Efficient oxidative desulfurization of high-sulfur petroleum coke over polyoxometalates HPA coupled CeO2

High-sulfur petroleum coke (HSPC), produced during petroleum coking process, has drawn ever increasing attention in the manufacture of graphite electrodes with the rise of new energy vehicles in recent years. However, its high sulfur content ( S > 3.0 wt.%) has become the major obstacle limiting this promising application. Herein, an innovative method is proposed to effectively lower the content of sulfur in HSPC through a series of polyoxometalate H 11 P 2 W 13 V 5 O 62 (HPA) coupled CeO 2 . The experimental results unveiled that the sulfur compounds in HSPC predominately existed as thiophene and mercaptan sulfur compounds, which could be oxidized to be the corresponding sulphone, sulphoxide and sulphate species. Moreover, the introduction of CeO 2 considerably promoted the dispersion of HPA, thereby exposing more reactive sites for the adsorption and activation of H 2 O 2 to produce active oxygen species, and thereafter endowing x%HPA@CeO 2 ( x = 20∼40) with excellent catalytic oxidative desulfurization (ODS) performance for HSPC. As a result, the sulfur content was significantly reduced from 4.46 wt.% to 2.12 wt.% at 70 °C and reaction time of 4 h due to the coupling effect between HPA and CeO 2 over 30%HPA@CeO 2 . The present study not only provides an innovative technological path for the efficient removal of sulfur from HSPC, but also promotes the understanding of catalytic ODS process of HSPC on the catalyst surface active centers.