4
RUDN University Chemist created a niobium-silica catalyst to boost petrochemical reactions

RUDN University Chemist created a niobium-silica catalyst to boost petrochemical reactions

Alkylation reactions are used in the petrochemical industry to obtain high-octane number components for gasolines. A chemist from RUDN University found a way to speed this process up to 24 times. To do so, he developed a catalyst based on silica and niobium. The results of his work were published in the Molecular Catalysis journal.

In the course of alkylation, an atom of hydrogen in an organic compound is replaced with other substances, the so-called alkylating agents. Alkylation is used in the chemical and petrochemical industries, for example, to obtain high-octane number components in gasolines. For the process to go on quickly and efficiently, it needs catalysts including mineral acids and zeolites—minerals that are capable of selectively releasing substances and then adsorbing them back. However, mineral (e.g. sulphuric or phosphoric) acids can be expensive and dangerous: in order to extract them from the reaction mix, one needs additional reagents that can be hard to handle. Unlike mineral acids, zeolites are safe and cheap to produce. The only problem lies in their microporous structure that limits the size of the molecules they can react with. A chemist from RUDN University created a catalyst that is free from these disadvantages and able to speed up the alkylation reaction up to 24 times. To do so, his team used niobium and SBA-15, a mesoporous ordered form of silica.

“SBA-15 materials are relevant as catalytic support due to their high surface area and pore volume in the mesopore range that convert it in an outstanding catalyst support. We aimed to evaluate the acidity of several Al-SBA-15 supported niobium oxide catalysts prepared by a mechanochemical protocol with different metal loadings,” said Rafael Luque PhD, the head of the Molecular Design and Synthesis of Innovative Compounds for Medicine Science Center at RUDN University.

The team paid attention to the reductive-oxidative and acidic properties of niobium-based compounds that are important for a catalyst and decided to test niobium in an alkylation reaction. To do so, they put niobium oxide nanoparticles (that had been mechanochemically ground down to several nanometers in size) on the support. The metal content in the new material varied from 0.5% to 1% and the size of the particles was controlled with a transmission electron microscope. The team used energy-dispersive X-ray spectroscopy to secure even distribution of particles across the surface of the support.

To analyze the catalytic properties of the new material, the chemists carried out the reaction of toluene alkylation with benzyl alcohol and benzyl chloride that acted as alkylating agents. As a result of the experiment, the team confirmed a positive effect of niobium particles on the reaction: its time of reaction reduced from 4 hours to 10 minutes. The catalyst with lower niobium content (0.5%) turned out to be more effective due to better dispersion. The team believes that when the catalyst was synthesized, niobium oxide deposited on the support, and the more niobium, the bigger the catalyst particles turned out to be. This reduced the effective contact area of the particles and therefore had a negative impact on the material’s catalytic activity.

“We managed to create a catalyst that reduces the time of alkylation reactions from several hours to just 10 minutes, is free from the chemical limitations of zeolites, and poses no danger unlike mineral acids,” added Rafael Luque.

The article was published in Molecular Catalysis.

International Projects View all
International scientific cooperation View all
16 Oct
530 applications, 90 young scientists from 30 countries. Darya Nazarova, a postgraduate student of RUDN Faculty of Economics, traveled 11,276 km from Moscow to Sao Paulo for the International Scientific School on Technological and Innovation Strategies and Economic Development Policy at the University of Campinas (UNICAMP). Darya Nazarova, a young RUDN scientist, writes about scientific research, rafting and the country of eternal carnival.
45
Similar newsletter View all
16 Oct
Green Diplomacy Center opened in RUDN

A Center for Green Diplomacy was created based on the RUDN Institute of Environmental Engineering. Among the goals is the integration of the results of scientific and practical activities into the development of international relations in the environmental sphere. The center's specialists will also accompany the corporate sector in solving various environmental problems.

67
19 Apr
A huge pizza and a jug of water, why should 5G networks be sliced? The winners of RUDN science competition explain

RUDN summarized the results of the scientific competition "Project Start: work of the science club ". Students of the Faculty of Physics, Mathematics and Natural Sciences have created a project for a managed queuing system using a neural network to redistribute resources between 5G segments. How to increase flexibility, make the network fast and inexpensive and reach more users — tell Gebrial Ibram Esam Zekri ("Fundamental Computer Science and Information Technology", Master's degree, II course) and Ksenia Leontieva ("Applied Mathematics and Computer Science", Master's degree, I course).

151
19 Apr
Lyricists and physicists are now on equal terms: the first humanitarian laboratory opened in RUDN

What is your first association with the word “laboratory”? Flasks and beakers? Microscopes and centrifuges? Yes, many of us would answer the same way.

196
Similar newsletter View all