Catalytic Properties of Bulk (1–x)Ni–xW Alloys in the Decomposition of 1,2-Dichloroethane with the Production of Carbon Nanomaterials

Abstract

Abstract: This work was devoted to a search for effective catalysts for the processing of chlorine-substituted hydrocarbons to obtain carbon nanomaterials. A series of porous (1–x)Ni–xW nanoalloys with tungsten concentrations from 0.5 to 10 wt % was synthesized by a coprecipitation method. All of the samples were single-phase solid solutions based on a face-centered cubic (fcc) lattice of nickel and had a spongy structure. The kinetics of carbon erosion of bulk (1–x)Ni–xW alloys in the course of interaction with a reaction atmosphere containing 1,2-dichloroethane vapor at 600°C was studied. This process was accompanied by rapid disintegration of the alloys with the formation of active particles for the growth of carbon nanofibers (CNFs). The addition of tungsten led to an increase in the activity of nickel in the synthesis of CNFs by 10–70%. The highest yield of CNFs for 2 h of reaction (29.8 g/gNi) was observed with a Ni–W alloy (4 wt %). The structural and morphological features of the resulting carbon product were investigated. Electron-microscopic data indicated the formation of carbon filaments with a pronounced segmented structure. Raman spectroscopy data revealed that the addition of tungsten decreased the fraction of amorphous carbon in the product. According to the data of low-temperature nitrogen adsorption, the specific surface area of the carbon nanomaterial was 300–400 m2/g.