Preparation of CoCuGaK/ZrO2–Al2O3 Catalysts for the Synthesis of Higher Alcohols by CO Hydrogenation

A series of highly dispersed, mesoporous ZrO2-Al2O3-supported CoCuGa catalysts were prepared by incipient wetness impregnation and their catalytic performance was investigated in the synthesis of higher alcohols from syngas. The physicochemical properties of the catalysts were characterised by thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and hydrogen temperature-programmed reduction (H-2-TPR). The mesoporous ZrO2-Al2O3 structure allowed alcohol products to diffuse easily in and out of its pores, preventing hotspot formation and avoiding further hydrogenation to hydrocarbons. An appropriate amount of Ga added to the CoCu catalyst improved metal dispersion and CO uptake, resulting in significant enhancement of catalytic performance. The CoCuGaK/ZrO2-Al2O3 catalyst showed the highest conversion of CO and the greatest selectivity for total alcohols and C2+ alcohols.