CO2 Hydrogenation to Produce Methanol over Fe, Ga and Mo Modified ZnCu-MOF and ZnCuAl-LDH Composite Catalysts

Abstract

To effectively mitigate the global warming issue, it is crucial to develop advanced technologies that can significantly reduce carbon dioxide emissions. CO₂ hydrogenation for methanol synthesis is increasingly recognized as a promising chemical approach for the green-house gas utilization. In this study, we present a highly active, selective and stable Mo modified ZnCu-MOF and ZnCuAl-LDH composite catalysts, which achieves 18% CO₂ conversion and 70% methanol selectivity at 230 °C, 3.0 MPa at a space velocity of 3600 mL·g_cat⁻¹·h⁻¹. Furthermore, after 140 h of operation, the catalyst demonstrates superior durability. In-situ DRIFT results reveal that this CO₂ hydrogenation reaction over the ZnCu-MOF and ZnCuAl-LDH composite catalysts proceeds through key intermediate formate species, ultimately leading to the methanol formation. In contrast, the Mo-modified catalysts facilitate the CO insertion reaction (CO₂ → CO*, CO* + *CH_x → CH₃OH), thereby enhancing the methanol yield.

Graphical Abstract