III International Conference

PP-I-44HYDROGENATION of CARBON OXIDES OVER Ni-, Fe- AND Cu – ULTRAFINECATALYSTSSerov Y.M., Sheshko T.F., Nikonorova E.V.Peoples Friendship University of Russia, Moscow, RussiaE-mail: serov@sci.pfu.edu.ru, sheshko@bk.ruThe activity of the catalysts on the base of Ni –, Fe - and Cu- ultrafine powders havebeen investigated for carbon oxides simultaneous hydrogenation.Carbon oxides simultaneous hydrogenation at atmospheric pressure over the catalystscontaining nano-particles of nickel, iron and copper, and also interaction of carbon oxideswith a surface of ultrafine powders of metals is studied.Carbon oxides simultaneous hydrogenation proceeds through stages of dissociativeadsorptions both of mono- and bi-oxides of carbonСО → С ad + О adСО 2 → СО + О ad ; СО → С ad + О adIt is complicated by reaction of CO disproportionation:2СО → СО 2 + С.The quantitative ratio between these reactions is defined both by concentration ofhydrogen on a surface of the catalyst, and temperature of process.It is established, that the basic products of joint carbon oxides hydrogenation are methaneand ethylene, and in the lack of hydrogen - methane, ethane and ethylene, propane andpropylene. Selectivity to alkenes reached 35 % over the studied nano-catalysts. Upon theadsorption of hydrogen on the metals, capable to dissolve them, there are two forms on asurface, one of which is bonded only with one atom of metal (Н I ), and another - strongadsorbed(H II ) - with several. Formation of hydrocarbons proceeds through a stage offormation of active carbon, however selectivity of the process to alkenes, possibly, is definedby ratio Н I : Н II on a surface of the catalyst. Increase of concentration of hydrogen in the formof Н II increases output of alkenes.Apparently, on a surface of bimetallic samples there are some types of the active centersresponsible for formation CH 2 -radicals - iron or copper, hydrogen sorption on which proceedsmainly in the molecular form. Atomic hydrogen formed as a result of dissociativechemisorption on the nickel centers bonds active carbon particles with formation of methane,and oxygen - with formation of water. CH 2 -radicals formed on copper centers can be87