阅读说明：本技术 一种可见光催化选择性氧化葡萄糖的方法 (Method for selectively oxidizing glucose by visible light catalysis ) 是由 杨昌军 殷杰 邓克俭 张丙广 于 2020-06-24 设计创作，主要内容包括：本发明属于化工领域,具体公开了一种可见光催化选择性氧化葡萄糖的方法。该方法以BiVO<Sub>4</Sub>/CoPz(hmdtn)<Sub>4</Sub>为光催化剂,直接以空气中的分子氧为氧化剂,在λ≥420 nm可见光光照的条件下,在水环境中可以实现有效地光催化氧化葡萄糖制备高附加值化学品。该方法可以利用太阳光能和空气,在常温常压下实施葡萄糖的氧化,为葡萄糖的氧化制备高附加值化学品提供一种绿色且节能的选择性氧化方法。(The invention belongs to the field of chemical industry, and particularly discloses a method for selectively oxidizing glucose by visible light catalysis. BiVO is adopted in the method 4 /CoPz(hmdtn) 4 Is a photocatalyst, directly takes molecular oxygen in the air as an oxidant, and can realize the effective photocatalytic oxidation of glucose in water environment to prepare high added value under the condition of the visible light illumination with the lambda being more than or equal to 420nmA chemical. The method can utilize solar energy and air to carry out the oxidation of glucose at normal temperature and normal pressure, and provides a green and energy-saving selective oxidation method for preparing high value-added chemicals by the oxidation of glucose.)

1. A method for selectively oxidizing glucose by visible light catalysis is characterized in that: BiVO is adopted in the method₄/CoPz(hmdtn)₄The composite photocatalyst is a visible light photocatalyst, and the molecular oxygen in the air is used as oxygenA reagent, under the irradiation of visible light with lambda being more than or equal to 420nm, water is used as a solvent, and glucose is oxidized to prepare a high value-added chemical;

the high value-added chemicals are gluconic acid, arabinose, erythrose and formic acid;

the BiVO₄/CoPz(hmdtn)₄To convert CoPz (hmdtn)₄Loaded in BiVO₄The above.

2. The method of claim 1, wherein the CoPz (hmdtn)₄The loading amount of the catalyst is 0.25-3%.

3. The method of claim 1, wherein the BiVO is₄The crystal form is monoclinic scheelite type, tetragonal zircon type or tetragonal scheelite type.

4. The method of claim 1, wherein the BiVO is₄/CoPz(hmdtn)₄The preparation method comprises the following steps:

BiVO (bismuth oxide) is added₄Adding the mixture into a solvent A, fully dispersing, and adding a solvent B containing tetrakis (1, 4-dithiino) tetraazacobalt porphyrin to BiVO₄Uniformly mixing in a dispersion system, removing the solvent, and drying in vacuum to obtain the composite photocatalyst BiVO₄/CoPz(hmdtn)₄。

5. The method according to claim 4, wherein the solvent A is the same as the solvent B and is N, N-dimethylformamide, acetonitrile or tetrahydrofuran.

6. The method according to any one of claims 1 to 5, wherein the method is: adding a composite photocatalyst into a glucose aqueous solution, stirring to fully disperse the catalyst in a reaction system, directly using oxygen in the air as an oxidant, and taking visible light with the lambda of more than or equal to 420nm and the visible light intensity of 0.78W-cm^-2-1.68 W·cm^-2Under irradiation of (a) to effect oxidation of glucose.

Technical Field

The invention relates to the field of chemical industry, in particular to a method for selectively oxidizing glucose by visible light catalysis, which uses BiVO₄/CoPz(hmdtn)₄The photocatalyst and oxygen in the air are used as oxidantsVisible light photocatalytically oxidizes glucose to prepare high value-added chemicals.

Background

Glucose is a monosaccharide which is most widely distributed in nature, and an oxidation product of the glucose can be used as an important intermediate and a chemical product to be applied to the fields of chemical industry, food, medicine and the like. Therefore, research on obtaining high value-added chemicals through oxidation of glucose has received extensive attention. From the perspective of green chemical industry and sustainable development, the method has important significance and application value in preparing high value-added chemicals by utilizing the characteristic that glucose can be dissolved in water, taking sunlight as a driving force, taking molecular oxygen in air as an oxidant and utilizing a photocatalysis technology to realize selective oxidation of glucose under mild conditions in a water environment.

The core of the photocatalysis technology is the development of a photocatalyst. The composition of the solar spectrum is mostly visible light, the metalloporphyrin has strong absorption in a visible light region, and the inorganic semiconductor photocatalyst and the metalloporphyrin are compounded to form the composite photocatalyst, so that the utilization rate of sunlight can be improved, the separation efficiency of photo-generated electron-hole pairs can be enhanced, and the photocatalytic oxidation efficiency of the photocatalyst can be improved. The composite photocatalyst based on the inorganic semiconductor and the metalloporphyrin is applied to the photocatalytic selective oxidation reaction of glucose, renewable solar energy can be used as a light source, meanwhile, environment-friendly oxygen is used as an oxidant, the use of a strong corrosive oxidant can be avoided, the selectivity of an oxidation product is improved through optimization of photocatalytic reaction conditions, and a green and energy-saving selective oxidation method is provided for oxidation of glucose.

Disclosure of Invention

Aiming at the defects of the existing glucose oxidation method, the invention utilizes the dipping method to oxidize BiVO (BiVO) to develop a green and energy-saving method for preparing high value-added chemicals by glucose oxidation₄With tetrakis (hydroxymethyl) tetrakis (1, 4-dithiin) tetraazacobalt porphyrin (CoPz (hmdtn)₄) Composite photocatalyst BiVO (bismuth VO) is prepared through compounding₄/CoPz(hmdtn)₄And develops a composite photocatalyst BiVO₄/CoPz(hmdtn)₄Visible light catalytic activated molecular oxygenUse of oxidized glucose. The composite photocatalyst BiVO prepared by the invention₄/CoPz(hmdtn)₄The visible light photocatalysis can efficiently oxidize glucose into gluconic acid, arabinose, erythrose and formic acid.

The invention relates to a method for preparing a compound of CoPz (hmdtn)₄Loaded in BiVO₄Composite photocatalyst BiVO prepared on the surface₄/CoPz(hmdtn)₄With BiVO₄/CoPz(hmdtn)₄Is a visible light catalyst, takes molecular oxygen in the air as an oxidant and water as a solvent, and researches show that the composite photocatalyst BiVO is compounded under the conditions of normal temperature and normal pressure under the irradiation of visible light with the lambda being more than or equal to 420nm₄/CoPz(hmdtn)₄Has high-efficiency photocatalytic oxidation capacity on glucose, and can obtain gluconic acid, arabinose, erythrose and formic acid.

In order to achieve the above purpose of the present invention, the technical scheme adopted by the present invention is as follows:

composite photocatalyst BiVO with high activity₄/CoPz(hmdtn)₄The preparation method comprises the following steps:

BiVO (bismuth oxide) is added₄Adding the mixture into a solvent A, fully dispersing, and adding a solvent B containing tetrakis (1, 4-dithiino) tetraazacobalt porphyrin to BiVO₄Uniformly mixing in a dispersion system, removing the solvent, and drying in vacuum to obtain the composite photocatalyst BiVO₄/CoPz(hmdtn)₄。

CoPz(hmdtn)₄The load of the catalyst refers to a composite photocatalyst BiVO₄/CoPz(hmdtn)₄Middle CoPz (hmdtn)₄And BiVO₄In mass percent of (1), CoPz (hmdtn)₄The loading of (b) is 0.25% to 3%, preferably 0.5% to 2%.

Preferably, the BiVO₄The crystal form is monoclinic scheelite type, tetragonal zircon type or tetragonal scheelite type.

More preferably, the BiVO₄Is monoclinic scheelite crystal form.

The solvent A is N, N-Dimethylformamide (DMF), acetonitrile or tetrahydrofuran; preferably, solvent a is N, N-dimethylformamide.

The solvent B is the same as the solvent A. The amount of solvent a is greater than the amount of solvent B.

The composite photocatalyst BiVO of the invention₄/CoPz(hmdtn)₄Can be applied to the field of photocatalysis. Preferably, the composite photocatalyst is applied to photocatalytic oxidation of glucose. With BiVO₄/CoPz(hmdtn)₄Is a visible light catalyst, takes molecular oxygen in the air as an oxidant, and has a visible light intensity of 0.78 W.cm at lambda of more than or equal to 420nm^-2-1.68W·cm^-2Under the irradiation of the light source, water is used as a solvent, and glucose is subjected to photocatalytic oxidation under the conditions of normal temperature and normal pressure to obtain gluconic acid, arabinose, erythrose and formic acid.

The composite photocatalyst is applied to photocatalytic oxidation of glucose, and comprises the following specific steps:

adding glucose aqueous solution into a jacket light reaction bottle, adding a composite photocatalyst, fully dispersing the catalyst in a reaction system under the condition of keeping out of the sun by stirring, starting circulating condensed water, directly using oxygen in the air as an oxidant, and taking visible light with the lambda of more than or equal to 420nm and the visible light intensity of 0.78W cm^-2-1.68W·cm^-2And the oxidation of glucose is realized under the condition of illumination.

The concentration of the glucose aqueous solution is preferably 0.5 mmol.L^-1-7mmol·L^-1More preferably 0.5 mmol. multidot.L^-1-3mmol·L^-1Most preferably 0.5 to 1 mmol. multidot.L^-1；

When in use, glucose in the glucose aqueous solution and the composite photocatalyst BiVO₄/CoPz(hmdtn)₄Middle CoPz (hmdtn)₄The dosage ratio is (0.025-0.35) mmol: (0.075-0.9) mg, optimally (0.025-0.05) mmol: (0.15-0.6) mg.

Further, 50mL of 0.5 mmol. multidot.L was put into a jacketed photoreaction flask^-1Adding 30mg of composite photocatalyst BiVO into the glucose aqueous solution₄/CoPz(hmdtn)₄(CoPz(hmdtn)₄The loading amount of the catalyst is 2 percent), and the catalyst is fully dispersed in the reaction system by magnetic stirring for 30min under the condition of keeping out of the sun. And starting circulating condensate water to maintain the temperature of the reaction system unchanged. The mouth of the photoreaction bottle is opened,directly contacting with the atmosphere, and having a light intensity of 1.68W cm^-2The reaction is carried out for 9 hours under the condition that the lambda is more than or equal to 420nm of visible light illumination, the conversion rate of glucose is 40.6 percent, and the selectivity of oxidation products is as follows: the selectivity of gluconic acid is 13.8%, the selectivity of arabinose is 27.1%, the selectivity of erythrose is 12.7%, and the selectivity of formic acid is 18.2%.

Compared with the prior art, the invention has the advantages and beneficial effects that:

(1) BiVO is used in the invention₄/CoPz(hmdtn)₄The catalyst is a visible light catalyst, can directly perform visible light catalytic oxidation on glucose at normal temperature and normal pressure to obtain high value-added chemicals, and the condition of the photocatalytic reaction is milder than that of the traditional catalysis.

(2) The invention takes the visible light with the lambda being more than or equal to 420nm as the light source, directly takes the oxygen in the air as the oxygen source, realizes the catalytic oxidation of the glucose in the pure water environment to prepare the high value-added chemical, and provides a green and energy-saving selective oxidation method for the oxidation of the glucose.

Drawings

FIG. 1 shows CoPz (hmdtn)₄Ultraviolet-visible absorption spectrum of (a).

FIG. 2 shows CoPz (hmdtn)₄MALDI-TOF MS spectrum of (1).

FIG. 3 is BiVO₄XRD pattern of (a).

FIG. 4 is BiVO₄/CoPz(hmdtn)₄(CoPz(hmdtn)₄Load of 2%) and the corresponding element distribution map.

FIG. 5 is BiVO₄And BiVO₄/CoPz(hmdtn)₄Ultraviolet-visible diffuse reflection absorption spectrum diagram.

FIG. 6 is BiVO₄、CoPz(hmdtn)₄And BiVO₄/CoPz(hmdtn)₄(CoPz(hmdtn)₄Loading of 2%) of the sample.

FIG. 7 is BiVO₄、CoPz(hmdtn)₄And BiVO₄/CoPz(hmdtn)₄(CoPz(hmdtn)₄Loading of 2%) was determined.

FIG. 8 is quenching agent vs BiVO₄/CoPz(hmdtn)₄(CoPz(hmdtn)₄Loading of 2%) the effect of photocatalytic oxidation of glucose.

Detailed Description

The method for the visible light catalytic selective oxidation of glucose according to the present invention is further described below by way of specific examples, but the following should not be construed to limit the scope of the claimed invention in any way.

The main raw materials used in the following examples are as follows:

the molecular structure of the tetrakis (1, 4-dithiin) tetraazacobalt porphyrin is as follows:

(1) tetramethylol tetrakis (1, 4-dithiin) tetraazacobalt porphyrin (abbreviated as CoPz (hmdtn))₄) The synthesis method comprises the following steps: CoPz (hmdtn)₄Reference Journal of molecular catalysis A Chemical (2013,372: 114-. For the synthesized CoPz (hmdtn)₄The structural characterization was performed by UV-visible absorption spectroscopy and MALDI-TOF MS as shown in FIG. 1 and FIG. 2, respectively.

(2)BiVO₄The XRD pattern of the commercial product is shown in figure 3, which shows that the BiVO₄Has monoclinic scheelite crystal structure.