A method for preparing a tandem olefin hydroformylation-hydrogenation catalyst and its use

Abstract

The application discloses a preparation method of a bimetallic catalyst for olefin tandem hydroformylation-hydrogenation and application thereof. First, a cross-linked polymer (PCl) is prepared through Friedel-Crafts reaction by taking triphenylphosphine and 1,3-bis(diphenylphosphino)propane as raw materials; then, PCl is fully adsorbed with RhCl3 and RuCl3 to prepare PCl-Rh-Ru powder, and the PCl-Rh-Ru powder is reduced in a hydrogen atmosphere for 3 hours to prepare a RhRu@m-PC catalyst. In the RhRu@m-PC catalyst, Rh and Ru nanoparticles are highly dispersed in the pores of the carrier, which can effectively prevent the loss of metal active sites. In the olefin tandem hydroformylation-hydrogenation reaction, the conversion rate of the olefin catalyzed by the RhRu@m-PC catalyst is up to 99%, and the yield of alcohol is up to 97%. In the method, the preparation method of the RhRu@m-PC catalyst is simple, the ultrafine metal nanoparticles of the active sites are highly dispersed and embedded in the pores of the phosphine-doped carbon, the RhRu@m-PC catalyst can maintain high catalytic activity and stability in the olefin tandem hydroformylation-hydrogenation reaction, the RhRu@m-PC catalyst still maintains high activity after being recycled for five times, and the RhRu@m-PC catalyst is easy to be industrialized.

Description

Technical Field

[0001] This invention relates to the field of fine chemical technology, specifically to a bifunctional catalyst for a tandem hydroformylation-hydrogenation reaction, its preparation method, and its application in the one-step synthesis of alcohols. Background Technology

[0002] The hydroformylation of olefins is a crucial industrial process for the direct synthesis of aldehydes from olefins, CO, and H₂. Since its discovery by Otto Roelen in 1938, it has become a model for large-scale industrial applications of homogeneous catalysis (Angew. Chem. Int. Ed., 2012, 51, 2178-2182). This process produces over 20 million tons of aldehydes globally annually, and its products are key intermediates in the preparation of approximately 50 classes of high-value-added chemicals (such as plasticizers, surfactants, and solvents) (Chem. Rev., 2012, 112, 5675-5732). Aldehydes can be further hydrogenated to yield alcohols (such as C7-C14 alcohols), which are core raw materials for plasticizers and detergents, and market demand continues to grow (Appl. Catal. A, Gen., 2021, 623, 118266).

[0003] Traditional industrial alcohol synthesis typically employs a stepwise process: first, olefin hydroformylation is performed to produce aldehydes; after separating and purifying the aldehyde intermediate, catalytic hydrogenation is then carried out to produce alcohols. This process is lengthy, requires significant equipment investment, and is energy-intensive; furthermore, the intermediate separation and purification steps significantly increase production costs (Appl. Homogeneous Catal. Organomet. Compd., 2002, 1, 31-36). To overcome these drawbacks, a tandem process integrating hydroformylation and hydrogenation (reductive hydroformylation) has attracted considerable attention; this one-step technology achieves 100% atom economy, avoids intermediate separation, and is expected to significantly reduce investment and operating costs. However, the core challenge in achieving efficient tandem catalysis lies in developing bifunctional catalytic systems that combine high activity, high selectivity, and excellent stability. An ideal catalyst needs to simultaneously activate both olefin hydroformylation and aldehyde hydrogenation reactions in a syngas atmosphere while maintaining long-term structural stability (Chem. Rev., 2012, 112, 5675-5732). While homogeneous catalytic systems offer tunable activity and selectivity, they present challenges in catalyst separation and recovery. Heterogeneous catalytic strategies, though beneficial for separation, often face issues such as insufficient stability of active sites, mass transfer limitations, and difficulties in matching reaction kinetics. Specifically, existing catalytic systems mainly suffer from the following limitations: 1) Stability issues: Under syngas reaction conditions, metal active centers are prone to carbonylation and loss, leading to rapid catalyst deactivation (Chem. Eur. J., 2019, 25, 5534-5538); 2) Balancing activity and selectivity challenges: Noble metal (e.g., Rh, Ru)-based catalysts exhibit high hydroformylation activity, but their hydrogenation selectivity requires precise control; non-noble metal (e.g., Co) systems have lower costs, but demanding reaction conditions and more challenging selectivity control; 3) Insufficient structural and cycling stability: Most reported catalysts show significant activity decline during recycling, and their preparation cost, lifespan, and regeneration performance do not yet meet industrial requirements.

[0004] In recent years, catalysis researchers have explored various improvement strategies, such as using atomically dispersed metal catalysts to maximize atom utilization (Sci. China Chem., 2024, 67, 3706-3711), or using porous materials (such as MOFs, COFs, and POPs) as supports to precisely construct and stabilize active sites (ACS Catal., 2024, 14, 4593-4600). Although these new ideas (such as microenvironment regulation, bimetallic synergy, and nanoreactor confined catalysis) have shown potential (Angew. Chem. Int. Ed., 2025, e202424144), how to develop heterogeneous catalytic systems with high activity, high straight-chain alcohol selectivity, excellent long-term stability, and easy large-scale preparation without relying on expensive ligands remains a key bottleneck restricting the industrial application of this technology. Therefore, there is an urgent need to develop a novel, efficient, stable, and easily separable and recyclable multiphase bifunctional catalytic system to solve the problems of poor metal stability, low reaction step coupling efficiency, insufficient selectivity control, and poor cycle performance in existing technologies, thereby promoting the practical industrial application of the tandem hydroformylation-hydrogenation one-step alcohol synthesis technology. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method for preparing a phosphine-doped porous polymer-supported Rh and Ru bimetallic catalyst; and using the prepared catalyst, a method for synthesizing alcohol compounds by catalytic hydroformylation followed by hydrogenation from olefins is provided (taking styrene catalytic hydroformylation-hydrogenation as an example, see the following formula).

[0006]

[0007] The following technical solution is adopted to solve the technical problem of the present invention:

[0008] A method for preparing an olefin tandem hydroformylation-hydrogenation catalyst and its application are disclosed. The specific method for preparing a phosphine-doped porous polymer-supported Rh and Ru bimetallic catalyst is as follows: First, using 1,3-bis(diphenylphosphine)propane, triphenylphosphine, and dimethoxymethane as raw materials, a crosslinked polymer (PCl) is prepared via a Friedel-Crafts reaction. Next, a certain amount of PCl is added to a methanol solution containing RhCl3 and RuCl3, and stirred at room temperature to allow for full adsorption. The solvent is removed by rotary evaporation to obtain PCl-Rh-Ru powder. Then, the obtained PCl-Rh-Ru powder is placed in a tube furnace and heated to 200-300℃ under a hydrogen atmosphere for 3 hours, followed by cooling to room temperature and purging with an inert gas for 1 hour to obtain the RhRu@m-PC-x catalyst (x represents the reduction temperature).

[0009] The precursor material used in the prepared RhRu@m-PC-200 catalyst is PCl, which is prepared by the Friedel-Crafts reaction. This precursor material has abundant micro-mesoporous structures and phosphine coordination sites for triphenylphosphine and 1,3-bis(diphenylphosphino)propane, enabling efficient adsorption and coordination of Rh. 3+ With Ru 3+ The RhRu@m-PC-200 catalyst was then prepared.

[0010] In the preparation method of the RhRu@m-PC-200 catalyst, PCl is used as a precursor material, and an m-PC support with a large specific surface area, excellent stability, and hierarchical porous structure can be derived by reduction in a hydrogen atmosphere; the specific surface area of ​​the m-PC support is 426.4 m². 2 ·g -1 The average pore size is 11.9 nm.

[0011] In the preparation method of the RhRu@m-PC-200 catalyst, the reducing atmosphere temperature is 200℃, and the reducing atmosphere is V. H2 V Ar =1:9, reducing gas flow rate is 20mL / min, heating rate is 2℃ / min.

[0012] In the preparation method of the RhRu@m-PC-200 catalyst, the metal nanoparticles are highly dispersed and fixed inside the pores, effectively preventing the loss of metal active sites.

[0013] In the prepared RhRu@m-PC-200 catalyst, the mass ratio of Rh to Ru to the support is Rh:Ru:m-PC = 0.01:0.03:1.

[0014] The application of the RhRu@m-PC-200 catalyst in the tandem hydroformylation-hydrogenation reaction of olefins, taking styrene as an example, is as follows: A certain amount of RhRu@m-PC-200 catalyst and styrene are added to a high-pressure reactor, and a high-pressure CO and H2 mixture with a molar ratio of 1:1 is introduced into the high-pressure reactor. The reactor temperature is set, and after a certain reaction time, heating is stopped. After cooling to room temperature, a certain amount of pure hydrogen is introduced, and then the reaction is carried out at a certain temperature for a period of time. The reaction progress is analyzed by gas chromatography. The conversion rate of styrene is as high as 99%, and the yield of alcohols is as high as 97%.

[0015] The gas pressure for the olefin tandem hydroformylation-hydrogenation reaction is 1.0-2.0 MPa, the reaction temperature is 80-120℃, and the reaction time is 8-14 hours.

[0016] The RhRu@m-PC-200 catalyst can be reused up to 5 times for the olefin tandem hydroformylation-hydrogenation reaction, while still maintaining stable catalytic activity.

[0017] Advantages of this invention: 1. The phosphine-doped porous polymer-supported Rh and Ru bimetallic catalyst is mainly prepared using simple impregnation adsorption and calcination reduction methods. The catalyst preparation method is simple, the conditions are mild, and the catalyst is easy to scale up for production. 2. In the RhRu@m-PC-200 catalyst, ultrafine metal nanoparticles are uniformly dispersed within the porous carrier channels, resulting in excellent catalyst stability. It retains high activity even after five reuses. 3. The RhRu@m-PC-200 catalyst provided in this invention exhibits high olefin conversion and alcohol yield in the tandem hydroformylation-hydrogenation reaction of olefins, with excellent regioselectivity. The ratio of branched alcohol to straight-chain alcohol products can reach over 15:1. Furthermore, the reaction operation is simple, easy to control, and readily applicable for industrial application and scale-up production. 4. No catalyst replacement is required; olefins can be converted to alcohols in a one-pot, two-step process, significantly reducing production costs in practical applications. Attached Figure Description

[0018] Figure 1 This is a scanning electron microscope image of the RhRu@m-PC-200 catalyst prepared in Example 1 of the present invention.

[0019] Figure 2 This is a diagram illustrating the effect of catalyst reuse in the hydroformylation reaction of styrene catalyzed by the RhRu@m-PC-200 catalyst in Example 1 of this invention.

[0020] Figure 3 The XRD patterns of RhRu@m-PC-200, RhRu@m-PC-300, Ru@m-PC-200, and Rh@m-PC-200 in Embodiment 1 of the present invention are shown.

[0021] Figure 4 This is the thermogravimetric analysis spectrum of RhRu@m-PC in Example 1 of the present invention.

[0022] Figure 5 The image shows the H2-TPD (hydrogen temperature-programmed desorption) spectrum of RhRu@m-PC in Example 1 of this invention.

[0023] Figure 6 This is a spectrum of H2-TPR (hydrogen temperature programmed reduction) of RhRu@m-PC in Example 1 of the present invention. Detailed Implementation

[0024] Example 1

[0025] A method for preparing an olefin tandem hydroformylation-hydrogenation catalyst and its application are disclosed. The specific operation method is as follows: 5.25 g of triphenylphosphine, 4.12 g of 1,3-bis(diphenylphosphino)propane, 15.2 mL of dimethoxymethane, 20 mL of 1,2-dichloroethane, and 18 g of anhydrous ferric chloride are added to a round-bottom flask and dissolved uniformly. The mixture is then stirred continuously at 45 °C for 6 h, and the temperature is raised to 80 °C for 66 h. After that, the mixture is centrifuged and washed until the solution turns pale yellow, and then vacuum dried to obtain the supported PCl. 500 mg of PCl support was dispersed in 100 mL of methanol solution, sonicated for 0.5 h and stirred for 2 h to ensure uniform dispersion. 12.8 mg of rhodium chloride trihydrate and 83.2 mg of ruthenium chloride hydrate were dissolved in 10 mg of methanol and slowly added dropwise to the support suspension. The mixture was stirred overnight to allow for full adsorption. The methanol solvent was removed by rotary evaporation. The resulting solid powder was then placed in a tube furnace and heated to 200 °C at a rate of 2 °C / min. It was reduced for 2 h under an H2 / Ar atmosphere to obtain the RhRu@m-PC-200 catalyst, which contained 1.0% Rh and 3% Ru.

[0026] Example 2

[0027] A method for preparing an olefin tandem hydroformylation-hydrogenation catalyst and its application are disclosed. The specific method is as follows: 40 mg of RhRu@m-PC-200 catalyst from Example 1 and 100 μL of styrene are added to a 10 mL high-pressure reactor. A CO / H2 mixture (V:V = 1:1) at 2 MPa is introduced, and the reaction is carried out at 100 °C for 8 h. After cooling, 1 MPa of H2 is introduced, and the reaction is carried out at 120 °C for 14 h. Gas chromatography analysis shows that the conversion rate of styrene is 99%, and the selectivity of alcohol is 97%.

[0028] Examples 3-9

[0029] A method for preparing an olefin tandem hydroformylation-hydrogenation catalyst and its application are disclosed. The specific method is as follows: 40 mg of RhRu@m-PC-200 catalyst and 100 mg of olefin from Example 1 are added to a 10 mL high-pressure reactor, and a CO / H2 mixture (V:V = 1:1) at 2 MPa is introduced. The reaction is carried out at 100 °C for 8 h, cooled, and then 1 MPa of H2 is introduced. The reaction is carried out at 120 °C for 14 h. The olefin conversion rate and the selectivity of the product alcohol are shown in Table 1 below.

[0030] Table 1. Results of RhRu@m-PC-200 catalyzed tandem hydroformylation-hydrogenation reactions of different olefins.

[0031]

[0032]

[0033] Example 10

[0034] A method for preparing an olefin tandem hydroformylation-hydrogenation catalyst and its application are disclosed. The specific method is as follows: 40 mg of RhRu@m-PC-200 catalyst from Example 1 and 100 μL of styrene are added to a 10 mL high-pressure reactor. A CO / H2 mixture (V:V = 1:1) at 2 MPa is introduced, and the reaction is carried out at 100 °C for 8 h. After cooling, 1 MPa of H2 is introduced, and the reaction is carried out at 120 °C for 14 h. Gas chromatography analysis shows that the conversion rate of styrene is higher than 90% after 5 reuses of the RhRu@m-PC-200 catalyst, and the selectivity of alcohol is higher than 80% in all cases.

Claims

1. A method for preparing a tandem olefin hydroformylation-hydrogenation catalyst and its application, characterized in that: First, a cross-linked polymer PCl was prepared by Friedel-Crafts reaction using triphenylphosphine, 1,3-bis(diphenylphosphine)propane, and dimethoxymethane as raw materials. Then, PCl was added to a methanol solution containing RhCl3 and RuCl3, and the solvent was removed after adsorption to obtain PCl-Rh-Ru powder. Subsequently, it was reduced in a hydrogen atmosphere at 200-300℃ to obtain the phosphine-doped porous polymer-supported Rh and Ru bimetallic catalyst RhRu@m-PC-x (where x represents the reduction temperature).

2. The preparation method and application of the tandem olefin hydroformylation-hydrogenation catalyst according to claim 1, characterized in that: The PCl support was prepared via a Friedel-Crafts reaction and possesses a micro-mesoporous structure and phosphine coordination sites, enabling it to adsorb and coordinate Rh. 3+ and Ru 3+ .

3. The preparation method and application of the tandem olefin hydroformylation-hydrogenation catalyst according to claim 1, characterized in that: The mass ratio of Rh to Ru to the support in the RhRu@m-PC-200 catalyst is Rh:Ru:m-PC = 0.01:0.03:

1.

4. The preparation method and application of the tandem olefin hydroformylation-hydrogenation catalyst according to claim 1, characterized in that: In the reducing atmosphere, the temperature is 200-300℃, the volume ratio of hydrogen to argon is 1:9, the gas flow rate is 20mL / min, and the heating rate is 2℃ / min.

5. The preparation method and application of the tandem olefin hydroformylation-hydrogenation catalyst according to claim 1, characterized in that... In the RhRu@m-PC-200 catalyst, Rh and Ru nanoparticles are highly dispersed and fixed inside the pores of the PCl support.

6. The preparation method and application of the tandem olefin hydroformylation-hydrogenation catalyst according to claim 1, characterized in that: The RhRu@m-PC-200 catalyst and olefins were added to a high-pressure reactor. First, a CO / H2 mixture (volume ratio 1:1) at 1.0-2.0 MPa was introduced, and the reaction was carried out at 80-120℃ for 8-14 hours. Then, the reactor was cooled, pure hydrogen was introduced, and the reaction was carried out at 120℃ for 14 hours. The conversion rate of olefins was as high as 99%, and the yield of the product alcohol was as high as 97%.

7. The preparation method and application of a tandem olefin hydroformylation-hydrogenation catalyst according to claims 1 and 6, characterized in that... The RhRu@m-PC-200 catalyst can be reused 5 times, with a styrene conversion rate of over 90% and an alcohol selectivity of over 80%.

Images