Preparation and application of a bimetallic phthalocyanine catalyst
By designing a bimetallic phthalocyanine catalyst, the problems of insufficient activity, poor stability, and numerous side reactions of existing catalysts in the hydrogenation of organic acids to alcohols have been solved, achieving efficient and selective alcohol production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG UNIV OF TECH
- Filing Date
- 2026-02-11
- Publication Date
- 2026-06-09
AI Technical Summary
Existing catalysts for the hydrogenation of organic acids to alcohols suffer from problems such as high cost, insufficient activity, poor stability, and numerous side reactions. In particular, under high temperature and high pressure conditions, single metal phthalocyanine catalysts are prone to carbon-carbon bond breakage, resulting in limited conversion rates.
By employing bimetallic phthalocyanine catalysts, different substituents of phthalocyanine are combined with two metals to form bimetallic phthalocyanine compounds. The electronic effects and spatial configuration of these compounds inhibit carbon-carbon bond breaking, thereby improving the selectivity and stability of the hydrogenation reaction.
This method achieves highly efficient catalytic hydrogenation of organic acids to alcohols, improves the selectivity and yield of target alcohols, demonstrates excellent acid hydrogenation catalytic effect, and has broad application prospects.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of industrial catalysis and catalyst technology, specifically relating to a bimetallic phthalocyanine catalyst, its preparation method, and its application. Background Technology
[0002] Hydrogenation of organic acids to alcohols is a crucial technological pathway for developing high-value chemicals from biomass and renewable carbon sources such as carbon dioxide. Traditional alcohol synthesis methods (such as syngas-to-methanol and petroleum-based higher alcohols) generally suffer from high energy consumption, demanding reaction conditions, and reliance on fossil fuels. In contrast, many organic acids (such as acetic acid, lactic acid, and succinic acid) can be derived directly or indirectly from biomass platform compounds or carbon dioxide conversion. Hydrogenation of these compounds to produce corresponding alcohols (such as ethanol, 1,2-propanediol, and 1,4-butanediol) offers potential advantages such as sustainable raw material availability and shorter reaction pathways.
[0003] However, the industrial application of this technology still faces challenges, the core of which lies in catalyst performance. Due to the highly polarized C=O bonds in organic acid molecules and the high stability requirements of acidic environments, hydrogenation reaction conditions are relatively stringent, with early technologies often requiring high temperatures and hydrogen pressures. Existing catalyst systems, including noble metal-based catalysts (such as Pt, Ru, Ir, etc.) and non-noble metal catalysts (such as Cu-based catalysts), still face some bottlenecks in practical applications. For noble metal catalysts, the main problems are high cost and the tendency for side reactions under certain reaction conditions, leading to unsatisfactory selectivity for the target alcohol. While non-noble metal catalysts are cheaper, they often suffer from relatively insufficient activity or poor stability in aqueous or acidic environments. Single-metal phthalocyanine catalysts exhibit good stability, and corresponding acid hydrogenation reactions have been reported; however, they are prone to side reactions under high temperature and pressure conditions, resulting in limited conversion rates. They also suffer from carbon-carbon bond breaking, and mitigating the impact of these side reactions often comes at the cost of reduced hydrogenation efficiency. Furthermore, the hydrogenation efficiency using metal phthalocyanine catalysts needs further improvement. Therefore, developing catalysts that combine high activity, high selectivity, and excellent stability is key to achieving the efficient and economical conversion of various organic acids into target alcohols. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-performance, low-cost metal phthalocyanine catalyst suitable for the direct hydrogenation of acids to alcohols. It can effectively avoid the side reaction problem of carbon-carbon bond breaking, and the catalyst performance can be adjusted by selecting metal phthalocyanines with different substituents.
[0005] The technical solution adopted in this invention is as follows: A bimetallic phthalocyanine catalyst comprising a bimetallic phthalocyanine compound, wherein the phthalocyanine structure is composed of two metals, M (from different metal salts), with different substituents of phthalocyanine combined with two metals.
[0006] Its general structural formula is as follows:
[0007] (I) In the formula, M is a metallic element, selected from two of the transition metals and tin; R1~R 16 Each is independently selected from H and at least one of the following groups: C3-C6 alkyl, C1-C6 alkoxy.
[0008] Preferably, in the formula, M is selected from two of copper, ruthenium, zinc, nickel, palladium, iron, and tin, and the mass of any one of the metal elements accounts for 30%-70% of the total mass of the metal elements.
[0009] Preferably, in the formula, R1~R 16 Each is independently selected from H and at least one of the following groups: isopropyl, n-butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, butoxy.
[0010] The present invention also provides a method for preparing any of the above-mentioned bimetallic phthalocyanine catalysts, comprising: the bimetallic phthalocyanine compound is prepared by reacting a phthalonitrile derivative with a metal salt containing a metal element M, wherein the metal element M is selected from at least two of transition metals and tin.
[0011] Preferably, the substituent (R) on the benzene ring in the phthalonitrile derivative is selected from H and at least one of the following groups: C3-C6 alkyl, C1-C6 alkoxy.
[0012] Preferably, the substituent on the benzene ring in the phthalonitrile derivative is selected from any one of isopropyl (-CH(CH3)2), n-butyl (-CH2CH2CH2CH3), isobutyl (-CH2CH(CH3)2), methoxy (-OCH3), tert-butyl (-C(CH3)3), butoxy (-OCH2CH2CH2CH3), ethoxy (-OCH2CH3), n-propoxy (-OCH2CH2CH3) and H, more preferably butoxy and H.
[0013] Preferably, the metal salt is selected from at least one of the chloride salts (hydrochloride salts), sulfates, carbonates, nitrates, and acetates corresponding to the metal element M; more preferably, the metal salt is selected from at least two of the following: stannous chloride, copper sulfate, copper carbonate, copper nitrate, ferric sulfate, zinc carbonate, zinc nitrate, ferric acetate, tin sulfate, nickel nitrate, nickel sulfate, nickel chloride, zinc chloride, tin chloride, palladium acetate, ruthenium chloride, and copper chloride, more preferably ruthenium chloride and tin chloride; even more preferably, the metal salt includes a mixture of ruthenium salt and tin salt, wherein the molar ratio of the two metal salts, calculated by metal element, is 1:1 to 2:1, more preferably 1:1 to 1.5:1.
[0014] Preferably, the synthesis reaction of the bimetallic phthalocyanine compound is carried out under the protection of an inert gas; preferably, the inert gas includes at least one of nitrogen, argon, or helium.
[0015] Preferably, in the reaction, the molar ratio of the phthalonitrile derivative to the metal salt is 4:1 to 6:1, more preferably 4.5:1 to 5.5:1.
[0016] Preferably, the reaction is carried out in an organic solvent; more preferably, the organic solvent is selected from at least one of N,N-dimethylformamide and triethylene glycol dimethyl ether, and even more preferably triethylene glycol dimethyl ether.
[0017] Preferably, the reaction temperature is 150-250℃, more preferably 170-220℃, and the reaction time is not less than 4 hours, more preferably 4-12 hours, and even more preferably 6-8 hours.
[0018] The present invention also provides an application of any of the above-described bimetallic phthalocyanine catalysts in the fields of catalysts and chemical reactions.
[0019] Preferably, the chemical reaction includes an acid hydrogenation reaction to produce an alcohol.
[0020] Compared with existing technologies, the beneficial effects of this invention include: This invention proposes a novel modification strategy for phthalocyanine metal catalysts: sterically hindered alkyl or alkoxy groups are used to modify metal phthalocyanines, and two or more metal phthalocyanines are combined to obtain a bimetallic phthalocyanine catalyst. Utilizing its unique electronic effects and spatial configuration, it selectively inhibits the more sterically demanding C-C breakage pathway in hydrogenation reactions without altering the hydrogenation performance, thus improving the selectivity of the target alcohol. It can be used for highly efficient catalytic acid hydrogenation reactions, exhibiting excellent acid hydrogenation catalytic effects. Applied to the reaction of acid hydrogenation to alcohols, it demonstrates high yields and has broad application prospects. Detailed Implementation
[0021] To better clarify and understand the purpose, process, and advantages of this invention, specific embodiments are provided below to further describe and illustrate the technical solutions and implementation methods of this invention clearly, completely, and in detail. It should be understood that these methods and specific operating processes are only some embodiments of this invention, not all embodiments. The described specific implementation methods are limited to illustrating and explaining this invention and do not limit it. All other implementation methods obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0022] Unless otherwise specified, the experimental methods and conditions used in the embodiments of this invention are conventional methods and conditions. The materials, reagents, and instruments used in the embodiments, unless otherwise specified, can be obtained commercially or prepared by conventional methods. The reaction conditions described in the invention can all achieve the reactions and obtain the desired products. Due to space limitations, some embodiments are listed below to further illustrate the advantages of the technical solution of this invention.
[0023] Example 1: Synthesis of Butoxy Bimetallic Ruthenium Phthalocyanine
[0024] 4-Butoxyphthalonitrile (5.0 mmol, 1.02 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with ruthenium chloride (0.5 mmol, 0.13 g) and stannous chloride (0.5 mmol, 0.095 g) in a molar ratio of 5.0:0.5:0.5. The reaction mixture was stirred at 200 °C for 7 hours under argon protection. After filtration, the mixture was washed with ethanol and dilute hydrochloric acid and dried to give butoxybimetallic ruthenium phthalocyanine tin in 95.4% yield.
[0025] ICP analysis revealed that Ru comprised 60.4% and Sn 39.6% of the total mass of the metal elements, consistent with the reaction.
[0026] Example 2: 4-Isopropylphthalonitrile (4.5 mmol, 0.77 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with zinc acetate (0.5 mmol, 0.11 g) and nickel chloride (0.5 mmol, 0.065 g) in a molar ratio of 4.5:0.5:0.5. The reaction mixture was stirred at 190 °C for 8 hours under argon protection. After filtration, the mixture was washed with ethanol and dilute hydrochloric acid and dried to give isopropyl bimetallic zinc nickel phthalocyanine in 94.3% yield.
[0027] ICP analysis revealed that the proportions of Zn and Ni in the total mass of the metal elements were 51.2% and 48.8%, respectively, which is consistent with the reaction.
[0028]
[0029] Example 3: 4-tert-butylphthalonitrile (5.2 mmol, 1.01 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with copper nitrate (0.5 mmol, 0.094 g) and nickel chloride (0.5 mmol, 0.065 g) in a molar ratio of 5.2:0.5:0.5. The reaction mixture was stirred at 210 °C for 6.5 h under argon protection. After filtration, the solution was washed with ethanol and dilute hydrochloric acid and dried to give tert-butylbimetallic copper nickel phthalocyanine in 89.8% yield.
[0030] ICP analysis revealed that Cu comprised 52.4% and Ni comprised 47.6% of the total mass of the metal elements, consistent with the reaction.
[0031]
[0032] Example 4: 4-Ethoxyphthalonitrile (5.0 mmol, 0.92 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with stannous chloride (0.5 mmol, 0.095 g) and zinc acetate (0.5 mmol, 0.11 g) in a molar ratio of 5.0:0.5:0.5. The reaction mixture was stirred at 180 °C for 8 hours under argon protection. After filtration, the mixture was washed with ethanol and dilute hydrochloric acid and dried to give ethoxybimetallic tin phthalocyanine zinc in 92.2% yield.
[0033] ICP analysis showed that Sn accounted for 35.4% and Zn for 64.6% of the total mass of the metal elements, which is consistent with the reaction.
[0034]
[0035] Example 5: 4-tert-butylphthalonitrile (5.0 mmol, 0.94 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with nickel chloride (0.5 mmol, 0.065 g) and stannous chloride (0.5 mmol, 0.095 g) in a molar ratio of 5.0:0.5:0.5. The reaction mixture was stirred at 205 °C for 7 hours under argon protection. After filtration, the mixture was washed with ethanol and dilute hydrochloric acid and dried to give tert-butylbimetallic phthalocyanine nickel tin in 95.4% yield.
[0036] ICP analysis revealed that the proportions of Ni and Sn in the total mass of the contained metal elements were 33.1% and 66.9%, respectively, which is consistent with the reaction.
[0037]
[0038] Example 6: 4-Methoxyphthalonitrile (4.8 mmol, 0.78 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with zinc acetate (0.5 mmol, 0.11 g) and copper nitrate (0.5 mmol, 0.094 g) in a molar ratio of 4.8:0.5:0.5. The reaction mixture was stirred at 195 °C for 7.5 h under argon protection. After filtration, the mixture was washed with ethanol and dilute hydrochloric acid and dried to give methoxybimetallic phthalocyanine copper zinc in 93.9% yield.
[0039] ICP analysis showed that Cu accounted for 50.4% and Zn accounted for 49.6% of the total mass of the metal elements, which is consistent with the reaction.
[0040]
[0041] Example 7: 4-n-propoxyphthalonitrile (5.0 mmol, 0.97 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with copper nitrate (0.5 mmol, 0.094 g) and stannous chloride (0.5 mmol, 0.095 g) in a molar ratio of 5.0:0.5:0.5. The reaction mixture was stirred at 215 °C for 6 hours under argon protection. After filtration, the mixture was washed with ethanol and dilute hydrochloric acid and dried to give n-propoxybimetallic copper phthalocyanine tin in 93.7% yield.
[0042] ICP analysis revealed that Cu comprised 34.8% and Sn comprised 65.2% of the total mass of the metal elements, consistent with the reaction.
[0043]
[0044] Example 8: 4-n-Butylphthalonitrile (5.0 mmol, 0.98 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with nickel chloride (0.5 mmol, 0.065 g) and zinc acetate (0.5 mmol, 0.11 g) in a molar ratio of 5.0:0.5:0.5. The reaction mixture was stirred at 200 °C for 7 hours under argon protection. After filtration, the solution was washed with ethanol and dilute hydrochloric acid and dried to give n-butylbimetallic nickel zinc phthalocyanine in 92.1% yield.
[0045] ICP analysis showed that the proportions of Ni and Zn in the total mass of the metal elements were 48.8% and 51.2%, respectively, which is consistent with the reaction.
[0046]
[0047] Example 9: 4-Isobutylphthalonitrile (4.5 mmol, 0.85 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with stannous chloride (0.5 mmol, 0.095 g) and nickel chloride (0.5 mmol, 0.065 g) in a molar ratio of 4.5:0.5:0.5. The reaction mixture was stirred at 190 °C for 8 hours under argon protection. After filtration, the mixture was washed with ethanol and dilute hydrochloric acid and dried to give isobutylbimetallic phthalocyanine nickel in 92.1% yield.
[0048] ICP analysis revealed that the proportions of Ni and Sn in the total mass of the contained metal elements were 33.9% and 66.1%, respectively, which is consistent with the reaction.
[0049]
[0050] Example 10: 2-Isopropylphthalonitrile (4.5 mmol, 0.77 g) was dissolved in triethylene glycol dimethyl ether (50 mL) with stannous chloride (0.5 mmol, 0.095 g) and copper nitrate (0.5 mmol, 0.094 g) in a molar ratio of 4.5:0.5:0.5. The reaction mixture was stirred at 205 °C for 7 hours under argon protection. After filtration, the mixture was washed with ethanol and dilute hydrochloric acid and dried to give isopropyl bimetallic tin phthalocyanine in copper, with a yield of 88.2%.
[0051] ICP analysis revealed that Cu comprised 35.4% and Sn comprised 64.6% of the total mass of the metal elements, consistent with the reaction.
[0052]
[0053] Example 11: Catalyst application: 1.20 g of isobutyl bimetallic phthalocyanine tin-nickel catalyst was directly dissolved in a 100 mL formic acid aqueous solution (85% by mass). After thorough mixing, the solution was transferred to a 500 mL high-pressure reactor and reacted at 268 °C and 3.5 MPa for 5 hours under a hydrogen atmosphere. After the reaction, product analysis showed a methanol selectivity of 84% and a formic acid conversion rate of 89%.
[0054]
[0055] Example 12: Catalyst application: 2.00 g of butoxybimetallic phthalocyanine ruthenium-tin catalyst was directly dissolved in an aqueous butyric acid solution (8% by mass, 100 mL). After thorough mixing, the solution was transferred to a 500 mL high-pressure reactor and reacted at 268 °C and 3.5 MPa for 5 hours under a hydrogen atmosphere. After the reaction, product analysis showed a butanol selectivity of 71% and a butyric acid conversion rate of 83%.
[0056]
[0057] Example 13: Catalyst application: 1.80 g of tert-butyl bimetallic phthalocyanine zinc-tin catalyst was directly dissolved in an aqueous acetic acid solution (10% by mass, 100 mL). After thorough mixing, the solution was transferred to a 500 mL high-pressure reactor and reacted at 252 °C and 4.5 MPa for 6 hours under a hydrogen atmosphere. After the reaction, product analysis showed an ethanol selectivity of 87% and an acetic acid conversion rate of 81%.
[0058] Example 14: Catalyst application: 1.50 g of 2-isopropylbimetallic copper-tin phthalocyanine catalyst was directly dissolved in a 15% (w / v) butyric acid aqueous solution (100 mL). After thorough mixing, the solution was transferred to a 500 mL high-pressure reactor and reacted at 245 °C and 3.8 MPa for 5 hours under a hydrogen atmosphere. After the reaction, product analysis showed a butanol selectivity of 80% and a butyric acid conversion rate of 75%.
[0059] Comparative Example 1 of Example 12: Catalyst application: 2.00 g of butoxyphthalocyanine ruthenium catalyst was directly dissolved in an aqueous butyric acid solution (8% by mass, 100 mL). After thorough mixing, the solution was transferred to a 500 mL high-pressure reactor and reacted at 268 °C and 3.5 MPa for 5 hours under a hydrogen atmosphere. After the reaction, product analysis showed a butanol selectivity of 30% and a butyric acid conversion rate of 55%.
[0060] Comparative Example 2 of Example 12: Catalyst application: 2.00 g of butoxytin phthalocyanine catalyst was directly dissolved in an aqueous butyric acid solution (8% by mass, 100 mL). After thorough mixing, the solution was transferred to a 500 mL high-pressure reactor and reacted at 268 °C and 3.5 MPa for 5 hours under a hydrogen atmosphere. After the reaction, product analysis showed a butanol selectivity of 22% and a butyric acid conversion rate of 35%.
[0061] Comparative Example 3 of Example 12: Catalyst application: 2.00 g of butoxyphthalocyanine zinc tin catalyst was directly dissolved in an aqueous butyric acid solution (8% by mass, 100 mL). After thorough mixing, the solution was transferred to a 500 mL high-pressure reactor and reacted at 268 °C and 3.5 MPa for 5 hours under a hydrogen atmosphere. After the reaction, product analysis showed a butanol selectivity of 63% and a butyric acid conversion rate of 75%.
[0062] Comparative Example 4 of Example 12: Catalyst application: 2.00 g of an amino-bimetallic phthalocyanine ruthenium-tin catalyst was directly dissolved in a butyric acid aqueous solution (8% by mass, 100 mL). After thorough mixing, the solution was transferred to a 500 mL high-pressure reactor and reacted at 268 °C and 3.5 MPa for 5 hours under a hydrogen atmosphere. After the reaction, product analysis showed a butanol selectivity of 45% and a butyric acid conversion rate of 54%.
[0063] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications may be made without departing from the technical solutions described in the claims.
Claims
1. A bimetallic phthalocyanine catalyst, characterized in that, The catalyst comprises a bimetallic phthalocyanine compound with the following general structural formula: ， In the formula, M is a metallic element selected from at least two of transition metals and tin; R1~R 16 Each is independently selected from H and at least one of the following groups: C3-C6 alkyl, C1-C6 alkoxy.
2. The bimetallic phthalocyanine catalyst according to claim 1, characterized in that, In the formula, M is selected from two of copper, ruthenium, zinc, nickel, palladium, iron, and tin, and the mass of any one of the metal elements accounts for 30%-70% of the total mass of the metal elements.
3. The bimetallic phthalocyanine catalyst according to claim 1, characterized in that, In the formula, R1~R 16 Each is independently selected from H and at least one of the following groups: isopropyl, n-butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, butoxy.
4. A method for preparing the bimetallic phthalocyanine catalyst according to any one of claims 1-3, characterized in that, Bimetallic phthalocyanine compounds are prepared by reacting phthalonitrile derivatives with metal salts containing metal element M, wherein metal element M is selected from at least two transition metals and tin.
5. The method for preparing a bimetallic phthalocyanine catalyst according to claim 4, characterized in that, In phthalonitrile derivatives, the substituents on the benzene ring are selected from hydrogen and at least one of the following groups: C3-C6 alkyl, C1-C6 alkoxy; Alternatively, the substituents on the benzene ring in the phthalonitrile derivative are selected from any one of isopropyl, n-butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, butoxy, and hydrogen.
6. The method for preparing a bimetallic phthalocyanine catalyst according to claim 4, characterized in that, The metal salt is selected from at least one of the chloride, sulfate, carbonate, nitrate, and acetate salts corresponding to the metal element M; Alternatively, the metal salt is selected from at least two of the following: stannous chloride, copper sulfate, copper carbonate, copper nitrate, ferric sulfate, zinc carbonate, zinc nitrate, ferric acetate, tin sulfate, nickel nitrate, nickel sulfate, nickel chloride, zinc chloride, tin chloride, palladium acetate, ruthenium chloride, and copper chloride. And / or, the metal salt comprises a salt of two metals, wherein the molar ratio of the two metal salts is 1:1 to 2:1 based on the metal elements.
7. The method for preparing a bimetallic phthalocyanine catalyst according to claim 4, characterized in that, In the reaction, the molar ratio of the phthalonitrile derivative to the metal salt is 4:1 to 6:1; And / or, the reaction temperature is 150-250℃, and the reaction time is not less than 4 hours; And / or, the reaction is carried out in an organic solvent.
8. The method for preparing a bimetallic phthalocyanine catalyst according to claim 7, characterized in that, In the reaction, the molar ratio of the phthalonitrile derivative to the metal salt is 4.5:1 to 5.5:1; And / or, the reaction temperature is 170-220℃, and the reaction time is not less than 4-12h; And / or, the organic solvent is selected from at least one of N,N-dimethylformamide and triethylene glycol dimethyl ether.
9. The application of a bimetallic phthalocyanine catalyst as described in any one of claims 1-3 in the fields of catalysts and chemical reactions.
10. The application according to claim 9, characterized in that, The chemical reactions mentioned include the reaction of acid hydrogenation to produce alcohol.