Rivet-like iron oxide nanoparticles and their catalytic effect on extra heavy oil upgrading

In this paper, rivet-like iron oxide nanoparticles were synthesized via a one-pot hydrothermal method for the first time. SEM and TEM results demonstrated that the as-prepared rivet-like nanoparticle consisted of two parts, a head part with an average size of 50 nm, and a tail one with a diameter of 20–40 nm and a length of ca. 100 nm. XRD result revealed that this nanoparticle had a dominant hematite phase and minor goethite phase. The rivet-like iron oxide nanoparticles exhibited higher catalytic activity for the upgrading of Shengli-oilfield extra heavy crude oil than the cubical α-Fe2O3 nanoparticles in the absence of hydrogen donors. In particular, owing to the site-rich surface of the catalyst, the viscosity of the Shengli extra heavy oil decreased from 244520 mPa∙s to 152000 mPa∙s (at 50 °C) in the presence of the 400 °C-treated nanoparticles after the reaction at 200 °C for 24 h. Higher exposure of (1 0 4) facet could possibly also account for the higher catalytic activity.