Review of Molybdenum Disulfide Research in Slurry Bed Heavy Oil Hydrogenation

With the growing demand for gasoline and diesel fueland the shortageof conventional oil reserves, there has been extensive interest inupgrading technologies for unconventional feedstocks such as heavyoil. Slurry bed reactors with high tolerance to heavy oil have beenextensively investigated. Among them, dispersive MoS2 isfavored for its excellent hydrogenation ability for heavy oil evenunder harsh reaction conditions such as high pressure and high temperature,its ability to effectively prevent damage to equipment from depositedcoke, and its ability to meet the requirement of high catalyst dispersionfor slurry bed reactors. This paper reviews the relationship betweenthe structure and hydrogenation effectiveness of dispersive molybdenumdisulfide, the hydrogenation mechanism, and the improvement of itshydrogenation performance by adding defects and compares the applicationof molybdenum disulfide in heavy oil hydrogenation, desulfurization,deoxygenation, and denitrification. It is found that the current researchon dispersive molybdenum disulfide catalysts focuses mostly on thereduction of stacking layers and catalytic performance, and thereis a lack of research on the lateral dimensions, microdomain regions,and defect sites of MoS2 catalysts. The relationship betweencatalyst structure and hydrogenation effect also lags far behind theapplication of MoS2 in the precipitation of hydrogen, etc.Oil-soluble and water-soluble MoS2 catalysts eventuallyneed to be converted to a solid sulfide state to have hydrogenationactivity. The conversion history of soluble catalysts to solid-typecatalysts and the key to their improved catalytic effectiveness remainunclear.