Iron oxide nanoparticles supported on carbon nanotubes: an efficient catalyst for water–gas shift reaction

Abstract

In this study, the water–gas shift reaction (WGSR) was investigated using a 3%FeO_x/CNT catalyst prepared by depositing iron nanoparticles on carbon nanotubes (CNT). The characteristics of the catalyst before and after WGSR were analyzed using Raman, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), which confirmed the structural stability of the nanocomposite during the reaction. The 3%FeO_x/CNT catalyst exhibited high catalytic activity and long-term stability over a wide range of steam/CO ratios (5.50 : 1–1.38 : 1). At low CO concentrations, a broad temperature hysteresis was observed, which narrowed with increasing CO concentration. Decreasing the Fe loading further supported the narrowing of the hysteresis window. Our findings demonstrate that 3%FeO_x/CNT outperforms non-promoted CNT-supported Pt- and Ni-based catalysts in terms of catalytic activity. These results suggest that nanocomposites of iron and carbon nanomaterials with low Fe loading are promising catalysts for WGSR.