Synthesis of Filamentary Carbon Material on a Self-Organizing Ni–Pt Catalyst in the Course of 1,2-Dichloroethane Decomposition

Abstract

A series of model microdisperse Ni_1–xPt_x alloys (x =0–0.05) was synthesized by a coprecipitation method with the subsequent sintering of the precipitate in an atmosphere of H₂ at 800°C. Their chemical and phase compositions were determined (by AAS and XRD analysis, respectively), and it was found that the synthesis method proposed afforded Ni–Pt solid solutions based on the face-centered nickel lattice. The kinetic features of the carbon erosion of Ni_1–xPt_x alloys in their contact with 1,2-dichloroethane vapor in a temperature range of 550–700°C were studied. It was found that the presence of Pt in the alloy increased the rate of accumulation of carbon product by a factor of ~1.5 regardless of the concentration of Pt. The catalyst did not undergo deactivation for 5 h of reaction to ensure a high yield of carbon material (103 g/g_Cat). With the use of electron microscopy (SEM and TEM techniques), it was found that the carbon product consisted of carbon fibers with a segmented structure. An increase in the concentration of Pt in the alloy to 4.3 wt % sharply changed the disintegration of the alloy to cause the formation of carbon product with a bimodal fiber diameter distribution (d_av = 0.4 and 1.2 μm).