Multi-walled carbon nanotubes coated on defective tungsten oxide for deep oxidative desulfurization of diesel fuels

Abstract

The interface properties of metal oxides considerably affect the catalyst activity during the removal process of persistent organic sulfur pollutant in diesel fuels. Herein, we report that the hydrophilicity of defective metal oxides can be well shielded by refining the interface. As a proof of point, multi-walled carbon nanotubes (CNTs) were employed as a solid modifier to be wound on the Mo-doped W18O49 nanowire clusters (MoWO-x@CNTs) for enhanced catalytic performance. The results show that the full conversion of dibenzothiophene is achieved within 12.5 min. The turnover frequency value is up to 79.7 h−1, much higher than other catalysts. Compared with the bare W18O49, the MoWO-x@CNTs exploits a rough hierarchical structure, which overcomes the limitation of the hydrophilic W18O49 interface. Furthermore, the persistent organic sulfur in diesel fuels is <6.2 ppm, achieving the goal of ultra-deep desulfurization. Besides, no more secondary extraction is required, which also alleviating environmental pollution caused by the abuse of organic waste.