A preparation method of an octene aldehyde liquid phase hydrogenation catalyst

Abstract

This invention relates to the field of catalyst preparation technology, and particularly to a method for preparing an octenal liquid-phase hydrogenation catalyst. The method comprises the following steps: Step 1: Mixing Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O in the specified amounts to prepare solution a; Step 2: Mixing Na2CO3 and NaOH in the specified amounts to prepare solution b; Step 3: Placing solutions a and b separately in dropping funnels, and adding each solution dropwise to a three-necked flask placed in a constant temperature water bath at 60℃~80℃, while continuously stirring; Step 4: After aging for 2h~12h, filtering and washing the precipitate with distilled water, followed by drying and calcination, to obtain the catalyst precursor. The catalyst precursor prepared by this invention, after reduction and activation, is used in the liquid-phase hydrogenation of octenal to octanol, exhibiting high catalytic hydrogenation activity and high selectivity for octanol.

Description

Technical fields:

[0001] This invention relates to the field of catalyst preparation technology, and in particular to a method for preparing an octenal liquid-phase hydrogenation catalyst. Background technology:

[0002] Chinese patents CN105080549A and CN105080549B disclose a catalyst for the gas-phase hydrogenation of octenal to 2-ethylhexanol and its preparation method. A highly selective octenal hydrogenation catalyst prepared by distributed precipitation is proposed, simultaneously addressing the problem of catalyst pulverization during use. The catalyst's main components are 25%–35% copper oxide, 45%–60% zinc oxide, 2%–10% alumina, 2%–10% silica, and 0.01%–1% additives. The catalyst has a specific surface area of ​​30 m². 2 / g~60m 2 The catalyst prepared by this invention has high activity and selectivity for 2-ethylhexanol, while also exhibiting better performance strength and a lower color number, making it suitable for the gas-phase hydrogenation of octenal to 2-ethylhexanol.

[0003] Chinese patent CN114082421A discloses a hydrogenation catalyst, its preparation method, and its application in the hydrogenation of isooctene aldehyde. The hydrogenation catalyst comprises a support and an active component supported on the support, wherein the support is alumina and / or phosphorus-modified alumina, and the active component is nickel; the specific surface area of ​​the hydrogenation catalyst is 200–630 m². 2 / g, pore volume is 2-4cm³ 3 / g, with a most probable pore size of 10–30 nm. Applying this hydrogenation catalyst to the hydrogenation of isoocteneal to isooctaldehyde and isooctyl alcohol can improve catalytic activity and selectivity.

[0004] Chinese patent CN105854919A discloses a low-temperature hydrogenation catalyst for α,β-unsaturated aldehydes, its preparation method, and its application. The catalyst described in this invention is a hexagonal boron nitride supported noble metal catalyst, prepared by impregnating an active noble metal salt onto a pretreated support and then reducing it. Through precise control and effective combination of support pretreatment, impregnation, and reduction treatment, the active component can be effectively dispersed on the support, exhibiting excellent performance even at low concentrations of the noble metal active component.

[0005] Chinese patent CN1478596A discloses a process for producing isooctanol by hydrogenation of a mixture of isooctaldehyde and the catalyst used therein, particularly relating to a process for producing isooctanol by liquid-phase hydrogenation of a mixture of isooctaldehyde and octenol using a novel catalyst and the catalyst used therein. This catalyst uses metallic nickel as the active component, alkaline earth metal oxides and / or alumina as promoters, and a silicon-containing compound as a support. The raw material for the support is a porous silicon-containing compound and / or a silicon-containing compound that is viscous in aqueous solution; the active component nickel is loaded onto the support by co-precipitation, kneading, or co-precipitation-kneading, and then calcined at 300–800°C. Summary of the Invention:

[0006] The technical problem to be solved by this invention is to provide a method for preparing an octenal liquid-phase hydrogenation catalyst. This method enables the prepared catalyst precursor, after reduction and activation, to be used in the octenal liquid-phase hydrogenation reaction to produce octanol. This method features high catalytic hydrogenation activity and high selectivity for the octanol product. It overcomes the shortcomings of existing octenal liquid-phase hydrogenation catalysts, such as low activity, low selectivity, and high impurity content in the hydrogenated octanol product.

[0007] The technical solution adopted in this invention is: a method for preparing an octenal liquid-phase hydrogenation catalyst, the steps of which are as follows:

[0008] Step 1: Mix Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O in the specified amounts to prepare solution a;

[0009] Step 2: Mix Na2CO3 and NaOH evenly according to the molar amounts to prepare solution b;

[0010] Step 3: Place the prepared solutions a and b into dropping funnels respectively, and add the two solutions dropwise into a three-necked flask placed in a constant temperature water bath at 60℃~80℃, while stirring continuously to carry out the reaction;

[0011] Step 4: After aging for 2 to 12 hours, the precipitate is filtered and washed with distilled water, then dried and calcined to obtain the catalyst precursor.

[0012] Furthermore, in step one, the molar ratio of Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O is x:y:6, where x+y+6=10.

[0013] Furthermore, in step two, the molar ratio of Na2CO3 to NaOH is 5:1 to 9:1.

[0014] Furthermore, after solution a reacts with solution b in step three, the pH value of the solution is controlled to be 9-10.

[0015] Furthermore, in step four, the precipitate after the reaction of solution a and solution b is filtered and washed until the upper washing liquid is neutral.

[0016] Furthermore, in step four, the precipitate is washed with distilled water, dried in an oven at 120°C, and calcined in a muffle furnace at 500°C.

[0017] Furthermore, the reduction and activation conditions for the prepared catalyst precursor are as follows: reduction at 500°C for 12 hours in a mixed gas with a hydrogen-nitrogen flow rate of 1:3.

[0018] The beneficial effects of this invention are: the catalyst precursor prepared by this invention, after reduction and activation, is used in the liquid-phase hydrogenation of octenal to octanol reaction, which has the characteristics of high catalytic hydrogenation activity and high selectivity for octanol product. Attached image description:

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 The image shows the H2-TPR diagram of the catalyst in Example 1. Detailed implementation method:

[0021] Comparative Example 1

[0022] Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were mixed in a molar ratio of 3:1 to prepare solution a, and an equal volume of solution a was impregnated on γ-Al2O3 (Ni, Cu, Al molar ratio of 3:1:6). After standing for 24 h, the solution was dried in an oven at 120 °C and then calcined in a muffle furnace at 500 °C to obtain catalyst precursor X.

[0023] Example 1

[0024] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 3:1:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 7:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in a 65°C constant-temperature water bath, with continuous stirring until the pH of the mixed solution was 9-10. After aging for 6 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120°C, and finally calcined in a muffle furnace at 500°C to obtain catalyst precursor A.

[0025] Example 2

[0026] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 4:0:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 7:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in a 65°C constant-temperature water bath, with continuous stirring until the pH of the mixed solution was 9-10. After aging for 6 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120°C, and finally calcined in a muffle furnace at 500°C to obtain catalyst precursor B.

[0027] Example 3

[0028] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 2:2:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 7:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in a 65℃ constant-temperature water bath, with continuous stirring until the pH of the mixed solution was 9-10. After aging for 6 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120℃, and finally calcined in a muffle furnace at 500℃ to obtain catalyst precursor C.

[0029] Example 4

[0030] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 0:4:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 7:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in a 65℃ constant-temperature water bath, with continuous stirring until the pH of the mixed solution was 9-10. After aging for 6 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120℃, and finally calcined in a muffle furnace at 500℃ to obtain catalyst precursor D.

[0031] Example 5

[0032] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 3:1:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 5:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in a 65°C constant-temperature water bath, with continuous stirring until the pH of the mixed solution was 9-10. After aging for 6 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120°C, and finally calcined in a muffle furnace at 500°C to obtain catalyst precursor E.

[0033] Example 6

[0034] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 3:1:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 9:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in a 65℃ constant-temperature water bath, with continuous stirring until the pH of the mixed solution was 9-10. After aging for 6 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120℃, and finally calcined in a muffle furnace at 500℃ to obtain catalyst precursor F.

[0035] Example 7

[0036] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 3:1:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 7:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in a 60℃ constant-temperature water bath, with continuous stirring until the pH of the mixed solution was 9-10. After aging for 6 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120℃, and finally calcined in a muffle furnace at 500℃ to obtain catalyst precursor G.

[0037] Example 8

[0038] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 3:1:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 7:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in an 80℃ constant-temperature water bath, with continuous stirring until the pH of the mixed solution was 9-10. After aging for 6 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120℃, and finally calcined in a muffle furnace at 500℃ to obtain catalyst precursor H.

[0039] Example 9

[0040] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 3:1:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 7:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in a 65°C constant-temperature water bath, with continuous stirring until the pH of the mixed solution reached 9-10. After aging for 2 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120°C, and finally calcined in a muffle furnace at 500°C to obtain catalyst precursor I.

[0041] Example 10

[0042] First, Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O were mixed evenly in a molar ratio of 3:1:6 to prepare solution a. Next, a mixed solution b was prepared, consisting of Na2CO3 and NaOH in a molar ratio of 7:1. Solutions a and b were placed separately in dropping funnels, and each solution was added dropwise to a three-necked flask placed in a 65℃ constant-temperature water bath, with continuous stirring until the pH of the mixed solution was 9-10. After aging for 12 hours, the precipitate was filtered and washed until the upper washing liquid was neutral, then dried in an oven at 120℃, and finally calcined in a muffle furnace at 500℃ to obtain catalyst precursor J.

[0043] The catalyst precursors prepared in Comparative Example 1 and Examples 1-10 were activated by reduction and then used for the liquid-phase hydrogenation of octenal to octanol under mild conditions of 120℃~130℃. The reaction performance is shown in Table 1.

[0044] Table 1. Liquid-phase hydrogenation performance of the catalyst for octenal.

[0045] catalyst Octenal conversion rate (%) Octyl alcohol selectivity (%) A 99.9 99.7 B 90.6 98.0 C 96.7 98.8 D 81.2 89.9 E 95.4 99.0 F 94.3 99.2 G 98.2 99.6 H 97.9 99.5 I 96.8 99.0 J 99.4 99.6 X 87.3 97.6

[0046] As shown in Table 1, the catalyst prepared by this invention has the characteristics of high catalytic hydrogenation activity and high selectivity for octanol.

[0047] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. An application of liquid-phase hydrogenation of octenal to octanol, characterized in that: The preparation method of the catalyst precursor is as follows: Step 1: Mix Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O evenly according to the amount of substance to prepare solution a; Step 2: Mix Na2CO3 and NaOH evenly according to the molar amounts to prepare solution b; Step 3: Place the prepared solutions a and b into dropping funnels respectively, and add the two solutions dropwise into a three-necked flask placed in a constant temperature water bath at 60℃~80℃, while stirring continuously to carry out the reaction; Step 4: After aging for 2 to 12 hours, the precipitate is filtered and washed with distilled water, then dried and calcined to obtain the catalyst precursor. In step one, the molar ratio of Ni(NO3)2·6H2O, Cu(NO3)2·3H2O, and Al(NO3)3·9H2O is x:y:6, where x+y+6=10.

2. The application of octenal liquid-phase hydrogenation to octanol according to claim 1, characterized in that: In step two, the molar ratio of Na2CO3 to NaOH is 5:1 to 9:

1.

3. The application of the liquid-phase hydrogenation of octenal to octanol according to claim 1, characterized in that: After solution a reacts with solution b in step three, the pH value of the solution is controlled to be 9-10.

4. The application of octenal liquid-phase hydrogenation to octanol according to claim 1, characterized in that: In step four, the precipitate after the reaction of solution a and solution b is filtered and washed until the upper washing liquid is neutral.

5. The application of the liquid-phase hydrogenation of octenal to octanol according to claim 1, characterized in that: In step four, the precipitate is washed with distilled water, dried in a 120°C oven, and calcined in a muffle furnace at 500°C.

6. The application of the liquid-phase hydrogenation of octenal to octanol according to claim 1, characterized in that: The reduction and activation conditions for the prepared catalyst precursor are as follows: reduction at 500°C for 12 hours in a mixed gas with a hydrogen-nitrogen flow rate of 1:3.

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