Investigation of heat treatment medium for C2+ alcohols synthesis from syngas over binary CuZn catalyst

The catalytic conversion of synthesis gas (CO + H 2 ) to C 2+ alcohols on Cu-based catalyst is a structure-sensitive process. A comprehensive understand of governing factors is crucial for rational design efficient catalysts for industrial applications. In this study, we systematically synthesize binary CuZn catalysts through medium-controlled thermal treatment process via complete liquid phase (CLP) technology. The catalyst treated in liquid paraffin shows considerable activity with CO conversion of 28.4 % and relative high selectivity of C 2+ alcohols (above 60 %), whereas PEG-400 treatment preferentially yielded methanol. A hybrid CZ-LP|CZ-PEG catalyst packed with two-stage exhibits potential for industrial application, with 26 % CO conversion and 62.2 % C 2+ alcohols selectivity while effectively suppressing the formation of CO 2 . Characterization analysis reveals that CO conversion shows a positive correlation with total acidity, whereas the selectivity of C 2+ alcohols is depended critically on the synergy between surface Cu + content and larger-sized CuZn particle. The presence of Cu + sites provides a higher possibility for CO∗/CHO∗ intermediates insertion, whereas larger CuZn particles favors to break the bridge-adsorptive CO to form CH x ∗ intermediates. Additionally, we propose a possible reaction pathway for C 2+ alcohols synthesis, highlighting the dual-sites cooperation mechanism. • Heat treatment medium affects the total acidity and surface Cu + content as well as the CuZn particle sizes. • CO conversion shows an increasing trend with the increase of total acidity. • The selectivity of C 2+ alcohols is depended on the synergy between surface Cu + and larger CuZn particle sizes. • A possible reaction pathway for C 2+ alcohols synthesis from syngas on binary CuZn catalyst is proposed.