Nanocomposites and nanomaterials

Nanocomposites NiFe(CoFe)/Silica(Alumina) for the catalytic hydrogenation of CO2 
А. Dyachenko2,3, O. Ischenko1, O. Prygunova1, M. Borysenko2, 
M. Bonarowska3
1Taras Shevchenko National University of Kyiv, 64/13 Volodymyrs’ka Str, Kyiv, 01601, Ukraine
2O.O. Chuiko Institute of Surface Chemistry National Academy of Science of Ukraine, 17 General Naumov Str, Kyiv, 03164, Ukraine
3Institute of Physical Chemistry of Polish Academy of Sciences, 44/52 Kaspzaka, 01-224  Warsaw, Poland.
E-mail: dyachenko.alla@yahoo.com

Nanocomposite materials on the base of Silica or Alumina with NiFe or CoFe bimetallic nanoparticles localized on the surface of them have a high potential for the use as catalysts in the process of CO2 hydrogenation. It was observed that a high specific surface area of the carrier (200-300 m2/g) causes an uneven distribution of active mass components on the carrier surface and does not contribute to the formation of catalytically active sites and as a consequence the efficient conversion of CO2 to methane [1,2].
The aim of this study was to determine the catalytic activity of nanocomposites with a specific surface area of about 80 m2/g. The fumed oxides (SiO2 and Al2O3) were used for the synthesis of NCs as the carriers, and catalytically active bimetallic compositions (NiFe and CoFe) were applied on the surface by the method of solvatostimulated modification with subsequent processes of thermal degradation and reduction.
The long-time catalytic test demonstrates the high stability of the catalyst during 5 weeks of exposure to the reaction mixture. Catalytic reactor worked in the next mode: 8 hours of working in the methanation process at temperature range 350-450 °C then the catalyst was kept under reaction mixture at room temperature for 1 week. This cycle was repeated 3 times for each catalyst. The yield of methane was decreased on 11-15% after a long time test.

1.	A.G. Dyachenko, O.V. Ischenko, O.V. Goncharuk, M.V. Borysenko, et al. Preparation and characterization of Ni–Co/SiO2 nanocomposite catalysts for CO2 methanation // Appl. Nanosci. – 2022. -12. – P.349-359
2.	A. Dyachenko, O. Ischenko, V. Diyuk, O. Goncharuk, et al. The catalytic efciency of Fe‑containing nanocomposites based on highly dispersed silica in the reaction of CO2 hydrogenation // Res. Chem. Inter. https://doi.org/10.1007/s11164-022-04720-x (2022)