Reducing particulate emissions by using advanced engine oil nanoadditives based on molybdenum disulfide and carbon nanotubes

Abstract

Nanoadditives can be used to enhance lubricating properties of engine oils. Although many additives have been developed, molybdenum disulfide and carbon nanotubes have attracted significant attention. In this study, we demonstrate that hybrid nanostructures based on these unique materials (MoS2/CNTs) positively affect engine oil lubricating properties. Hybrid nanostructures were produced via wet chemical synthesis in impinging jet reactor. This method is characterized by easy scalability and possible continuous operation, which are crucial in material commercialization. The application of 0.5 wt% suspension exhibited the best results, reducing the friction coefficient at the engine operating temperature by up to 26%. Nanoadditives protected the lubricated parts, causing their wear to be considerably lower than the base oil. The effect of nanoadditives on the quality of exhaust gases was also investigated, which has not yet been researched. The application of the oil with MoS2/CNT reduced the emissions of solid particles in the gasoline engine exhaust gas. The total volume of particles in the exhaust gas was reduced by 91% and 49% under idling and load-running conditions. This research showed that MoS2/CNTs can be successfully used as nanoadditives in engine oils for improving tribological properties, enhancing anti-wear performance, and reducing particle emissions in exhaust gas.