Scientists from the Efficient Catalysis Group of the A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences (Moscow) have developed a new method for carrying out reduction reactions in organic chemistry.
We are talking about the use of synthesis gas instead of pure hydrogen - a mixture of hydrogen and carbon monoxide.
The new method will simplify the production of many pharmaceuticals, complex fertilizers and other industrially important compounds.
This was reported to RT in the press service of the Russian Science Foundation (RNF).
The corresponding study was published in the journal ACS Catalysis.
Hydrogen is actively used in the chemical industry.
It has reducing properties, since it easily “gives away” its negatively charged electrons to other atoms.
As a result, molecules of new substances are synthesized.
For example, with the help of such reactions, many pharmaceuticals are created.
However, hydrogen as a reducing agent has significant disadvantages, the authors of the study note.
For example, it destroys some of the catalysts necessary for the reaction, and also has low selectivity - during synthesis it is difficult to predict which atoms the free electrons of hydrogen atoms will go to.
Autoclaves in which reactions were carried out
© Oleg Afanasiev
Scientists have found that these problems can be solved by mixing hydrogen with another reducing agent - carbon monoxide.
This substance is more selective, but not as active in reactions as hydrogen.
The mixture of gases has the necessary qualities of both substances - selectivity and activity, the authors of the work note.
Thanks to this, “synthesis gas” can greatly increase the efficiency of some reactions actively used in the chemical industry.
In addition, the introduction of this technique can reduce the cost of production, since in this case there is no need to obtain pure hydrogen.
Recall that synthesis gas is a product of the first stage of the conversion of natural gas and coal into chemical products, which itself is a raw material for producing hydrogen.
Practical studies have shown that the use of synthesis gas makes it possible to obtain a pure desired product in the amination reaction (addition of a nitrogen-containing fragment (amino group) to various molecules. -
RT
) of organic compounds.
When pure hydrogen is involved in this reaction, only 8% of the resulting substance is a useful product, and 92% is by-products.
This low efficiency is explained by the fact that hydrogen in its pure form destroys the catalyst, which ensures the correct course of the reaction.
The scientists also tested the effectiveness of syngas in another reaction using a different catalyst.
As a result, the yield of the useful substance was 64%, while as a result of a similar reaction involving hydrogen, this figure did not exceed 6%.
“Our study showed that synthesis gas is many times more efficient reducing agent than hydrogen.
This cheap industrial intermediate will simplify the synthesis of many pharmaceuticals, complex fertilizers and other industrially important compounds.
In the future, we plan to determine the optimal conditions under which synthesis gas performs its functions in the best possible way, ”explained Oleg Afanasiev, Candidate of Chemical Sciences, researcher at the Efficient Catalysis Group of the INEOS RAS.