RUDN University chemist discovered a way to quadruple the speed of toluene photooxidation
RUDN University chemist discovered a way to quadruple the speed of toluene photooxidation
A chemist from RUDN University has proposed a new way to control toluene photooxidation using composite catalysts — artificial diamond and titanium dioxide. The discovery refutes the previously existing physical hypothesis about the process of photooxidation of toluene.

Toluene is a combustible liquid that is extracted from gasoline fractions of oil for the production of paint materials, chemicals, solvents, and aviation fuel. Benzaldehyde and carbon dioxide are produced during the photooxidation of toluene. Benzaldehyde is used to produce benzoic acid, an important element in the production of food preservatives, medicines, and chemical raw materials. However, the widespread industrial photooxidation of toluene with oxygen into benzoic acid is a slow process. RUDN University chemist proposed a new way to control the photooxidation of toluene using catalysts g-C3N4/TiO2 and manganese (Mn), increasing the reaction rate 4.3 times and increasing the efficiency of benzaldehyde production.

Rafael Luque from the Research Institute of Chemistry of RUDN University notes that only benzaldehyde and carbon dioxide are found as reaction products for all solids without significant differences between composite samples. And their reference catalyst based on titanium dioxide is highly active and converts the partial oxidation product mainly into benzaldehyde, increasing the efficiency of the reaction.

The chemists conducted a combination of adsorption and kinetic studies. They developed evidence that the reaction occurs by a hydroxyl-mediated mechanism – it means that the increase in the activity of the elements depends on changes in the rate of formation of hydroxyl particles that are present on the surface of solids.

Scientists have found that the reaction rate is quantitatively related to the rate of production of hydroxyl particles, which interact with toluene affect the process of photooxidation. This means that regulating the contact between the components allows controlling the rate of photoactivity.

Scientists found that the new catalysts increase the reaction rate of toluene photooxidation by about 2.5 times, and the addition of manganese to the carbon nitride component shows a further increase in the reaction activity by 1.8 times. That is, the contact between the components of the composite catalyst g-C3N4/TiO2 significantly improves the photooxidation of toluene, and manganese enhances such a beneficial effect.

Thus, chemists have found that the contact between the components allows you to control the rate of photoactivity by slowing or accelerating the process of photooxidation of toluene. The authors of the study report that the findings refute the previously existing hypothesis in the scientific literature about the nature of the photooxidation process.

Rafael Luque, Director of the Scientific Center of the Research Institute of Chemistry of RUDN University, conducted research in collaboration with colleagues from leading institutions in Spain (universities of Madrid, Granada, Cordoba).

The article is published in the Chemical Engineering Journal.

News
All news
Science
20 Oct
RUDN chemist created an efficient catalyst for organic sulfides synthesis

A RUDN chemist has obtained a new compound — a dumbbell-shaped phosphate-bridged molybdenum cluster. The cluster accelerates the reaction of the formation of sulfides from oxides and can be used in pharmaceutical and cosmetic manufacturing.

Science
19 Oct
RUDN University mathematicians created a method for study the properties of porous materials

Mathematicians from RUDN University have studied the properties of compositional operators in spaces with mixed Lebesgue norms. It will help describe the diffusion of liquids in materials with cracks and in porous materials. Such spaces are also useful for obtaining estimates for solutions to the Navier-Stokes equation.

Science
09 Oct
RUDN University biophysicist modelled the behaviour of cell microtubule elements to chemically affect their growth and decay

A biophysicist from RUDN University and his colleagues modelled the molecular dynamics of growth of microtubules, the most important elements of cell activity. The researchers have built a model for the interaction of microtubule subunits, which takes into account their internal and external connections. The results will help form a more complete model of the dynamic instability of microtubules. It will allow choosing chemical agents for the treatment of certain diseases, including neoplasms and neurodegenerative pathologies.