Effects of alkaline-earth metals on CoMn-based catalysts for the Fischer–Tropsch synthesis to olefins

The effects of various alkaline-earth metals (Mg, Ca and Ba) on CoMn nanocatalysts for the Fischer–Tropsch synthesis to olefins (FTO) were investigated. Methane formation and second hydrogenation of olefins were suppressed effectively by the addition of alkaline-earth metals, while the olefin formation was enhanced. In addition, alkaline-earth metals can promote the carbon chain propagation to form higher hydrocarbon products, especially for long-chain olefins. Structure characterization results suggested that alkaline-earth metals with higher surface basicity would benefit the carburization of CoMn to form more Co2C nanoprisms for olefin formation.