Binding and activation of ethylene on tungsten carbide and platinum surfaces

       Because of its excellent physical properties, tungsten carbide is widely used in many industries, even some industries that you might not expect. As a professional tungsten carbide spraying manufacturers, Chengdu Oriental Taiping industrial Co., Ltd. for tungsten carbide scientific research and manufacturing strength is relatively strong. Today we introduce a study of tungsten carbide: the binding and activation of acetylene on the surface of tungsten carbide and platinum.







Binding and activation of ethylene on tungsten carbide and platinum surfaces







Density functional calculations were used to evaluate the ability of the cubic and hexagonal phases of tungsten carbide to bind ethylene as a model compound for unsaturated hydrocarbons, since its adsorption is the first step in an important catalytic process.







The stability trend is as follows: α-WC (0001) -C>α-WC (0001) -W> Pt (111) >γ-WC (001), and the binding energy varies from -0.72 to -2.91 eV. The subsurface layer plays a crucial role in bonding, facilitating charge recombination in the extended range from volume to surface (greater than 6A), but the surface electronic structure is modified only at the topmost layer.







The surface position of geometry C 2 H 4 identifies activation, resulting in surface deformation, due to the upward movement of surface atoms observed in Pt (111), α-WC (0001) -C, and γ-WC (001) in the range 0.13 -- 0.61a due to energies of 0.13, 0.15, and 0.61 eV, respectively.







The activation of C 2 H 4 on tungsten carbide is compared with other transition metal carbide surfaces, which divides the general classification of carbon-carbon bond extension into only three groups. If the interest is in activating the ethylene C[double bond, length M-dash]C bond, the surface site and binding mode should be group II and III. The INFRARED spectrum mainly shows four useful signals as fingerprints to support and complement future experiments.







The results of this work suggest that α-WC-W surfaces may directly affect catalytic performance, and the binding of alkenes to α-WC-C may lead to surface toxicity. Compared to known α-WC (0001) surfaces, metastable γ-WC (001) surfaces may be a promising system, but challenges arise in terms of synthesis, stability, and catalytic performance. These results pave the way for further experimental and theoretical studies focusing on the hydrogenation of ethylene and more complex unsaturated hydrocarbons.