Effect of the nature of coke-forming species on the crystallographic characteristics and catalytic properties of metal-filamentous carbon catalysts in the selective hydrogenation of 1,3-butadiene

The particle morphology and surface structure of nickel metal in metal-filamentous carbon catalysts were found to depend on the nature of coke-forming species used in the synthesis of catalysts. Metal carbonization with hydrocarbons that are characterized by high thermodynamic stability results in the formation of well-cut metal particles the surface of which is formed by (110) facets. Selective hydrogenation reactions of diene and acetylene hydrocarbons to olefins are typical of these catalysts. In the catalytic decomposition of hydrocarbons with relatively low thermodynamic stability, metal particles become irregular in shape, and their surface is formed by (111) facets. In this case, the reactions of full hydrogenation of olefin, diene, and acetylene hydrocarbons to corresponding alkanes take place. These data are consistent with the found dependence of the catalytic properties of catalysts on the character of the exterior faceting of active metal particles.