Response to Comment on Oil-Dispersed α-Fe2O3 Nanoparticles as a Catalyst for Improving Heavy Oil Oxidation

Abstract

The main goal of our previous work was to study the effect of coating the hematite (α-Fe2O3) particles with oleic acid on their catalytic properties for improving heavy oil oxidation (https://doi.org/10.1021/acs.energyfuels.1c00657). We concluded that “Compared with α-Fe2O3, α-Fe2O3@OA more efficiently catalyzed the combustion of heavy oil due to its good dispersion in heavy oil. α-Fe2O3 was found to be transformed into smaller size magnetite (Fe3O4), maghemite (γ-Fe2O3), and α-Fe2O3 during heavy oil combustion process. These enhanced performances in the heavy oil combustion by α-Fe2O3@OA could be favorable for improving the efficiency of the in situ combustion (ISC) technique in oilfields”. This conclusion was obtained on the basis of a joint analysis of the data of several experimental methods and techniques, such as porous medium thermo-effect cell (PMTEC) and thermogravimetry–infrared spectroscopy (TG–FTIR) experiments, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Mössbauer spectroscopy. Recently, Pranaba K. Nayak claimed that the choice of Mössbauer spectroscopy was excellent but the inability to extract a great deal of information from the carefully obtained Mössbauer spectra makes the study and its subsequent discussion of not much use. In this response, we reiterate that the phase identification in our previous paper by Mössbauer spectroscopy was carried out correctly and the phase components were determined with good statistical accuracy.