The active pair of Coδ+/Co0 tailored by nickel and CaTiO3 with perovskite phase for higher alcohols synthesis from syngas

Abstract

Higher alcohols synthesis (HAS) from syngas (CO + H2) is much attractive, but achieving a high selectivity of alcohols is still challenging due to the difficult balance between dissociative adsorption and associative adsorption of CO. In this work, a series of Coδ+/Co0 tailored by nickel and CaTiO3 catalysts derived from a series of perovskite pre-catalyst Ca0.6La0.4Ti0.6Co0.4-xNixO3 were prepared and applied to HAS. Highly dispersed Co-Ni bimetals on CaTiO3 were formed after reduction owing to the uniform distribution of nickel and cobalt ions in the perovskite phase. Through the reduction process, the bimetallic nanoparticles of Co-Ni with Co enriched in surface and Ni in core are produced. In addition, Coδ+ in the active pairs of Coδ+/Co0 were obtained via the interaction between Co and perovskite; and the chemical state of Co0 in the active pairs was tuned by the interaction between nickel and cobalt. The resulted catalyst showed excellent selectivity to higher alcohols with the total alcohols as high as 45.34 %. The higher alcohols reached 70.29 wt% at 270 °C, 3.0 MPa and a GHSV of 3900 mL g−1h−1 with H2/CO = 2/1.