NOVEL ELECTROCATALYTIC MEMBRANE REACTOR AND USE THEREOF IN PREPARATION OF HIGH-PURITY HYDROGEN

Abstract

The disclosure provides a novel electrocatalytic membrane reactor and use thereof in preparation of high-purity hydrogen. The electrocatalytic membrane reactor adopts an H-shaped electrolytic tank in which a cathode chamber is isolated from an anode chamber through a diaphragm, a membrane electrode is used as an anode, an auxiliary electrode is used as a cathode, a direct-current regulated power supply supplies a constant current, and the flow of a reaction solution is realized through a pump. In the disclosure, electrocatalysis is coupled with a membrane separation function, an oxygen evolution reaction is replaced with an organic electrochemical oxidation reaction in the anode chamber so as to reduce the overpotential of the oxygen evolution reaction, and a hydrogen evolving reaction is performed in the cathode chamber to prepare high-purity hydrogen.

Claims

1. A novel electrocatalytic membrane reactor, wherein an H-shaped electrolytic tank is adopted, a cathode chamber is isolated from an anode chamber through a diaphragm, a membrane electrode is used as an anode, an auxiliary electrode is used as a cathode, a direct-current regulated power supply supplies a constant current, and the flow of a reaction solution is realized through a pump.

2. The novel electrocatalytic membrane reactor according to claim 1, wherein the diaphragm is an ion exchange member or a proton exchange membrane.

3. The novel electrocatalytic membrane reactor according to claim 1, wherein the membrane electrode is a flat or tubular inorganic metal membrane, an oxide membrane or a carbon membrane.

4. The novel electrocatalytic membrane reactor according to claim 3, wherein the membrane electrode is supported with a notable metal and an oxide thereof as well as a transition metal oxide and a sulfide or a phosphide.

5. The novel electrocatalytic membrane reactor according to claim 1, wherein the cathode is a metal electrode or a graphite electrode.

6. A use of the novel electrocatalytic membrane reactor according to claim 1 in preparation of high-purity hydrogen.

7. The use according to claim 6, wherein high-purity hydrogen is prepared in the cathode chamber, and an electrochemical oxidation reaction is performed in the anode chamber.

8. The use according to claim 6, wherein the electrochemical oxidation reaction comprises an organic degradation reaction or an oxygen-containing compound preparation reaction.

9. The use according to claim 8, wherein the organic degradation comprises degradation of phenol and acid orange, and the oxygen-containing compound preparation comprises preparation of aldehyde and acid products by oxidation of benzyl alcohol, ethanol and furfural organics.

Description

DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1A is a diagram of an H-shaped tubular membrane electrocatalytic membrane reactor;

[0025] In the figure, 1, H-shaped electrolysis tank; 2, proton exchange membrane; 3, tubular membrane electrode as an anode; 4, metal electrode as a cathode; 5, direct current stabilized power supply; 6, peristaltic pump; 7, reactant product collection device; 8, feed liquid port; 9, discharge liquid port; 10, gas outlet.

[0026] FIG. 1B is a diagram of a flat membrane electrocatalytic membrane reactor;

[0027] In the figure, 21, end plate; 22, proton exchange membrane; 23, flat membrane electrode as an anode; 24, metal electrode as a cathode; 25, direct current stabilized power supply, 26, peristaltic pump; 27, reactant product collection device; 28, pole plate; 29, feed liquid port; 30, discharge liquid port; 31, gas outlet.

[0028] FIG. 2 shows a relationship between reaction retention time and COD as well as hydrogen production rate in example 1.

[0029] FIG. 3 is a comparison picture of a dye solution before and after treatment.

[0030] FIG. 4 is a relationship diagram between current density and dye decolorization rate as well as chemical oxygen demand (COD).

[0031] FIG. 5 is a total organic carbon (TCD) graph of high-purity hydrogen.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0032] The technical solution of the disclosure will be further described in detail in combination with specific embodiments.

EXAMPLE 1

[0033] Treatment of phenol-containing wastewater with H-shaped electrocatalytic membrane reactor

[0034] An electrocatalytic membrane reactor was constructed by using a porous titanium membrane supported with a cobalt oxide nano catalyst as an anode, a stainless steel wire as a cathode and an H-shaped electrolysis tank. A diaphragm used a Nafion proton exchange membrane, a stable current was supplied by a direct current power supply, a membrane operation process used a dead end filtration mode, one end of the membrane was closed, the other end of the membrane was connected with a peristaltic pump through a pipeline, and a negative pressure was continuously supplied by the pump to enhance its mass transfer process. The initial concentration of phenol was 2 mmolL.sup.−1, the concentration of electrolyte was 14.4 gL.sup.−1 Na.sub.2SO.sub.4, the current density of the membrane reactor was 1.0 mAcm.sup.−2, the retention time was 15 min, the removal rate of COD was 99%, the removal rate of TOC was 90%, and the yield of hydrogen per unit membrane area was 10 mL/h. When the reactor device was magnified to 10 folds, the yield of hydrogen was 100 mL/h, so as to realize the efficient treatment of phenol-containing wastewater and efficient hydrogen production.

[0035] A relationship between reaction retention time and COD as well as a hydrogen production rate is as shown in FIG. 2.

EXAMPLE 2

[0036] Treatment of azo dye wastewater coupled with hydrogen production with H-shaped electrocatalytic membrane reactor

[0037] An electrocatalytic membrane reactor was constructed by using a porous titanium membrane supported in situ with a cobalt oxide nano catalyst as an anode, a stainless steel wire as a cathode and an H-shaped electrolysis tank. A diaphragm used proton exchange membrane Nafion117, a stable current was supplied by a direct current power supply, a membrane operation process used a dead end filtration mode, one end of the membrane was closed, the other end of the membrane was connected with a peristaltic pump through a pipeline, and a negative pressure was continuously supplied by the pump to enhance its mass transfer process. The initial concentration of acid orange II was 10 mmolL.sup.−1, the concentration of electrolyte was 14.4 gL.sup.−1 Na.sub.2SO.sub.4, the current density of the membrane reactor was 1.0 mAcm.sup.−2, the retention time was 20 min, the decolorization rate after reaction was 100%, the removal rate of COD was 99%, the removal rate of TOC was 90%, and the hydrogen production rate was close to 100 mL/h. Through the disclosure, the efficient removal of acid orange II simulated azo dye wastewater and the production of high-purity hydrogen are realized.

[0038] Comparison pictures of a dye solution before and after treatment are as shown in FIG. 3.

[0039] A relationship between current density and dye decolorization rate as well as COD is as shown in FIG. 4.

EXAMPLE 3

[0040] Preparation of benzoic acid coupled with hydrogen production by electrocatalytic oxidation of benzyl alcohol with H-shaped electrolytic tank electrocatalytic membrane reactor.

[0041] An electrocatalytic membrane reactor was constructed by using a porous titanium membrane supported in situ with a cobalt oxide nano catalyst as an anode, a stainless steel wire as a cathode and an H-shaped electrolysis tank. A diaphragm used a Nafion proton exchange membrane, a stable current was supplied by a direct current power supply, a membrane operation process used a dead end filtration mode, one end of the membrane was closed, the other end of the membrane was connected with a peristaltic pump through a pipeline, and a negative pressure was continuously supplied by the pump to enhance its mass transfer process. The initial concentration of benzyl alcohol was 10 mmolL.sup.−1, the concentration of electrolyte was 4 gL.sup.−1 NaOH, the current density of the membrane reactor was 2.0 mAcm.sup.−2, the retention time was 20 min, the conversion rate of benzyl alcohol was 90%, the selectivity of benzoic acid was 99%, and the hydrogen production rate was 100 mL/h. The electrochemical synthesis of benzoic acid and production of high-purity hydrogen are realized.

[0042] FIG. 5 is a TCD graph of high-purity hydrogen.

EXAMPLE 4

[0043] Preparation of 2,5-furandicarboxylic acid (FDCA) coupled with hydrogen production by electrocatalytic oxidation of 5-hydroxymethyl furfural (HMF) with H-shaped electrolysis tank electrocatalytic membrane reactor

[0044] An electrocatalytic membrane reactor was constructed by using a porous titanium membrane supported in situ with a cobalt oxide nano catalyst as an anode, a stainless steel wire as a cathode and an H-shaped electrolysis tank. A diaphragm used a Nafion proton exchange membrane, a stable current was supplied by a direct current power supply, a membrane operation process used a dead end filtration mode, one end of the membrane was closed, the other end of the membrane was connected with a peristaltic pump through a pipeline, and a negative pressure was continuously supplied by the pump to enhance its mass transfer process. The initial concentration of 5-hydroxymethyl furfural was 20 mmolL.sup.−1, the concentration of electrolyte was 4 gL.sup.−1 NaOH, the current density of the membrane reactor was 2.0 mAcm.sup.−2, the retention time was 15 min, the conversion rate of furfural was 99%, the selectivity of FDCA was 99%, and the hydrogen production rate was 90 mL/h. The electrochemical synthesis of HMF and production of high-purity hydrogen are realized.