Russian scientists have obtained catalysts that most effectively neutralize nitrous oxide, a byproduct of chemical and agroindustry that destroys the ozone layer. In the future, the development will improve the efficiency of industrial emissions treatment systems.
The increasing concentration of greenhouse gases is one of the most serious environmental problems of our time. Among them, nitrous oxide occupies a special place, which is formed as a result of agricultural activities and the burning of fossil fuels. It does not directly harm humans, but it aggressively affects the Earth's ozone layer and contributes to global warming.
Currently, the catalytic decomposition of nitrous oxide to harmless nitrogen and oxygen has a number of technological and economic limitations. The main problems of the process are related to the high temperature of the reaction (up to 700 ° C), the multi-stage synthesis of catalysts, as well as the high cost of the initial reagents used for their preparation. Scientists from NUST MISIS, IOH RAS and Moscow State University have proposed a new solution — the use of highly active metal-containing zeolite catalysts obtained using an improved technique. The proposed approach makes it possible not only to simplify the production of the catalyst, but also to significantly increase its efficiency.
In this work, zeolite with the FER structure was obtained by two synthesis methods. The first is a classic hydrothermal method based on the synthesis of zeolite in an aqueous alkaline solution. The second is solvothermal, based on a synthesis reaction in organic solvents (pyridine and n-butylamine) with the addition of hydrofluoric acid.
"These approaches make it possible to create FER zeolites with different crystal shapes, porosity, and chemical activity. The hydrothermal method turned out to be the most effective, as it allows obtaining zeolite with a more homogeneous porous structure and a smaller particle size," said Leonid Kustov, PhD, Professor, Head of the Laboratory of Nanochemistry and Ecology at NUST MISIS, Chief Researcher at the Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences.
The details of the study are described in the scientific journal Colloids and Surfaces A: Physicochemical and Engineering Aspects (Q1).
"We also found that zeolite catalysts with cobalt additives can handle the decomposition of nitrous oxide more efficiently than their copper-based counterparts. The best cobalt catalyst achieved 90% N2O decomposition at 420°C, while copper catalysts required 50-70°C more to achieve the same result," she added. Anna Makova, Assistant Professor, Department of General and Inorganic Chemistry, NUST MISIS.
The work was supported by a grant from the Russian Science Foundation (project No. 23-73-30007).
