A series of bimetallic Ni–Co catalysts supported on Mn–Al oxide with different Ni/Co molar ratios were synthesized using a sol–gel method and applied for CO hydrogenation to higher alcohols. The physical and chemical properties of the as-prepared catalysts were investigated by various characterization methods such as XRD, N₂ adsorption/desorption, H₂-TPR, TEM, XPS, CO-TPD, H₂-TPD, and CO-TPSR. The results indicated that a stronger interaction between Ni and Co ions led to the formation of a Ni–Co alloy in the reduced catalysts, and CO conversion and alcohol selectivity changed depending on the Ni/Co molar ratio that significantly influenced the properties of the catalysts. The appropriate Ni/Co molar ratio can improve the reducibility, increase the amount of non-dissociated CO on the catalyst surface for CO insertion, and enhance the catalytic performance for higher alcohol synthesis. In particular, a Ni/Co molar ratio of 5/3 was found to be the most suitable for the physical–chemical and catalytic properties of the bimetallic Ni–Co catalysts for CO hydrogenation to higher alcohols.

The figure presented the catalytic performances of composite supported V ₂ O ₅ –TiO ₂ –SiO ₂ catalyst prepared by improved sol–gel method. V ₂ O ₅ –TiO ₂ –SiO ₂ catalyst showed efficient activity of 51% methanol conversion and 99% DMM selectivity at 413 K.

Cu–Mg–Fe–M–O (M = Mn, Zr, and Ce) catalysts derived from layered double hydroxides (LDHs) precursors were prepared using a co-precipitation method and tested for higher alcohol synthesis (HAS) via carbon monoxide hydrogenation. The catalysts were subsequently characterized by N₂-physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and H₂ temperature-programed reduction (H₂-TPR). The results show that Mn, Zr, and Ce promoters mainly contribute to the formation of tetrahedrally coordinated copper species, which favor the enhancement of the total alcohol selectivity. The addition of Mn facilitates the interaction between Cu and Fe, which causes the total alcohol selectivity and C₂₊ alcohol content in the total alcohols increased from 9.82% and 68.85% to 15.1% and 73.14%, respectively. However, the addition of Zr and Ce weakens the Cu–Fe interaction but increases the possibility of contact between Cu and Fe. As a consequence, the total alcohol selectivity is enhanced, while the C₂₊ alcohol content in the total alcohols is reduced upon Zr and Ce addition. Based on the characterization and catalytic results of the catalysts, a triple-active-site model is proposed to explain the different promoting effects of the three additives.

The peculiar structure of FeMn@C not only facilitates the formation of χ-Fe ₅ C ₂ , but it also promotes the product selectivity of light olefins.