Direct synthesis of higher oxygenates via syngas over zinc oxide modified CoMn-based catalysts.

Controlling product selectivity still remains as a grand challenge for syngas conversion to fuels and chemicals. Herein, ZnO modified CoMn-based catalysts were prepared for direct higher oxygenates synthesis via syngas conversion, and the role of Zn promoter on catalytic behaviour and structure evolution was investigated comprehensively. It was found that the addition of Zn greatly reduced the particle size of active phases including Co and Co 2 C. Specially, the Zn promoter facilitated the formation of Co 2 C species, thus effectively tuning the surface ratio of Co/Co 2 C and strengthening the function for CO associative adsorption and insertion for oxygenates product formation. As a result, the oxygenates selectivity was enhanced to 39.1 wt% over ZnO-promoted CoMn-based catalyst, where more than 96.0 wt% of the produced oxygenates are C 2+ products. In addition, Zn promoter can weaken the chain growth ability, leading to the increase of low carbon chain products. [Display omitted] • The addition of Zn promoter greatly reduced the particle size of Co and Co 2 C. • Zn promoter facilitated the formation of Co 2 C. • CO associative adsorption was strengthened for oxygenates formation with Zn addition. • The selectivity of oxygenates was enhanced to 39.1 wt% for Zn-promoted CoMn-based catalyst. [ABSTRACT FROM AUTHOR]