Efficient methanol synthesis is considered a promising approach for carbon resource recycling. Hydrogenation of carbon dioxide (CO2) to methanol is thermodynamically favored at low temperatures, but the sluggish activation kinetics of CO2 under such conditions lead to low catalytic activity. Higher temperatures can enhance reaction rates but also promote the reverse water-gas shift side reaction, which reduces methanol selectivity. This "seesaw" effect between activity and selectivity has long limited improvements in methanol yield.
In a recent study published in Chem, a research team led by Prof. SUN Jian and Prof. YU Jiafeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) proposed a novel design strategy that spatially decouples active sites through a strong metal-support interaction (SMSI)-driven overlayer structure, enabling efficient methanol synthesis from CO2.
By reconstructing the catalyst surface structure and modifying the adsorption and dissociation modes of reactants as well as the reaction pathway, the researchers achieved a space-time yield of 1.2 g·gcat-1·h-1 under reaction conditions of 300 ℃ and 3 MPa, which is about three times higher than that of conventional commercial Cu/Zn/Al catalysts.
The researchers found that this strategy could direct CO2 to preferentially adsorb and activate on zirconia (ZrO2), guiding the reaction toward methanol synthesis via the formate pathway. Unlike the conventional activation mode on Cu sites, which involved breaking the C=O bond before hydrogenation, this strategy employed an alternative mechanism, allowing hydrogenation to occur first on ZrO2 sites, followed by C=O bond cleavage. This fundamental shift effectively suppresses the formation of CO by-product while retaining the high efficiency of Cu sites for H2 dissociation.
"Our study may provide a new pathway to addressing the long-standing trade-off between activity and selectivity in methanol synthesis from CO2," said Prof. SUN.
