CO2 hydrogenation over copper-based hybrid catalysts for the synthesis of oxygenates

Hybrid catalysts consisting of Cu-based methanol synthesis catalyst and zeolite were investigated for CO2 hydrogenation by following the idea that thermodynamic limitation in methanol synthesis from CO2 hydrogenation could be overcome through in situ transformation of methanol to dimethylether(DME) to enhance the yield of oxygenates (methanol + DME). Cu/ZnO/ZrO2 and Cu/ZnO/Ga2O3 were chosen as methanol synthesis catalysts, and NaZSM-5, HZSM5, H-Ga-silicate and SAPO-34 as zeolites. The hybrid catalyst of Cu/ZnO/ZrO2 and H-Ga-silicate showed the highest yield of oxygenates. The modification of reducibility or oxygen coverage due to the interactions between methanol synthesis catalyst and zeolite was found to improve the catalytic performance in oxygenates synthesis.