**2. The titanium silicate materials used for diallyl ether and allyl-glycidyl ether epoxidation [19]**

Until now, only the TS-1 and Ti-MWW titanium silicate materials have been used in the epoxidation of DAE and AGE – with hydrogen peroxide. In the studies performed by Wu et al. [19], AGE was the semi-product which was formed during DAE epoxidation and it underwent among others further transformation to DGE. In the above mentioned research, at the first stage, the epoxidation of DAE with hydrogen peroxide was performed under vigorous stirring in a 20 ml glass flask, connected to a condenser. In the typical run, the appropriate amounts of DAE, solvent (acetonitrile, acetone, water, methanol, ethanol, dioxane), and the catalyst were mixed in the flask and heated to the desired temperature under the agitation. Next, aqueous hydrogen peroxide (30 wt%) was added to the mixture to start the reaction. The reaction was carried out at the temperature of 60°C for 0.5 h in case of Ti-MWW and for 1.5 h in case of TS-1. Both Ti-MWW and TS-1 materials showed different solvent effect. During the examinations over Ti-MWW catalyst, the highest conversion of DAE was obtained for acetonitrile (about 40 mol%) and acetone (about 39 mol%) as the solvents. The selectivity of AGE was the highest for acetonitrile, methanol, ethanol, and dioxane and amounted to about 71–79 mol%. The selectivity of DGE, which was formed as the product of AGE transformation (epoxidation of the next double bond), was the highest for water as the solvent (about 40 mol %). High values of the selectivity of this product also allow to obtain such solvents as: acetonitrile (about 29 mol%) and acetone (about 25 mol%). The efficiency of hydrogen peroxide conversion was the highest for examinations in acetonitrile (about 95 mol%), acetone (about 92 mol%), and dioxane (about 94 mol%). In methanol and in water, the efficiency of hydrogen peroxide conversion amounted to about 82–87 mol%. The lowest value of this function of the process was obtained for ethanol (61 mol%). The total conversion of hydrogen peroxide was the highest in acetonitrile and acetone (about 99–100 mol%). These studies showed that the Ti-MWW catalyst favoured aprotic solvents such as acetonitrile or acetone. A little worse results were obtained for water as the solvent.

(DAE) [19] with hydrogen peroxide over these catalysts. It can be caused by the fact that the epoxidation of AGE and DAE is very complicated, as in addition to the epoxidized ether derivatives, by-products formed by the decomposition of these ethers and their epoxidized derivatives, as well as products of further transformations of these decomposed products, i.e. glycidol and glycerol, are received. Moreover, during epoxidation, the epoxy rings may be opened and diols can be formed. However, due to numerous applications of diglycidyl ether – DGE (production of linear, branched, and cyclic oligoglycerols used in the production of surfactants, preparation of anti-arrhythmia agents, production of components of other pharmaceuticals and medicines, for example, cryptands, preparation of lubricating oil additives, and synthesis of aminoethers), the epoxidation of AGE with hydrogen peroxide over Ti-SBA-15 is very interesting and worth further examinations. The simultaneous utilization of Ti-SBA-15 and a low-cost, environment friendly oxidant - hydrogen peroxide in the epoxida‐ tion of AGE, makes this method of DGE production a modern and environment friendly as the only product of hydrogen peroxide transformation is water and Ti-SBA-15 can be easily recovered from reaction mixtures, recycled into the process, and regenerated if it loses its activity [20]. An additional advantage is this process can be carried out in an aqueous medium

124 Advanced Catalytic Materials - Photocatalysis and Other Current Trends

**2. The titanium silicate materials used for diallyl ether and allyl-glycidyl**

Until now, only the TS-1 and Ti-MWW titanium silicate materials have been used in the epoxidation of DAE and AGE – with hydrogen peroxide. In the studies performed by Wu et al. [19], AGE was the semi-product which was formed during DAE epoxidation and it underwent among others further transformation to DGE. In the above mentioned research, at the first stage, the epoxidation of DAE with hydrogen peroxide was performed under vigorous stirring in a 20 ml glass flask, connected to a condenser. In the typical run, the appropriate amounts of DAE, solvent (acetonitrile, acetone, water, methanol, ethanol, dioxane), and the catalyst were mixed in the flask and heated to the desired temperature under the agitation. Next, aqueous hydrogen peroxide (30 wt%) was added to the mixture to start the reaction. The reaction was carried out at the temperature of 60°C for 0.5 h in case of Ti-MWW and for 1.5 h in case of TS-1. Both Ti-MWW and TS-1 materials showed different solvent effect. During the examinations over Ti-MWW catalyst, the highest conversion of DAE was obtained for acetonitrile (about 40 mol%) and acetone (about 39 mol%) as the solvents. The selectivity of AGE was the highest for acetonitrile, methanol, ethanol, and dioxane and amounted to about 71–79 mol%. The selectivity of DGE, which was formed as the product of AGE transformation (epoxidation of the next double bond), was the highest for water as the solvent (about 40 mol %). High values of the selectivity of this product also allow to obtain such solvents as: acetonitrile (about 29 mol%) and acetone (about 25 mol%). The efficiency of hydrogen peroxide conversion was the highest for examinations in acetonitrile (about 95 mol%), acetone (about 92 mol%), and dioxane (about 94 mol%). In methanol and in water, the efficiency of hydrogen peroxide conversion amounted to about 82–87 mol%. The lowest value of this function of the

also.

**ether epoxidation [19]**

During the studies over the TS-1 catalyst, the highest conversion of DAE was obtained in acetone, methanol, and ethanol as the solvents. The selectivity of AGE was usually high and amounted to about 61–89 mol%. This function was the highest for dioxane. The highest values of DGE selectivity were obtained for acetone and methanol: about 22 and 21mol%, respectively. Efficiency of hydrogen peroxide conversion was the highest for acetone and amounted to 70 mol%. The studies over the TS-1 material showed that methanol and acetone were the most effective solvents in this process. The comparison of the results of DAE epoxidation present that Ti-MWW material was more efficient than TS-1 material in catalytic activity, epoxide selectivity, and hydrogen peroxide conversion when choosing acetonitrile or acetone as the solvent [19].

At the second stage, in which only Ti-MWW material was used, also the influence of temper‐ ature from 0 to 67°C was tested in the epoxidation of DAE over the Ti-SBA-15 material. The studies were performed in acetone and at the same conditions as in the first stage of these studies. The examinations showed that the selectivities of AGE and DGE changed of about 10 mol% during the rising of temperature (the selectivity of AGE from about 80 to about 70 mol %, and the selectivity of DGE from about 20 to 30 mol%). Conversion of DAE reached 40 mol % above the temperature of 60°C. The efficiency of hydrogen peroxide conversion slightly decreased with increasing temperature as a result of the thermal decomposition of hydrogen peroxide, but the value of this function was higher than 95 mol% [19].

At the third stage, the influence of the Ti-MWW amount and reaction time were studied. The examinations were performed in acetonitrile and at the temperature of 60°C. The studies showed that the more the catalyst was used, the higher the catalytic activity of Ti-MWW material. The DAE conversion raised rapidly within 30 min and then gradually with the time. The decrease in the reaction rate for longer time was mainly caused by the pore blocking by heavy organic species [19].

The comparison of the results obtained for Ti-MWW and TS-1 catalysts show that Ti-MWW material exhibited more benefits in catalytic activity using less harsh reaction conditions [19].
