Catalyst for methane vapor reforming fabricated on the basis of natural oxides and stable in H2S medium: Activity, selectivity, and nanostructure evolution

Abstract

This work presents the results of studies on the activity of an iron-nickel catalyst fabricated on the basis of mixed oxides separated from layered vermiculite in the process of methane vapor reforming. It has been demonstrated that the degree of methane transformation in the conversion process is close to the equilibrium one, whereas the catalyst manifests stability to coke formation and the presence of hydrogen sulfide in the vapor-gas mixture. The structure and phase state of the active components of the system have been investigated using the XRD and Moessbauer spectroscopy methods. It has been shown that, during the formation of the catalyst and the catalysis itself, the system surface hosts solid-phase transformations of deposited active components with iron ions present in the substrate. The formation of superparamagnetic clusters of iron oxide strongly bound to the substrate structure on the surface of the catalyst (particles of invar alloy FeNi) determined its polyfunctional properties: high activity in both methane vapor reforming and hydrogen sulfide oxidation decomposition up to elementary sulfur.