Cu/ZnO/AlOOH catalyst for methanol synthesis through CO2 hydrogenation

Catalytic conversion of CO2 to methanol is gaining attention as a promising route to using carbon dioxide as a new carbon feedstock. AlOOH supported copper-based methanol synthesis catalyst was investigated for direct hydrogenation of CO2 to methanol. The bare AlOOH catalyst support was found to have increased adsorption capacity of CO2 compared to conventional Al2O3 support by CO2 temperature-programmed desorption (TPD) and FT-IR analysis. The catalytic activity measurement was carried out in a fixed bed reactor at 523 K, 30 atm and GHSV 6,000 hr(-1) with the feed gas of CO2/H-2 ratio of 1/3. The surface basicity of the AlOOH supported Cu-based catalysts increased linearly according to the amount of AlOOH. The optimum catalyst composition was found to be Cu : Zn : Al=40 : 30 : 30 at%. A decrease of methanol productivity was observed by further increasing the amount of AlOOH due to the limitation of hydrogenation rate on Cu sites. The AlOOH supported catalyst with optimum catalyst compositions was slightly more active than the conventional Al2O3 supported Cu-based catalyst.