【Frontiers in HaiChuan Chemical Technology】New strategy at Dalian Institute of Chemical Physics enables efficient synthesis of methanol from carbon dioxide via hydrogenation

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Recently, the team led by researchers Sun Jian and Yu Jiafeng from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, made new progress in the research on the conversion of carbon dioxide into methanol through hydrogenation. They proposed a new design strategy for the \"spatial decoupling\" of catalytic active sites, which enables the transformation from a redox pathway that is thermodynamically favorable to a formate pathway that is thermodynamically unfavorable; this approach suppresses the formation of the byproduct carbon monoxide. Even when the reaction temperature is increased, high methanol selectivity can still be maintained, offering a new approach to overcoming the dilemma in this field of balancing activity and selectivity. The relevant results were published in Chemistry. Methanol is an important chemical raw material and a potential carbon-neutral fuel, and its efficient synthesis is of great significance for achieving the recycling of carbon resources. The hydrogenation of carbon dioxide to methanol is a reaction that proceeds well at low temperatures; however, carbon dioxide is difficult to activate at low temperatures, resulting in low catalyst activity ； Although high temperatures are beneficial for increasing the conversion rate, they tend to promote the reverse water-gas shift side reaction, thereby reducing methanol selectivity. The “see-saw” effect between activity and selectivity has long constrained the improvement of methanol synthesis yields. The team utilized the strong interaction between metal and carrier to drive the formation of a coating structure that enabled the \"spatial decoupling\" of the active sites, separating the carbon dioxide activation sites from the hydrogen dissociation sites spatially. This allowed carbon dioxide to be adsorbed and activated preferentially on zirconia, enabling the synthesis of methanol via the \"formate\" pathway. Unlike the activation mechanism of carbon dioxide at copper sites, this design makes clever use of the activation mechanism at zirconia sites, which involves hydrogenation first followed by the breaking of the C=O bond, thereby suppressing the formation of the by-product carbon monoxide while retaining the high efficiency of copper sites in hydrogen dissociation. Under reaction conditions of 300 degrees Celsius and 3 MPa, the methanol selectivity of this copper-zinc-zirconium catalyst is 92%, and its space-time yield of methanol is three times that of existing commercial copper-zinc-aluminum catalysts. By reshaping the surface structure of the catalyst, this study altered the adsorption and dissociation mechanisms of the reactants as well as the reaction pathways, breaking the trade-off constraint between activity and selectivity and providing new approaches for the precise design of multifunctional catalysts.