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CN-122013203-A - System, method and application for synthesizing acetic acid through directional conversion of carbon monoxide by photoelectrocatalysis

CN122013203ACN 122013203 ACN122013203 ACN 122013203ACN-122013203-A

Abstract

The invention relates to a system, a method and an application for synthesizing acetic acid by photoelectrocatalysis carbon monoxide directional conversion, wherein the system is a photoelectrocatalysis reaction system and comprises a cathode reaction tank and a photoelectrocatalysis component, wherein a cathode catalyst adopted by the cathode reaction tank is a copper-based catalyst which is directly supported on the surface of carbon paper, carbon monoxide reaction gas is introduced into the back surface of the carbon paper, the photoelectrocatalysis component comprises a light source and a quartz glass plate, visible light is used as an excitation light source, a cathode catalyst layer is directly irradiated through the quartz glass plate, the evolution path of a surface reaction intermediate is changed, and the directionally conversion of the carbon monoxide into the acetic acid is promoted. Compared with the prior art, the maximum current density of the invention exceeds 900mA/cm 2 , and the continuous operation of the invention for more than 270 hours still maintains excellent acetic acid selectivity and production efficiency, thus being a more efficient and stable reaction system.

Inventors

  • LI JUN
  • SUN NING
  • ZHAO YANAN

Assignees

  • 上海交通大学

Dates

Publication Date
20260512
Application Date
20241111

Claims (10)

  1. 1. The system is characterized by comprising a cathode-anode reaction tank and a light auxiliary component, wherein a cathode catalyst adopted by the cathode-anode reaction tank is a copper-based catalyst which is directly supported on the surface of carbon paper, carbon monoxide reaction gas is introduced into the back of the carbon paper, the light auxiliary component comprises a light source and a quartz glass plate, visible light is used as an excitation light source, a cathode catalyst layer is directly irradiated through the quartz glass plate, the evolution path of a surface reaction intermediate is changed, and the directional conversion of the carbon monoxide into the acetic acid is promoted.
  2. 2. The system for synthesizing acetic acid by photoelectrically catalyzing the directional conversion of carbon monoxide according to claim 1, wherein the electrolyte is 0.1-5 m KOH solution.
  3. 3. The system for synthesizing acetic acid by directionally converting carbon monoxide into photoelectric catalytic according to claim 1, wherein the light source adopted by the light auxiliary component is a single-wavelength LED light source, the adjustable range of optical power density is 0.5-3.5W/cm 2 , and the wavelength is 532nm.
  4. 4. The system for the direct conversion of carbon monoxide to acetic acid according to claim 1, wherein the reaction pressure is from 0.5 bar to 5bar.
  5. 5. The system for synthesizing acetic acid by directionally converting carbon monoxide into photoelectrocatalysis according to claim 1, wherein the copper-based catalyst is prepared by dissolving copper acetate in deionized water, adding NaOH, performing hydrothermal reaction for 2-5h at 100-300 ℃, cooling to room temperature, taking out, and vacuum drying to obtain copper oxide nano particles.
  6. 6. The system for synthesizing acetic acid by directionally converting carbon monoxide into photoelectrocatalysis of claim 1, wherein the copper-based catalyst is directly loaded on the surface of the carbon paper, copper oxide nano particles are mixed in Nafion solution, uniformly dispersed and then dripped on the surface of the carbon paper, and the loading amount of the copper oxide nano particles is 6-12mg/cm 2 .
  7. 7. The system for synthesizing acetic acid by directionally converting carbon monoxide into photoelectric catalytic action according to claim 1, wherein the cathode and anode reaction tanks are internally provided with an ion exchange membrane, an anode catalyst and a cathode catalyst, wherein the anode catalyst is arranged on the side of the ion exchange membrane and is perpendicular to the cathode catalyst, or the anode catalyst and the cathode catalyst are arranged on the two sides of the ion exchange membrane.
  8. 8. A method for synthesizing acetic acid by photoelectrocatalysis of directional conversion of carbon monoxide using the system of any one of claims 1 to 7, comprising the steps of: Inputting electrolyte into a cathode-anode reaction tank, introducing carbon monoxide into the back of a cathode catalyst, controlling the flow rate of the electrolyte to be 1-15mL/min, controlling the flow rate of carbon monoxide gas to be 2-50mL/min, and adding visible light for irradiation in the electrocatalytic reaction process by a 1bar manometer to promote the directional conversion of the carbon monoxide into acetic acid.
  9. 9. The method for synthesizing acetic acid by directionally converting carbon monoxide into photoelectrocatalysis according to claim 8, wherein the photoelectrocatalysis reaction condition comprises a current density of 50-1000 mA/cm 2 , a reaction area of 0.2-1 cm 2 , and the illumination condition comprises an adjustable optical power density range of 0.5-3.5W/cm 2 and a wavelength of 532nm.
  10. 10. Use of the system according to any one of claims 1-7 for the production of acetic acid by conversion of carbon monoxide.

Description

System, method and application for synthesizing acetic acid through directional conversion of carbon monoxide by photoelectrocatalysis Technical Field The invention belongs to the field of acid preparation by converting a carbon substrate, and particularly relates to a system, a method and application for synthesizing acetic acid by directionally converting carbon monoxide through photoelectrocatalysis. Background Acetic acid is an important commodity chemical with annual yields exceeding 1800 tens of thousands of tons and annual market values exceeding $100 billion. Current acetic acid production processes, typically using chemical synthesis or starch fermentation, require a multi-step process in which synthesis gas is thermocatalytically converted to methanol at 50-100bar and 500 ℃ and then methanol and CO are methyl carbonylated to form acetic acid, which originates from fossil fuels and produces 1.6 tons of carbon dioxide per ton of acetic acid produced. Direct synthesis of acetic acid from carbon dioxide (carbon monoxide) conversion using renewable electricity and water is one way to reduce carbon emissions in the chemical industry. Electrochemical systems driven by renewable electricity have been able to achieve the synthesis of acetic acid using CO 2 or CO and water as reagents. However, the current densities of the high selectivity electrocatalytic carbon monoxide reduction to acetic acid reported to date are all below 500mA/cm 2, and there are still performance barriers to achieving wide industrial applications. This is because as the current density increases, the effect of improving the active site for a particular intermediate is very little, resulting in a decrease in product selectivity at high current densities. Patent CN202111188530.X discloses an electrocatalyst for electrocatalytically reducing carbon monoxide to generate acetic acid and application thereof, wherein an electrocatalyst-copper-palladium alloy nanoparticle electrocatalyst for electrocatalytically reducing carbon monoxide to generate acetic acid is prepared, and then the electrocatalyst is used as a catalytic reaction cathode, potassium hydroxide electrolyte is adopted to electrocatalytically reduce carbon monoxide and selectively generate acetic acid. The catalyst can continuously and stably run for 500 hours in a membrane electrode device with the total current of 2.5A, and can keep higher Faraday efficiency of acetic acid. However, the technology can improve the selectivity of acetic acid to a certain extent only by regulating and controlling the adsorption energy of the intermediate through the modified catalyst, but the efficiency is difficult to break through further under the principle of Sabatier. This regulation of the catalyst active site for the preferred intermediate is random and limited in effect, resulting in lower practical bias current densities for acetic acid production and faradaic efficiencies below 80%. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a system, a method and application for synthesizing acetic acid by directionally converting carbon monoxide through photoelectrocatalysis, which utilize the extended photoexcitation plasmon process to regulate and control a catalytic interface, thereby realizing the double breakthrough of current density and selectivity. The maximum current density of the system exceeds 900mA/cm 2, and the system still keeps excellent acetic acid selectivity and production efficiency after continuous operation for more than 270 hours, and is a more efficient and stable reaction system compared with the currently reported electrocatalytic technology. The invention can be realized by the following technical scheme that the system for synthesizing acetic acid by directionally converting carbon monoxide through photoelectrocatalysis is a photoelectrocatalysis reaction system and comprises a cathode reaction tank and a photoelectrocatalysis auxiliary component, wherein a cathode catalyst adopted by the cathode reaction tank is a copper-based catalyst which is directly supported on the surface of carbon paper, carbon monoxide reaction gas is introduced into the back surface of the carbon paper, the photoelectrocatalysis auxiliary component comprises a light source and a quartz glass plate, visible light is used as an excitation light source, a cathode catalyst layer is directly irradiated through the quartz glass plate, the evolution path of a surface reaction intermediate is changed, and the directional conversion of the carbon monoxide into the acetic acid is promoted. Further, the electrolyte is 0.1-5M KOH solution. Further, the light source adopted by the light auxiliary component is a single-wavelength LED light source, the adjustable range of the optical power density is 0.5-3.5W/cm 2, and the wavelength is 532nm. Further, the reaction pressure is 0.5 to 5bar. The copper-based catalyst is prepared by dissolving copper acetate in