Effect of Pd content in multi-component alloys [CoFeNi]Pdx on their behavior in hydrocarbon-containing atmosphere

Abstract

Multicomponent metal systems attract growing interest today, especially as catalysts for various processes. In the present work, a series of [CoFeNi]Pdx alloys (equal atomic content of base metals) doped with palladium in the amount of 0–10 at.% were synthesized via thermolysis of multicomponent precursors. The resulting [CoFeNi]Pdx alloys were found to be single-phase solid solutions with a fcc structure represented by agglomerates of grains fused. The performance of the alloys was explored in a mixture of saturated hydrocarbons (C2–C4) within the temperature range of 600–675 °C. As a result of interaction with the reaction mixture, spontaneous disintegration of the alloys containing above 2 at.% Pd occurs with the formation of dispersed particles responsible for the catalytic growth of carbon nanofibers (CNF). The dependence of the productivity of the [CoFeNi]Pdx alloys towards CNFs on the x parameter was studied. The highest CNF yield (YC = 25–46 g/gcat, 30 min) was achieved at an optimal Pd concentration of 8 at.% within the entire temperature range. According to TEM and EDX data, regardless of the reaction temperature and Pd concentration in the alloy, the catalyst particles have the same composition as defined at the synthesis of the alloys. The resulting CoFeNiPd@CNF composite can be considered as a catalyst for other heterogeneous catalysis processes.