Preparation and characterization of Ni–Co/SiO2 nanocomposite catalysts for CO2 methanation

• Published in: Applied nanoscience Vol. 12; no. 3; pp. 349 - 359
• Main Authors: Dyachenko, Аlla G., Ischenko, Olena V., Goncharuk, Olena V., Borysenko, Mykola V., Mischanchuk, Olexandr V., Gun’ko, Volodymyr M., Sternik, Dariusz, Lisnyak, Vladyslav V.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.03.2022; Springer Nature B.V
• Subjects: Bimetals; Carbon dioxide; Catalysts; Catalytic activity; Chemical reduction; Chemistry and Materials Science; Cobalt; Crystallites; Materials Science; Membrane Biology; Methanation; Methane; Nanochemistry; Nanocomposites; Nanotechnology; Nanotechnology and Microengineering; Original Article; Silicon dioxide; Thermal decomposition; X ray powder diffraction; Nanocomposite catalysts; Catalytic CO; Incremental PSDs; methanation; Thermal desorption; Cobalt and nickel NPs; Nanosilica
• ISSN: 2190-5509; 2190-5517
• DOI: 10.1007/s13204-020-01650-1

For effective CO 2 methanation, monometallic Co(10)/SiO 2 and Ni(10)/SiO 2 and bimetallic Ni(5)Co(5)/SiO 2 and Ni(2)Co(8)/SiO 2 nanocomposite (NC) catalysts, where numbers between brackets indicate the metal content (wt%), have been prepared with solvate-stimulated modification, thermal decomposition, and chemical reduction stages using nanosilica A-300 as a carrier. The catalysts were characterized using SEM–EDX, nitrogen physisorption, and X-ray powder diffraction. The samples before and after the reduction with hydrogen have a similar mesoporous texture. The bimetallic Ni–Co/SiO 2 NC catalysts showed improved catalytic activity compared to Ni/SiO 2 . The formers are characterized by the smallest bimetallic crystallites of ca. 12 nm in size. Activity in the methanation of the Ni–Co/SiO 2 NC catalysts depends on the cobalt content resulting in a prominent increase in CO 2 conversion and methane yield at 250–350 °C. The SEM–EDX analysis showed unusual flower-like nanostructures and proved the random distribution of Ni/Co bimetallic aggregates in the nanosilica matrix at the nanoscale level. Both Ni(2)Co(8)/SiO 2 and Ni(5)Co(5)/SiO 2 exhibited high activity in the CO 2 methanation with 81–88% CH 4 yield at 450 °C. The results of thermo-programmed desorption mass spectroscopy revealed that the catalytic reaction is passed through the formation of O-containing intermediates bound to the active Ni–Co and nanosilica sites.