Method for continuously synthesizing formic acid under mild condition by adopting fixed bed

Abstract

The invention provides a method for continuously synthesizing formic acid under mild conditions by adopting a fixed bed. According to the method, a proton response type porous organic iridium polymer obtained by weaving a proton response type iridium catalyst monomer through a Friedel-Crafts reaction catalyzed by ferric trichloride is used as a catalyst, and carbon dioxide hydrogenation reaction is catalyzed in a fixed bed reactor at the temperature of 30-120 DEG C and the pressure of 0.1-1.0 MPa to obtain formate. The mechanism for realizing the method is that the proton response type porous organic iridium polymer obtained by the Friedel-Crafts reaction can quickly form iridium hydrogen bonds under reaction conditions, and then a carbon dioxide insertion process is carried out to generate formate. Compared with the prior art, the method provided by the invention can efficiently and continuously produce formic acid under mild conditions, and is a green, low-carbon and safe formic acid synthesis method.

Description

Technical Field

[0001] The invention relates to the field of green chemical industry, and in particular to a technology for continuously synthesizing formic acid by using a porous organic iridium polymer catalyzed in a fixed bed under mild conditions. Technical Background

[0002] Formic acid is a basic organic chemical raw material with a wide range of uses. In the pesticide and pharmaceutical industries, formic acid is an important raw material for the synthesis of a variety of drug intermediates. In the chemical industry, it can be used to manufacture various formates and formates. In addition, it also plays an important role in the leather and rubber industries. Formic acid can also be used in many fields such as fabric processing, textile printing and dyeing, and metal surface treatment. In the energy field, formic acid is a very promising hydrogen carrier. Its volume and weight H2 capacity are 53g / L and 4.4wt% respectively, corresponding to 1.77kWh L -1 High energy density.

[0003] The direct hydrogenation of CO2 to produce formic acid has the advantage of high atom economy, and some patents have reported related technologies. Patent CN1593753 reports the reaction performance of a functionalized SiO2-supported ruthenium + ligand catalyst, which can obtain a conversion number of 1384 at 85°C and 16MPa. Patent CN113292411A reports a perovskite catalyst for the process of hydrogenating carbon dioxide to produce formic acid, which can obtain a conversion number of 308.04 at 100°C and 2MPa. Patent CN117599857A reports a porous organic metal iridium polymer, which can obtain a conversion number of 1110800 at 150°C and 7MPa. Patent CN116808949B reports a carbon dioxide hydrogenation reaction device, using a palladium catalyst, and obtained a conversion number of 3537 at 80°C and 4MPa. In the reaction systems reported above, the carbon dioxide hydrogenation process often requires high temperature and high pressure conditions and is carried out in a high-pressure reactor, which is due to the insufficient activity of the catalyst. Continuous CO2 hydrogenation in a fixed bed is more suitable for industrial production due to its convenient operation, safety and high efficiency. If the catalyst activity is not high, hydrogen activation and carbon dioxide insertion processes cannot be achieved quickly under the low residence time conditions of the fixed bed reactor, and it is difficult to obtain good conversion results. This is also the reason why the currently reported technologies rarely achieve efficient CO2 hydrogenation to formic acid in a fixed bed. Summary of the invention

[0004] In view of the above problems, the present invention designs and synthesizes a type of highly active proton-responsive porous organic polymerized iridium heterogeneous catalyst and develops a continuous flow CO2 hydrogenation process for preparing formic acid under mild conditions. The porous organic polymerized iridium heterogeneous catalyst is prepared by directly weaving and polymerizing the proton-responsive iridium catalyst monomer using the Friedel-Crafts reaction catalyzed by FeCl3 and benzene and dimethoxymethane. This type of catalyst can efficiently catalyze the CO2 hydrogenation reaction under mild conditions (30-120°C, 0.1-1.0MPa), providing a new and efficient method for preparing formate by CO2 hydrogenation.

[0005] The preparation process of the proton-responsive porous organic polymerization iridium heterogeneous catalyst is as follows:

[0006]

[0008] The mechanism by which the present invention is achieved is that the proton-responsive porous organic polymerized iridium catalyst can rapidly activate hydrogen to form an Ir-H bond under reaction conditions, and then implement a carbon dioxide insertion process to generate formate. The high activity of such proton-responsive porous organic polymerized iridium catalyst is sufficient to support an efficient formic acid production process in a fixed bed reactor.

[0009] The above-mentioned method of continuously synthesizing formic acid under mild conditions using a fixed bed is a further feasible scheme, and its steps include: preparing a porous organic polymerized iridium heterogeneous catalyst using proton-responsive iridium catalyst monomer, benzene, ferric chloride, and dimethoxymethane as raw materials, and catalyzing the hydrogenation of carbon dioxide to prepare formate in a fixed bed reactor using water as a solvent.

[0010] The method for preparing formate by hydrogenating CO2 in a fixed bed reactor is preferably characterized in that the proton-responsive porous organic iridium heterogeneous catalyst has the following structure:

[0011]

[0012] The catalyst synthesis method is preferably characterized in that the molar ratio of the proton-responsive iridium catalyst monomer, benzene, ferric chloride and dimethoxymethane is 1:1:1:1-1:20:40:40.

[0013] The catalyst synthesis method is preferably characterized in that the monomer for preparing the proton-responsive iridium porous organic iridium polymer comprises the following structure:

[0014]

[0015]

[0016] The catalyst synthesis method is preferably characterized in that the reaction temperature is 60°C-120°C and the reaction time is 12-48h when preparing the catalyst.

[0017] The method for preparing formate by hydrogenating CO2 in a fixed bed reactor is preferably characterized in that the amount of catalyst used is 0.0001-0.01 mmol based on the molar amount of iridium contained.

[0018] The method for preparing formate by hydrogenating CO2 in a fixed bed reactor is preferably characterized in that the reaction temperature is 30°C-120°C.

[0019] The method for preparing formate by hydrogenating CO2 in a fixed bed reactor is preferably characterized in that the reaction pressure is 0.1-1.0 MPa.

[0020] The method for preparing formate by hydrogenating CO2 in a fixed bed reactor is preferably characterized in that the liquid hourly space velocity is 0.1-10h -1 .

[0021] The method for preparing formate by hydrogenating CO2 in a fixed bed reactor is preferably characterized in that the gas hourly space velocity is 10-2000h -1 .

[0022] The method for preparing formate by hydrogenating CO2 in a fixed bed reactor is preferably characterized in that potassium hydroxide, potassium bicarbonate, potassium carbonate, sodium hydroxide, sodium bicarbonate, sodium carbonate, triethylamine, DBN and DBU are used as bases. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 This is a scanning electron microscope image of the porous organic polymer iridium catalyst of the present invention.

[0024] Attached Figure 2 This is the EDS-mapping surface scanning spectrum of the porous organic polymerization iridium catalyst of the present invention

[0025] Attached Figure 3 Schematic diagram of the device for continuously synthesizing formic acid under mild conditions of the present invention Specific implementation plan

[0026] The embodiments of the present invention will be described in detail below in conjunction with examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. Without departing from the scope of the preceding and following purposes, variations are included within the technical scope of the present invention.

[0027] Example 1

[0028] Cp*Ir-Py-Im-OH complex (0.1mmol, 63mg) and benzene (1mmol, 78mg) were dissolved in 5mL 1,2-dichloroethane. After stirring at room temperature for five minutes, anhydrous FeCl3 (2.0mmol, 324mg) and dimethoxymethane (2.0mmol, 152mg) were added. The resulting mixture was heated to 85°C and stirred for 24h under a nitrogen atmosphere. After cooling to room temperature, the precipitate was washed with methanol, distilled water, difluoromethane and acetone in sequence. It was further purified by Soxhlet extraction with methanol for 48h and vacuum dried at 60°C for 24h to obtain dark brown powder KAPs-Cp*Ir-Py-Im-OH (yield 53%).

[0029] Example 2

[0030] Cp*Ir-Py-Im complex (0.1mmol, 61mg) and benzene (1mmol, 78mg) were dissolved in 5mL 1,2-difluoroethane. After stirring at room temperature for five minutes, anhydrous FeCl3 (2.0mmol, 324mg) and dimethoxymethane (2.0mmol, 152mg) were added. The resulting mixture was heated to 85°C and stirred for 24h under a nitrogen atmosphere. After cooling to room temperature, the precipitate was washed with methanol, distilled water, difluoromethane and acetone in sequence. It was further purified by methanol Soxhlet extraction for 48h and vacuum dried at 60°C for 24h to obtain dark brown powder KAPs-Cp*Ir-Py-Im (yield 57%).

[0031] Example 3

[0032] Cp*Ir-BPY-OH complex (0.1mmol, 66mg) and benzene (1mmol, 78mg) were dissolved in 5mL 1,2-difluoroethane. After stirring for five minutes, anhydrous FeCl3 (2.0mmol, 324mg) and dimethoxymethane (2.0mmol, 152mg) were added. The resulting mixture was heated to 85°C and stirred for 24h under a nitrogen atmosphere. After cooling to room temperature, the precipitate was washed with methanol, distilled water, difluoromethane and acetone in sequence. It was further purified by Soxhlet extraction with methanol for 48h and vacuum dried at 60°C for 24h to obtain dark brown powder KAPs-Cp*Ir-BPY-OH (yield 66%).

[0033] Example 4

[0034] Cp*Ir-BPY complex (0.1mmol, 64mg) and benzene (1mmol, 78mg) were dissolved in 5mL 1,2-difluoroethane. After stirring for five minutes, anhydrous FeCl3 (2.0mmol, 324mg) and dimethoxymethane (2.0mmol, 152mg) were added. The resulting mixture was heated to 85°C and stirred for 24h under a nitrogen atmosphere. After cooling to room temperature, the precipitate was washed with methanol, distilled water, difluoromethane and acetone in sequence. It was further purified by Soxhlet extraction with methanol for 48h and vacuum dried at 60°C for 24h to obtain dark brown powder KAPs-Cp*Ir-BPY (yield 66%).

[0035] Example 5

[0036] Cp*Ir-N-Ph-OH complex (0.1mmol, 68mg) and benzene (1mmol, 78mg) were dissolved in 5mL 1,2-dichloroethane. After stirring for five minutes, anhydrous FeCl3 (2.0mmol, 324mg) and dimethoxymethane (2.0mmol, 152mg) were added. The resulting mixture was heated to 85°C and stirred for 24h under a nitrogen atmosphere. After cooling to room temperature, the precipitate was washed with methanol, distilled water, difluoromethane and acetone in sequence. It was further purified by Soxhlet extraction with methanol for 48h and vacuum dried at 60°C for 24h to obtain dark brown powder KAPs-Cp*Ir-N-Ph-OH (yield 81%).

[0037] Example 6

[0038] Cp*Ir-N-Ph complex (0.1mmol, 67mg) and benzene (1mmol, 78mg) were dissolved in 5mL 1,2-difluoroethane. After stirring for five minutes, anhydrous FeCl3 (2.0mmol, 324mg) and dimethoxymethane (2.0mmol, 152mg) were added. The resulting mixture was heated to 85°C and stirred for 24h under a nitrogen atmosphere. After cooling to room temperature, the precipitate was washed with methanol, distilled water, difluoromethane and acetone in sequence. It was further purified by methanol Soxhlet extraction for 48h and vacuum dried at 60°C for 24h to obtain dark brown powder KAPs-Cp*Ir-N-Ph (yield 77%).

[0039] Example 7

[0040] The continuous reaction device for preparing formic acid by hydrogenating carbon dioxide comprises: a carbon dioxide / hydrogen mixed gas cylinder, a pressure gauge, a gas mass flow meter, a one-way check valve, an alkali aqueous solution storage tank, a high-pressure liquid horizontal flow pump, a gas-liquid mixer, a heating device, a fixed bed reaction tube, and a back pressure regulator.

[0041] The outlet of the carbon dioxide / hydrogen mixed gas path is connected to the inlet of the gas-liquid mixer; and the outlet of the alkaline aqueous solution liquid path is connected to the inlet of the gas-liquid mixer.

[0042] The outlet of the gas-liquid mixer is connected to the inlet of the fixed bed reaction tube; and the outlet of the fixed bed reaction tube is connected to the back pressure valve.

[0043] The alkali aqueous solution storage tank is preheated by a heating device; and the fixed bed reaction tube is heated by a heating device.

[0044] The diameter of the fixed bed reaction tube is 6 mm×4 mm and the length is 66 mm.

[0045] The use of the device:

[0046] 1. The proton-responsive porous organic polymerization iridium catalyst was fully mixed with 100 mg of quartz sand and then filled into the fixed bed reaction tube. Both ends were sealed with an appropriate amount of quartz wool to prevent the catalyst and quartz sand particles from overflowing.

[0047] 2. Preset the temperature of the heating device, preheat the alkali solution in the heating device, maintain the flow rate of the gas mass flow meter, and the flow rate of the high-pressure liquid advection pump is stable. Open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to the reaction pressure after stable operation at normal pressure for 1 hour.

[0048] 3. Take samples every hour, add isopropanol as internal standard, take out 100 μL of reaction solution, mix with 400 μL D2O, and perform 1 The amount of formate was determined by H NMR analysis, and the result was averaged twice.

[0049] The formic acid production efficiency and TOF were calculated according to the following formula.

[0050]

[0051]

[0052] Among them, formic acid production efficiency refers to the amount of formic acid produced per gram of iridium per unit time. TOF refers to the number of substrate conversions per mole of catalyst per unit active center per unit time. n1 refers to the amount of formate produced, n cat Indicates the amount of iridium-containing substances in the catalyst used. The amount of formate is calibrated by H-NMR, with isopropanol as the internal standard and deuterated water as the lock field.

[0053] Example 8

[0054] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-Py-Im-OH is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, and the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 H NMR analysis was used to determine the amount of formate. Under these conditions, the formic acid production efficiency was 1229 mmol FA / g 金属 / h, TOF is 238h -1 .

[0055] Example 9

[0056] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-Py-Im is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, the gas mass flow meter flow rate is kept stable, the gas hourly space velocity is 900h-1, the high-pressure liquid advection pump flow rate is kept stable, and the liquid hourly space velocity is 3.6h-1. -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 H NMR analysis was used to determine the amount of formate. Under these conditions, the formic acid production efficiency was 698 mmol FA / g 金属 / h, TOF is 135h -1 .

[0057] Example 10

[0058] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-BPY-OH is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, and the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 H NMR analysis was used to determine the amount of formate. Under this condition, the formic acid production efficiency was 1035 mmol FA / g 金属 / h, TOF is 200h -1 .

[0059] Embodiment 11

[0060] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-BPY is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, and the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 H NMR analysis was used to determine the amount of formate. Under these conditions, the formic acid production efficiency was 264 mmol FA / g 金属 / h, TOF is 51h -1 .

[0061] Example 12

[0062] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-N-Ph-OH is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 H NMR analysis was used to determine the amount of formate. Under these conditions, the formic acid production efficiency was 1444 mmol FA / g 金属 / h, TOF is 279h -1 .

[0063] Embodiment 13

[0064] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-N-Ph as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 H NMR analysis was used to determine the amount of formate. Under these conditions, the formic acid production efficiency was 919 mmol FA / g 金属 / h, TOF is 178h -1 .

[0065] Embodiment 14

[0066] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-N-Ph-OH is used as the catalyst, the catalyst dosage is 0.0001mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, and the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 H NMR analysis was used to determine the amount of formate. Under this condition, the formic acid production efficiency was 2368 mmol FA / g 金属 / h, TOF is 455h -1 .

[0067] Embodiment 15

[0068] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-N-Ph-OH is used as the catalyst, the catalyst dosage is 0.01mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 H NMR analysis was used to determine the amount of formate. Under these conditions, the formic acid production efficiency was 583 mmol FA / g 金属 / h, TOF is 112h -1 .

[0069] Example 16

[0070] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-N-Ph-OH is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the heating device is preset to different temperatures, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in a water bath, and the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 The amount of formate was determined by H NMR analysis. The results are as follows.

[0071] Temperature / ℃ <![CDATA[TOF / h -1 ]]> <![CDATA[Formic acid production efficiency / (mmol FA / g 金属 / h)]]> 30 82 425 50 279 1444 80 2013 10403 120 2645 13672

[0072] Embodiment 17

[0073] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-N-Ph-OH is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1 , open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to different pressures after running stably at normal pressure for 1 hour. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 The amount of formate was determined by H NMR analysis. The results are as follows.

[0074] Pressure / MPa <![CDATA[TOF / h -1 ]]> <![CDATA[Formic acid production efficiency / (mmol FA / g 金属 / h)]]> 0.1 190 980 0.4 315 1629 0.6 466 2409 0.8 627 3240 1.0 689 3562

[0075] Embodiment 18

[0076] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-N-Ph-OH is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, the gas mass flow meter flow rate is kept stable, the different gas hourly space velocities are adjusted, the high-pressure liquid horizontal flow pump flow rate is kept stable, the liquid hourly space velocity is 3.6h-1, the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder is opened to 1MPa, the back pressure valve is released, and the back pressure valve is adjusted to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, the reaction solution is sampled, 0.1g of isopropanol is added as an internal standard, 100μL of the reaction solution is taken out, mixed with 400μL of D2O, and carried out. 1 The amount of formate was determined by H NMR analysis. The results are as follows.

[0077] <![CDATA[Gas hourly space velocity / h -1 > <![CDATA[TOF / h -1 ]]> <![CDATA[Formic acid production efficiency / (mmol FA / g 金属 / h)]]> 10 390 2015 360 317 1638 720 290 1497 1080 261 1348 1440 202 1044 1800 164 848 2000 152 786

[0078] Embodiment 19

[0079] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-N-Ph-OH is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, the alkali used is potassium hydroxide, and the concentration is 1mol / L. The alkali solution is preheated in the water bath, the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high-pressure liquid advection pump flow rate stable, adjust different liquid hourly space speeds, open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 1.0MPa after 1 hour of stable operation at normal pressure. Sample the reaction solution 1 hour later, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 The amount of formate was determined by H NMR analysis. The results are as follows.

[0080] <![CDATA[Liquid hourly space velocity / h -1 > <![CDATA[TOF / h -1 ]]> <![CDATA[Formic acid production efficiency / (mmol FA / g 金属 / h)]]> 0.1 622 3216 1.8 416 2151 3.6 279 1443 5.4 117 603 7.2 43 222 9.0 16 82 10.0 9 46

[0081] Embodiment 20

[0082] The catalytic system used in the device disclosed in Example 7 is: KAPs-Cp*Ir-N-Ph-OH is used as the catalyst, the catalyst dosage is 0.0003mmol based on iridium, the water bath temperature is preset to 50°C, and different types of alkali are used with a concentration of 1mol / L. The alkali solution is preheated in the water bath, and the gas mass flow meter flow rate is kept stable, and the gas hourly space velocity is 900h -1 , keep the high pressure liquid flow pump flow rate stable, liquid hourly space velocity is 3.6h -1, open the hydrogen and carbon dioxide mixed gas (1 / 1) cylinder to 1MPa, loosen the back pressure valve, and adjust the back pressure valve to 0.4MPa after 1 hour of stable operation at normal pressure. After 1 hour, sample the reaction solution, add 0.1g isopropanol as an internal standard, take out 100μL of the reaction solution, mix it with 400μL D2O, and perform 1 The amount of formate was determined by H NMR analysis. The results are as follows.

[0083] <![CDATA[Liquid hourly space velocity / h -1 > <![CDATA[TOF / h -1 ]]> <![CDATA[Formic acid production efficiency / (mmol FA / g 金属 / h)]]> KOH 279 1443 <![CDATA[KHCO3]]> 241 1243 <![CDATA[K2CO3]]> 262 1352 NaOH 273 1411 <![CDATA[NaHCO3]]> 254 1315 <![CDATA[Na2CO3]]> 234 1207 DBU 162 839 TEA 147 758 DBN 109 563

Claims

1. A method for continuously synthesizing formic acid under mild conditions using a fixed bed, wherein a class of proton-responsive porous organic iridium polymers are used as catalysts to catalyze the hydrogenation of carbon dioxide to synthesize formate at 30-120°C and 0.1-1.0MPa pressure.

2. The method according to claim 1, Features The structure of the proton-responsive porous organic iridium polymer is as follows: 。 3. The method according to claim 1, Features The proton-responsive porous organic iridium polymer catalyst is prepared from proton-responsive iridium catalyst monomer, benzene, ferric chloride and dimethoxymethane as raw materials.

4. The method according to claim 3, Features The molar ratio of the proton-responsive iridium catalyst monomer, benzene, ferric chloride and dimethoxymethane is 1:1:1:1-1:20:40:

40.

5. The method according to claim 3, Features The proton-responsive iridium catalyst monomer includes the following structure: 。 6. The method according to claim 3, Features When preparing the catalyst, the reaction temperature is 60°C-120°C and the reaction time is 12-48h.

7. The method according to claim 1, Features The amount of catalyst used is 0.0001-0.01 mmol based on the molar amount of iridium contained.

8. The method according to claim 1, Features The reaction temperature is 30°C-120°C, and the reaction pressure is 0.1-1.0MPa.

9. The method according to claim 1, Features Liquid hourly space velocity is 0.1-10h -1 , gas hourly space velocity is 10-2000h -1 .

10. The method according to claim 1, Features Potassium hydroxide, potassium bicarbonate, potassium carbonate, sodium hydroxide, sodium bicarbonate, sodium carbonate, triethylamine, DBN and DBU were used as bases.

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