Selective oxidation of furan based alcohols via electro-generative process

Abstract

This invention concerns a method for the production of at least a furanic compound having at least one aldehyde function and electrical power, by oxidizing at least a furanic compound having at least one hydroxyl function.

Claims

1. A process for the production of a furanic compound having at least one aldehyde function and electrical power, by oxidizing a furanic compound having at least one hydroxyl function, wherein the oxidizing is performed in an electro-generative device having an anode, a cathode and a separator, wherein the furanic compound having at least one hydroxyl function is an anode reactant and an oxidant is a cathode reactant.

2. The process according to claim 1, wherein the furanic compound having at least one hydroxyl function is selected from a group consisting of furfuryl alcohol, hydroxymethylfurfural, bis(hydroxymethyl)furan, 5-methoxymethylfurfuryl alcohol, 5-hydroxymethylfurancarb oxylic acid, and bis(5-hydroxymethylfuranmethyl) ether.

3. The process according to claim 1, wherein the furanic compound having at least one aldehyde function is selected from a group consisting of furfural, hydroxymethylfurfural, 2,5-furandicarbaldehyde, 5-methoxymethylfurfural, 5-formylfurancarboxylic acid and bis(5-formylmethylfurnmethyl) ether.

4. The process according to claim 1, wherein the electro-generative device is a fuel cell or H-shape cell.

5. The process according to claim 1, wherein the anode and cathode comprise a catalyst, said catalyst being Pt.

6. The process according to claim 1, wherein the anode and cathode comprise at least one catalyst selected from a group consisting of Ru, Rh, Au, Pd, Pt, Ir, Ta, Ni, Ag, Cu, Fe, Mn, Cr, Ti, Co, Zn, Zr, Y, Ce, Al N, and P.

7. The process according to claim 1, wherein the anode and cathode comprises catalysts applied to a support.

8. The process according to claim 1, wherein an electric potential is generated and is between 0.001-0.5V.

9. The process according to claim 1, wherein the furanic compound having at least one hydroxyl function is dissolved in a solvent with a concentration between 0.01 mol/L to 5 mol/L.

10. The process according to claim 1, wherein the oxidizing is performed for 15-45 hours.

11. The process according to claim 1, wherein the furanic compound having at least one hydroxyl function is dissolved in a solvent with a pH between 0.01-7.

12. The process according to claim 1, wherein the oxidizing is performed at a temperature between 10-200 C.

13. The process according to claim 1, wherein the separator is Nafion proton exchange membrane.

14. The process according to claim 13, wherein the thickness of membrane is between 100-300 m.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 Polarization curves obtained under the conditions in Example 1.

EXPERIMENTAL PART

Example 1

(2) The designed electrode reactions under acidic conditions are shown as below

(3) ##STR00001##

(4) The theoretical calculation gives standard Gibbs energy of the reaction with 189.11 kJ/mol, and the theoretical generated voltage is 0.98V.

(5) The anode reactant, HMF, was dissolved into water to get a 0.1 M solution with the addition of 0.1 M H.sub.2SO.sub.4 to reach a pH of 0.99. It was fed to anode compartment of a standard PEMFC (polymer exchange membrane fuel cells) with a flow rate of 10 ml/min in a closed loop.

(6) The cathode reactant, oxygen, was fed to cathode compartment of the same fuel cell with a flow rate of 100 sccm under 1 bar.

(7) 2 mg/cm.sup.2 PtRu and Pt catalysts were coated on carbon cloth respectively and then hot pressed to make a membrane electrode assembly (MEA) with Nafion in the middle as proton exchange membrane.

(8) The reaction was performed by heating both anode and cathode to 50 C. for 41 hours.

(9) Under the above conditions, the reaction could reach an open circuit voltage of 0.47 V, and a maximum power density of 0.64 mW/cm.sup.2, as shown in FIG. 1. To allow faster reaction rate, the cell was short circuit connected for 41 hours.

(10) After reaction, the final solution was quantitatively studied by HPLC. The main product was identified to be 2,5-furandicarbaldehyde (FDA) with a selectivity of 80% and a yield of about 40%. The conversion of HMF was 51%.

Example 2

(11) The anode reactant, HMF, was dissolved into water to get a 0.1 M solution with the addition of 0.1 M H.sub.2SO.sub.4 to reach a pH of around 1. It was fed to anode compartment of a standard PEMFC (polymer exchange membrane fuel cells) with a flow rate of 1 ml/min in a closed loop.

(12) The cathode reactant, oxygen, was fed to cathode compartment of the same fuel cell with a flow rate of 100 sccm under 1 bar.

(13) 2 mg/cm.sup.2 PtRu and Pt catalysts were coated on carbon cloth respectively, and then hot pressed to make a membrane electrode assembly (MEA) with Nafion (DuPont) proton exchange membrane with thickness of 178 m.

(14) The reaction was performed by heating both anode and cathode to 50 C. for 41 hours.

(15) TABLE-US-00001 TABLE 1 Reaction results of electro-generative oxidation from HMF to FDA by using Nafion membrane with thickness of 178 m. Membrane HMF thickness Power conversion Selectivity (%) (m) generation (%) FDA HFCA FFCA FDCA 178 415 mV, 46.3 87.3 3.4 9.0 0.3 214 W/cm.sup.2

Example 3

(16) For acidic conditions, Pt and PtRu catalysts have been tested for HMF oxidation, by using Nafion proton exchange membrane. The anode reactant, HMF, was dissolved into water to get a 0.1 M solution with the addition of 0.1 M H.sub.2SO.sub.4 to reach a pH of around 1. It was fed to anode compartment of a standard PEMFC (polymer exchange membrane fuel cells) with a flow rate of 5 ml/min in a closed loop.

(17) The cathode reactant, oxygen, was fed to cathode compartment of the same fuel cell with a flow rate of 100 sccm under 1 bar.

(18) PtRu and Pt were used for anode catalysts and Pt was used for cathode catalyst. 2 mg/cm.sup.2 PtRu and Pt catalyst were used for HMF oxidation, and were coated on carbon cloth to form anode, respectively. The cathode was coated with Pt catalyst for O.sub.2 reduction. Both electrodes were hot pressed to make a membrane electrode assembly (MEA) with Nafion (DuPont) proton exchange membranes in between.

(19) The anode and cathode were short circuited for the reaction at 50 C. for 41 hours.

(20) TABLE-US-00002 TABLE 2 Summary of reaction results of electro-generative oxidation of HMF to FDA under acidic conditions by using a proton exchange membrane and different catalysts. Catalyst HMF on Power conversion Selectivity (%) Anode generation (%) FDA HFCA FFCA FDCA Pt 156 mV 34.1 76.7 1.4 19.9 2.0 90 W/cm.sup.2 PtRu 381 mV 50.9 79.8 1.6 18.1 0.5 102 W/cm2

Example 4

(21) The anode reactant, HMF, was dissolved into water to get a 0.1 M solution with the addition of 0.1 M H.sub.2SO.sub.4 to reach a pH of around 1. It was fed to anode compartment of a standard PEMFC (polymer exchange membrane fuel cells) with a flow rate of 5 ml/min in a closed loop.

(22) The cathode reactant, oxygen, was fed to cathode compartment of the same fuel cell with a flow rate of 100 sccm under 1 bar.

(23) 2 mg/cm.sup.2 PtRu and Pt catalyst were coated on carbon cloth respectively, and then hot pressed to make a membrane electrode assembly (MEA) with Nafion (DuPont) proton exchange membranes with thickness of 177 m.

(24) The reaction was performed by heating both anode and cathode to 50 C. for 16 hours.

(25) TABLE-US-00003 TABLE 3 Reaction results of electro-generative oxidation of HMF to FDA at 16 hours. HMF Time Power conversion Selectivity (%) (hrs) generation (%) FDA HFCA FFCA FDCA 16 100 mV, 25.5 87.9 2.0 9.9 0.2 30 W/cm.sup.2

Example 5

(26) The anode reactant, HMF, was dissolved into water to get a 0.1 M solution with the addition of 0.1 M H.sub.2SO.sub.4 to reach a pH of around 1. It was fed to anode compartment of a standard PEMFC (polymer exchange membrane fuel cells) at a flow rate of 5 ml/min in a closed loop.

(27) Two cathode reactants, oxygen and air, were studied as cathode fuel, respectively, which was supplied to cathode compartment at a flow rate of 100 sccm under 1 bar.

(28) 2 mg/cm.sup.2 PtRu and Pt catalyst were coated on carbon cloth respectively, and then hot pressed to make a membrane electrode assembly (MEA) with Nafion (DuPont) proton exchange membranes with thickness of 177 m.

(29) The reaction was performed by heating both anode and cathode to 50 C. for 41 hours.

(30) TABLE-US-00004 TABLE 4 Summary of reaction results with different oxidant for electro-generative oxidation of HMF to FDA. HMF Power conversion Selectivity (%) Oxidant generation (%) FDA HFCA FFCA FDCA air 185 mV, 37.8 81.8 2.2 15.5 0.5 84 W/cm.sup.2 O.sub.2 381 mV 50.9 79.8 1.6 18.1 0.5 102 W/cm2

Example 6

(31) In this example, an H-shape electrochemical cell was used for eGen oxidation of HMF to FDA under acidic condition.

(32) The anode reactant, HMF, was dissolved into water to get a 0.1 M solution with the addition of 0.1 M H.sub.2SO.sub.4 to reach a pH of around 1. It was fed into anode compartment of a standard H-cell. PtRu catalyst was coated on carbon cloth, and then used as anode for HMF oxidation.

(33) The cathode compartment was also filled with 0.1 M H.sub.2SO.sub.4 solution. Air was bubbled into the solution at 200 ml/min. Pt mesh was used as cathode for oxygen reduction.

(34) Nafion proton exchange membrane was placed in the middle of the H-cell, and the two compartments were fixed as a whole cell.

(35) The two electrodes were short circuited for the reaction at 35 C. for 17 hours.

(36) Under the above conditions, the reaction could reach an open circuit voltage of 0.1V, and a maximum power density of 18 W/cm.sup.2 After reaction, the final solution was quantitatively studied by HPLC. The result showed that the main product was FDA with a selectivity of 90.3%.