70% Pd/HT-1 5 36.6 10.3 14.50 6.20 21.7 0.9 5 0.78% Pd/HT-3 5 34.7 8.7 9.44 4.24 14.4 1.3 6 0.77% Pd/HT-4 5 34.5 8.6 13.21 6.42 21.3 1.0 7 0.77% Pd/0.20% 5 61.6 23.2 11.61 7.82 25.4 1.4 V/HT-1 8 0.75% Pd/0.24% 5 76.2 18.0 17.57 19.55 42.2 2.4 V/HT-3 9 0.97% Pd/1.0% 5 37.4 11.1 15.46 8.55 23.0 1.0 V/HT-4 10 0,29% Ga-HT-4 5 26.4 4.6 8.77 3.78 12.6 0.4 11 0,87% Pd/0,29% 5 42.6 21.3 16.52 5.69 19.0 1.1 Ga-HT-4 12 0,97% Pd/0,29% 5 40.9 10.7 14.93 8.30 25.6 1.1 V/0,29% Ga- HT-4 13 4,9% Cu-HT-4 5 22.4 8.0 4.03 4.99 9.6 0.8 14 0,98% Pd/0,20% 5 36.1 7.9 7.28 3.87 13.1 0.4 V/4,9% Cu- HT-4

[0121] These results show that the incorporation of vanadium into hydrotalcite-derived catalysts with different Mg/Al ratio in their structure achieve higher yields both to n-butanol and to 1-octanol, and in general, higher yield to C.sub.4+ alcohols than their analogue catalyst without vanadium. Not only that but also the catalyst show an improved catalytic activity (ethanol and n-hexanol conversion), even with V concentrations under 1% as it can be seen in FIGS. 1, 2 and 3.

[0122] Comparison of the results of the examples 3, 6, 9 and 10-12 shows that the incorporation of vanadium into hydrotalcite-derived catalysts comprising Ga in their structure gives higher yields to 1-octanol, and in general, higher yield to C.sub.4+ alcohols than their analogue catalyst without vanadium. This effect occurs even with V concentrations lower than 0.3%, as it can be seen in FIG. 4. This indicates the higher stability of the catalyst of the invention under reaction conditions.

[0123] If we compare the examples 6, 8, 9, 11, 13 and 14, the results show that the incorporation of vanadium into hydrotalcite-derived catalysts with different Mg/Al ratios gives higher yields to 1-octanol, and in general, higher yield to C.sub.4+ alcohols than their analogue catalyst without vanadium. However, the production of C.sub.4+OH decreases substantially when the catalyst comprises Cu in their structure, even in the presence of Pd and V. This indicates the higher stability of the catalyst of the invention under reaction conditions.

Example 16. Comparative Catalytic Activity of the Catalysts of Examples 6, 9 and 11 Under N.SUB.2 .Atmosphere with Ethanol Only (without n-Hexanol)

[0124] 3500 mg of ethanol, and 200 mg of one of the catalytic materials of Examples 6, 9 and 11 were introduced into a 12-ml stainless steel autoclave reactor, with a strengthened PEEK-coated (Polyether ethyl ketone) inside and a magnetic stirrer. The reactor was hermetically closed, and the system contained a connector to a pressure meter (manometer), another connector for the loading of gases and a third outlet which made it possible to take samples at different time intervals. The reactor was initially pressurised with 24 bars of N.sub.2, and heated to 200° C. under continuous stirring, until the total system pressure reached approx. 30 bars (reaction time=0). Liquid samples (≈50-100 μl) were taken at different time intervals until 17 hours of reaction. The samples were filtered and diluted in a 2% by weight of chlorobenzene in acetonitrile standard solution, and analysed by means of gas chromatography in a GC-3900 Varian equipped with an FID detector and a 60-m TRB-624 capillary column.

[0125] The following results were obtained:

TABLE-US-00002 TABLE 2 Catalytic activity of different mixed metal oxides in the transformation of ethanol under nitrogen atmosphere. Yieldt Yield Yield T Conv n- Yield n- 1- C.sub.4+OH Ex. Catalyst (h) EtOH ButOH HexOH OctOH lineal branched 6 0.77% Pd/ 5 15.5 11.9 1.9 0.4 14.6 0.2 HT-4 9 0.97% Pd/ 5 14.0 9.4 1.8 0.2 11.6 0.1 1.0%V/ HT-4 1 0,87% 5 15.8 12.1 1.9 0.3 14.4 0.3 Pd/0,2 1 9% Ga- HT-4

[0126] The rest of the products up to 100% comprise mainly aldehydes (ethanal, butanal, hexanal, ethylacetate and diethoxyethane.

[0127] These results show that the catalyst of the invention with ethanol as a reagent do not yield 1-octanol in a high percentage. It is therefore shown that n-hexanol and ethanol is required to obtain high yields of 1-octanol.

[0128] Moreover, the percentage of branched products obtained is higher if no n-hexanol is used.

Example 17. Comparative Catalytic Activity of the Catalysts of Examples 6, 9, 11 and 12 Under N.SUB.2 .Atmosphere with n-Butanol as Feedstock (Neither Ethanol Nor n-Hexanol)

[0129] 3500 mg of n-butanol, and 350 mg of one of the catalytic materials of Examples 6, 9, 11 and 12 were introduced into a 12-ml stainless steel autoclave reactor, with a strengthened PEEK-coated (Polyether ethyl ketone) inside and a magnetic stirrer. The reactor was hermetically closed, and the system contained a connector to a pressure meter (manometer), another connector for the loading of gases and a third outlet which made it possible to take samples at different time intervals. The reactor was initially pressurised with 24 bars of N.sub.2, and heated to 250° C. under continuous stirring, until the total system pressure reached approx. 40 bars (reaction time=0). Liquid samples (≈50-100 μl) were taken at different time intervals until 17 hours of reaction. The samples were filtered and diluted in a 2% by weight of chlorobenzene in acetonitrile standard solution, and analysed by means of gas chromatography in a GC-3900 Varian equipped with an FID detector and a 60-m TRB-624 capillary column.

[0130] The following results were obtained:

TABLE-US-00003 TABLE 3 Catalytic activity of different mixed metal oxides in the transformation of n-butanol under nitrogen atmosphere. Conv. Yield T n- Yield Yield Yield C.sub.4+OH Ex. Catalyst (h) ButOH Butanal Aldehydes 1-OctOH lineal branched 6 0.77% Pd/HT-4 5 17.1 2.9 0.6 0.1 6.4 5.3 9 0.97% Pd/1.0 5 35.5 1.4 0.6 0.6 22.5 6.4 % V/HT-4 11 0,87% Pd/0,2 5 32.9 1.7 0.6 0.2 21.1 6.8 9% Ga-HT-4 12 0,97% Pd/0,2 5 25.9 1.9 0.5 0.2 14.8 6.5 9% V/0,29% Ga-HT-4

[0131] The rest of the products up to 100% comprise mainly 3-methyl-2-butanone, butyl butanoate, n-butyl ether, 4-methyl-2-hexanone, 1,1-dibutoxybutane.

[0132] These results show that the catalyst of the invention with n-butanol as a reagent do not yield 1-octanol in a high percentage. It is therefore shown that n-hexanol and ethanol is required to obtain high yields of 1-octanol.

[0133] Moreover, the percentage of branched products obtained is higher if neither n-hexanol nor ethanol is used.