CN110128274B

CN110128274B - Method for synthesizing diphenyl carbonate by dimethyl carbonate ester exchange

Info

Publication number: CN110128274B
Application number: CN201910453461.7A
Authority: CN
Inventors: 陈彤; 肖忠良; 张华�; 王公应
Original assignee: Chengdu Organic Chemicals Co Ltd of CAS; University of Chinese Academy of Sciences
Current assignee: Chengdu Organic Chemicals Co Ltd of CAS; University of Chinese Academy of Sciences
Priority date: 2019-05-28
Filing date: 2019-05-28
Publication date: 2022-02-22
Anticipated expiration: 2039-05-28
Also published as: CN110128274A

Abstract

The invention relates to a method for synthesizing diphenyl carbonate by dimethyl carbonate ester exchange, which takes dimethyl carbonate and phenol as raw materials, mesoporous silica supported bismuth silicate as a catalyst, and the mesoporous silica supported bismuth silicate as the catalyst consists of a mesoporous silica carrier and an active component bismuth silicate, and mainly solves the problems that the catalyst is difficult to separate and recycle, cannot be reused and the like. The mesoporous silica loaded bismuth silicate used in the method for synthesizing diphenyl carbonate has high activity and good selectivity, the conversion rate of phenol reaches 42%, and the ester exchange selectivity reaches 99.5%. The mesoporous silica-supported bismuth silicate used in the method is a heterogeneous catalyst, is insoluble in a reaction system, is easy to separate from the system after reaction, can be repeatedly used, and can be regenerated and restored to the initial activity by simple roasting.

Description

Method for synthesizing diphenyl carbonate by dimethyl carbonate ester exchange

Technical Field

The invention relates to a method for synthesizing diphenyl carbonate by dimethyl carbonate ester exchange.

Background

Diphenyl carbonate (DPC) is an important chemical intermediate, mainly used in the plastics industry, and one of the most important applications is the synthesis of Polycarbonate (PC) by polycondensation with bisphenol a.

The non-phosgene synthesis method of DPC mainly comprises oxidative carbonylation method and ester exchange method. Wherein the oxidative carbonylation method uses CO and O₂And phenol are used as raw materials to directly synthesize the DPC under the action of a catalyst, and the method uses a complex catalytic system with high price, low yield and selectivity of the DPC and severe reaction conditions to limit the industrial application of the DPC. The exchange synthesis of DPC by dimethyl carbonate (DMC) and phenol ester is the non-phosgene DPC synthesis route with most industrial prospect. Organotin and organotitanium catalysts are generally used as homogeneous catalysts.

In patent document CN1698960A, Wang Gong Ying et al use titanoceneThe phenol conversion rate can reach 43-52% by using similar catalysts; du et al (Du Z P, Xiao Y H. Catal Commun,2008,9:239-₂The conversion rate of O and dimethyl carbonate can reach 50.8%. The homogeneous catalyst has high activity and good selectivity. But the reaction system is difficult to separate and recycle, which causes difficult product separation.

At present, the heterogeneous catalyst for synthesizing diphenyl carbonate by the exchange of dimethyl carbonate and phenol mainly has the problem of poor repeated use effect. Tong et al (Tong D S, Yao J.J Mol Cal A: Chem,2007,268:120-126) studied the catalytic performance of metal oxide catalyst in the transesterification of dimethyl carbonate and phenol, and the active component studied is MoO₃、V₂O₅、CuO、Nb₂O₅、Cr₂O₃、TiO₂、Sb₂O₃Etc. wherein V₂O₅The yields of Methyl Phenyl Carbonate (MPC) and diphenyl carbonate were 21.6% and 12.1%, respectively; li et al (Li Z H, Cheng B.J Mol Cal A: Chem,2008,289:100-105) MoO₃Loaded on SiO₂、MCM-41、Al₂O₃、ZrO₂On a carrier, when MoO₃When the MPC and the DPC are loaded on MCM-41, the yield of the MPC and the yield of the DPC are greatly improved, and the yield of the MPC and the yield of the DPC are respectively 2.6 percent and 39.6 percent; ge, etc. (Puxin, Libi Jing, etc. chemical Proc 2011,69:2328-₂CNT catalyst, wherein titanium dioxide is present in amorphous form. The phenol conversion rate of the catalyst can reach 45.7 percent, and the phenol conversion rate is reduced to 35.2 percent after the catalyst is used for four times; wang et al (Wang S L, Tang R Z. chem Eng Sci,2015,138:93-98) TiO prepared by Sol-gel method₂The supported phosphomolybdic acid catalyst has the phenol conversion rate of 50.4 percent, and can be repeatedly used for 4 times, and the phenol conversion rate is reduced to 29.5 percent. Zhang et al (Zhang Y Z, Xiao Z L. Res Chem Intermed,2016,42(9): 7213-.

In the document CN1803282A, the yield of the ester exchange product can reach 30% by using vanadium-copper composite oxide as the catalyst. In CN191423476A, heteropoly compound was used as catalyst, the yield of diphenyl carbonate reached 30%, and the ester exchange selectivity reached 99.9%. In CN201010263740, the total yield of diphenyl carbonate and alkyl phenyl carbonate can reach 49.0% when chentong and the like perform ester exchange reaction to synthesize diphenyl carbonate by using titanium dioxide loaded on carbon nanotubes as a catalyst.

Disclosure of Invention

The invention aims to provide a method for synthesizing diphenyl carbonate by the exchange of dimethyl carbonate and phenol. The mesoporous silica-loaded bismuth silicate used in the method takes mesoporous silica as a carrier and bismuth silicate as an active component. The mesoporous silica carrier can be inorganic mesoporous silica or organic mesoporous silica, the molar ratio of bismuth to silicon is 0.1-0.4, and the mesoporous silica carrier is used after being treated at 250-500 ℃.

The invention has the beneficial effects that:

(1) the method has high efficiency. The method of the invention adopts mesoporous silica-supported bismuth silicate as a catalyst to synthesize diphenyl carbonate, and has good effect, the conversion rate of phenol reaches 41.5 percent, and the ester exchange selectivity is 99.5 percent.

(2) The catalyst used in the method of the invention is easy to separate and recycle. The mesoporous silica supported bismuth silicate used in the method is a heterogeneous catalyst and can be separated and recycled from the system through filtration.

(3) The catalyst used in the method can be reused. The mesoporous silica supported bismuth silicate catalyst used in the invention can be repeatedly used for three times, the activity is slightly reduced, and the catalyst can be regenerated after roasting treatment and is recovered to the initial activity.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

Uniformly mixing bismuth nitrate and inorganic mesoporous silicon oxide according to the molar ratio of bismuth to silicon of 0.1:1, grinding for 60min, and roasting at 200 ℃ for 6h to obtain the inorganic mesoporous silicon oxide supported bismuth silicate catalyst, which is recorded as a sample 1.

Example 2

Dissolving bismuth nitrate and inorganic mesoporous silicon oxide in a certain amount of absolute ethanol according to the molar ratio of bismuth to silicon of 0.3:1, stirring for 24 hours, then removing the solvent by rotary evaporation, and roasting the obtained solid at 400 ℃ for 2 hours to obtain the inorganic mesoporous silicon oxide supported bismuth silicate catalyst, which is recorded as sample 2.

Example 3

Uniformly mixing bismuth nitrate and ordered mesoporous organic silicon according to the molar ratio of bismuth to silicon of 0.1:1, grinding for 15min, and roasting at 300 ℃ for 5h to obtain the organic mesoporous silicon oxide supported bismuth silicate catalyst, which is recorded as a sample 3.

Example 4

Uniformly mixing bismuth nitrate and ordered mesoporous organic silicon according to the molar ratio of bismuth to silicon of 0.3:1, grinding for 20min, and roasting at 400 ℃ for 4h to obtain the organic mesoporous silicon oxide supported bismuth silicate catalyst, which is recorded as a sample 4.

Example 5

Dissolving bismuth nitrate and ordered mesoporous organic silicon in a certain amount of absolute ethanol according to the molar ratio of bismuth to silicon of 0.2:1, stirring for 12 hours, then removing the solvent by rotary evaporation, and roasting the obtained solid at 500 ℃ for 1 hour to obtain the organic mesoporous silicon oxide supported bismuth silicate catalyst, which is recorded as sample 5.

Example 6

This example provides a method for synthesizing diphenyl carbonate by dimethyl carbonate ester exchange, including: 0.6g of sample 1, sample 2, sample 3, sample 4 or sample 5 was placed in a three-necked flask equipped with a gas-guide tube, a thermometer, a constant-pressure dropping funnel and a rectifying column, nitrogen gas was introduced and 15g of phenol was added, and when heating was carried out to 175 ℃, dropwise addition of DMC was started, and the total amount of DMC added was 14 ml. The reaction was carried out for 9 hours from the start of the dropwise addition of DMC, and the product was quantified by gas chromatography, calibrated normalization, and the results are shown in Table 1:

TABLE 1 catalytic performance of mesoporous silicon supported bismuth silicate catalysts

The results in table 1 show that, with the catalyst (mesoporous silica supported bismuth silicate) provided by the embodiment of the present invention, the conversion rate of phenol can reach 41.5%, and the ester exchange selectivity can reach 99.5%.

Example 7

Sample 4 after the reaction of example 4 was filtered, washed with DMC, dried at 120 ℃ to obtain sample 4-1, and the transesterification reaction was performed according to the procedure of example 6.

Example 8

Sample 4-1 after the reaction of example 7 was filtered, washed with DMC, dried at 120 ℃ to give sample 4-2, and the transesterification reaction was carried out according to the procedure of example 6.

Example 9

The sample 4-2 after the reaction of example 8 was filtered, washed with DMC, dried at 120 ℃ to obtain sample 4-3, and the transesterification reaction was performed according to the procedure of example 6.

Example 10

The sample 4-3 after the reaction of example 9 was filtered, washed with DMC, dried at 120 ℃ and calcined at 400 ℃ to obtain sample 4-4, and the transesterification reaction was carried out according to the procedure of example 6.

TABLE 2 reusability of mesoporous silicon supported bismuth silicate catalysts

The results in table 2 show that the catalyst (mesoporous silica supported bismuth silicate) provided by the embodiment of the invention can be reused, has good reuse effect, does not affect transesterification selectivity, and can be regenerated after being calcined to restore the initial activity although the activity is slightly reduced after being used for multiple times.

In conclusion, by adopting the method for synthesizing diphenyl carbonate by dimethyl carbonate ester exchange, the conversion rate of phenol can reach 41.5 percent, and the ester exchange selectivity can reach 99.5 percent; and the catalyst has good repeated use effect.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for synthesizing diphenyl carbonate by dimethyl carbonate ester exchange is characterized in that dimethyl carbonate and phenol are used as raw materials, and mesoporous silica supported bismuth silicate is used as a heterogeneous catalyst; the heterogeneous catalyst is used in an amount satisfying, in terms of mass ratio: phenol 0.6: 15;

the mesoporous silica-loaded bismuth silicate consists of a mesoporous silica carrier and an active component bismuth silicate, and the molar ratio of bismuth to silicon is 0.1-0.4; the mesoporous silica carrier can be inorganic mesoporous silica or organic mesoporous silica; the mesoporous silica-supported bismuth silicate is used after being roasted at the temperature of 200-500 ℃.