IMPROVED CATALYST FOR PRODUCING MULTILAYER CARBON NANOTUBES Russian patent published in 2024 - IPC B01J21/04 B01J23/22 B01J23/75 B01J23/847 B01J23/88 B01J37/04 B01J37/08 C01B32/158 C01B32/162 H01M4/96 

FIELD: chemistry.

SUBSTANCE: present invention relates to a supported catalyst system for converting hydrocarbons into carbon nanotubes and, in particular, to a system of an iron-free catalyst on a support for a process of producing multilayer carbon nanotubes with improved selectivity and output. Described is a supported iron-free catalyst for selective conversion of hydrocarbons into carbon nanotubes, wherein said catalyst contains cobalt and vanadium as active catalytic metals in any oxidation state on a catalyst support, containing at least 30 wt.% aluminum hydroxide based on the total amount of aluminum hydroxides and/or aluminum oxides and aluminum oxide hydroxide, as determined by X-ray diffraction method, where: weight ratio of cobalt to vanadium is from 2 to 15; weight ratio of cobalt to aluminum ranges from 5.8×10⁻² to 5.8×10⁻¹; weight ratio of vanadium to aluminum ranges from 5.8×10⁻³ to 8.7×10⁻². Method of producing said supported iron-free catalyst includes steps of: reducing an aqueous solution, containing one or more polycarboxylic acids and/or salts of polycarboxylic acids, in contact with one or more vanadium-based precursors; bringing one or more cobalt-based precursors into contact with an aqueous solution containing vanadium-based precursors to form a mixture of water-based catalytic precursors; bringing aluminum hydroxide, having BET (Brunauer–Emmett–Teller specific surface area) in range of 3 to 18 m²/g, in contact with a water-based mixture containing catalytic precursors, to form a mixture of water-based aluminum hydroxide and catalytic precursors; drying the water-based mixture of aluminum hydroxide and catalytic precursors to form a dried mixture; calcining the dried mixture at temperature of 200–600 °C to form a calcined product containing at least 30 wt.% aluminum oxide hydroxide in terms of total amount of aluminum hydroxides and/or aluminum oxides and aluminum oxide hydroxide, as determined by X-ray diffraction method; calcined product is milled to powder. Method of producing multilayer carbon nanotubes from said supported iron-free catalyst comprises the steps of: loading the catalyst into a reactor; heating the catalyst to temperature of 500 to 900 °C; supplying a carbon source to the reactor while maintaining temperature of 500 to 900 °C; bringing the catalyst into contact with the carbon source for a period of time of at least 1 minute. Disclosed are multilayer carbon nanotubes obtained using said method, which contain from 0.1 to 13 wt.% of said catalyst; polymer matrix containing said multilayer carbon nanotubes, and use of said multilayer carbon nanotubes in batteries.

EFFECT: meeting the need for multilayer carbon nanotubes obtained using the technology of catalytic chemical vapor deposition of hydrocarbons over metal catalysts, not containing iron, with improved selectivity and efficiency.

27 cl, 8 ex, 4 tbl