CN-121972128-A - Silicon dioxide compound and preparation method and application thereof

CN121972128ACN 121972128 ACN121972128 ACN 121972128ACN-121972128-A

Abstract

The invention discloses a silicon dioxide compound, a preparation method and application thereof. The preparation method of the silicon dioxide compound comprises the following steps of reacting a silicon source, manganese salt and inorganic acid in a solvent, and calcining to obtain the silicon dioxide compound. The preparation method adopts a one-pot cogel method, so that manganese participates in the reaction at the initial stage of hydrolysis and polycondensation of a silicon source, and Si-O-Mn chemical bonds are formed by compounding at the molecular level, so that the manganese is uniformly dispersed at the atomic level in a silica gel network, is firmly combined and is not easy to run off, thereby being beneficial to catalyzing and oxidizing toluene and adsorbing heavy metals in water, and having wide application prospect.

Inventors

RAN XIANQIANG
WANG YAN
QIN SHUFANG
HUANG SHIWEI
LI QIANG

Assignees

上海映智研磨材料有限公司
衢州博来纳润电子材料有限公司

Dates

Publication Date: 20260505
Application Date: 20251231

Claims (10)

1. A method for preparing a silica composite, comprising the steps of: and (3) reacting a silicon source, manganese salt and inorganic acid in a solvent, and calcining to obtain the silicon dioxide compound.
2. The method of claim 1, wherein the silicon source is selected from one or more of ethyl orthosilicate, methyl orthosilicate, and sodium silicate; And/or the manganese salt is selected from one or more of manganese nitrate, manganese acetate and manganese sulfate; And/or the solvent is selected from one or two of water and ethanol; and/or the inorganic acid is selected from one or more of hydrochloric acid, nitric acid and sulfuric acid.
3. The method of claim 2, wherein the molar ratio of the silicon source to the manganese salt is 1 (0.01-0.3); And/or the molar ratio of the silicon source and the inorganic acid is 1 (0.1-5).
4. The method according to claim 1, wherein the reaction temperature is 40 to 80 ℃; and/or the reaction time is 2-12 h; And/or the pH value of the reaction is 2.5-3.5.
5. The method according to claim 1, wherein the calcination temperature is 300 to 600 ℃; and/or the calcination time is 2-6 hours.
6. The method of claim 1, further comprising aging and drying after the reacting.
7. The method according to claim 6, wherein the aging time is 12 to 48 hours; and/or the drying temperature is 60-120 ℃.
8. A silica composite obtainable by the process according to any one of claims 1 to 7.
9. The silica composite of claim 8 wherein the manganese element is present in an amount of 1 to 20 weight percent based on the total mass of the silica composite.
10. Use of the silica composite according to claim 9 or 10 in at least one of the following: A1 As a catalyst in the catalytic oxidation of volatile organic compounds; a2 As an adsorbent for adsorbing heavy metals in a water body.

Description

Silicon dioxide compound and preparation method and application thereof Technical Field The invention relates to the technical field of nano materials, in particular to a silicon dioxide compound and a preparation method and application thereof. Background Manganese oxides (e.g., mnO 2、Mn2O3、Mn3O4, etc.) have shown great potential in the fields of environmental catalysis, battery electrodes, adsorbents, etc., due to their excellent redox capacity, catalytic activity, and electrochemical properties. However, the surface energy of pure manganese oxide is extremely high, so that the pure manganese oxide can spontaneously agglomerate into large particles like a magnet, meanwhile, the pure manganese oxide is compact in structure or easy to sinter, and is difficult to form a high specific surface area, in addition, the manganese oxide is easy to dissolve in the reaction, easy to collapse in structure, so that the stability is poor, and therefore, the application effect of the manganese oxide is comprehensively limited. Currently, active components (such as transition metal or noble metal) are often loaded on carriers with high specific surface areas (such as silica gel, molecular sieve, alumina and the like) to prepare the heterogeneous solid catalyst so as to improve the dispersibility and stability of manganese oxide. Common methods for preparing heterogeneous solid catalysts include coprecipitation, impregnation, co-mixing, and the like. The precipitation method is to uniformly disperse and load the metal with catalytic activity and metal oxide on the surface of a carrier to prepare a supported catalyst by changing the active component into insoluble precipitate by using a precipitator in a solution with the active component. The co-mixing method is to mechanically mix the carrier with the active component, extrude, shape and calcine. The impregnation method is to put the carrier into liquid containing active components for impregnation, and after the impregnation is balanced, the carrier is subjected to post-treatments such as drying, roasting, activation and the like, so as to obtain the metal supported catalyst. Silica sol has a high specific surface area, good dispersibility and stability, and is widely used as a catalyst carrier, a coating additive, a binder, and the like. There have been attempts to combine manganese with silicon-based materials by simple physical mixing or post-impregnation. For example, manganese species in materials prepared by impregnation tend to agglomerate on the surface of silica sol particles and fall off under severe reaction conditions (e.g., high temperature, liquid phase), resulting in performance degradation. For example, CN201410249742.8 discloses a catalyst and a catalyst carrier for advanced wastewater treatment, and a preparation method of the catalyst and the catalyst carrier, which comprises the steps of firstly preparing a porous silica gel carrier, then immersing the porous silica gel carrier in an immersion liquid containing active metal components, and then washing, drying and calcining at high temperature to obtain the catalyst for advanced wastewater treatment, thereby reducing COD in wastewater. However, the two methods can lead to the problems of uneven distribution of manganese element, weak binding force with silicon substrate, easy loss, unsatisfactory modification effect and the like. Therefore, the silicon dioxide compound with simple process, uniform dispersion of manganese element, firm combination and stable performance and the preparation method thereof are developed, and the silicon dioxide compound has important practical significance and industrial value. Disclosure of Invention In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a silica composite, a method for its preparation and its use. To achieve the above and other related objects, the present invention is achieved by the following technical means. The first aspect of the present invention provides a method for preparing a silica composite, comprising the steps of: and (3) reacting a silicon source, manganese salt and inorganic acid in a solvent, and calcining to obtain the silicon dioxide compound. In some embodiments, the silicon source is selected from one or both of tetraethyl orthosilicate (TEOS), methyl orthosilicate, and sodium silicate. In certain embodiments, the silicon source is selected from ethyl orthosilicate. In some embodiments, the manganese salt is selected from one or more of manganese nitrate, manganese acetate, and manganese sulfate. In some embodiments, the solvent is selected from one or both of water and ethanol. In certain embodiments, the mineral acid is selected from one or more of hydrochloric acid, nitric acid, and sulfuric acid. The inventors have tried to use alkaline conditions for the reaction during the experiment, however, it was found that manganese salt precipitates are formed under the conditions,