Recently, the research group of Prof. Jie Zeng from Hefei National Laboratory for Physical Sciences at the Microscale & School of Chemistry and Materials Science, cooperated with Prof. Rui Si from Shanghai Synchrotron Radiation Facility, has made a great breakthrough in single-atom catalysis. The researchers demonstrated that metal-ligand cooperativity in Pt single atoms encapsulated in MIL-101 (Pt1@MIL) varied the reaction path and improved the selective hydrogenation of CO2 into methanol. This work has been published on the latest issue of Nature Communications with the title of “Optimizing Reaction Paths for Methanol Synthesis from CO2 Hydrogenation via Metal-ligand Cooperativity” (Nature Commun. 2019, 10, 1885).
Hydrogenation of CO2 into fuels and useful chemicals serves as an important process which helps to alleviate the dearth of fossil fuels. As diversified reaction paths co-exist over practical catalysts towards CO2 hydrogenation, it is highly desiderated to precisely control the reaction path for developing efficient catalysts.
The researchers revealed the metal-ligand cooperativity in Pt single atoms encapsulated in MIL-101 (Pt1@MIL) varied the reaction path and improved the selective hydrogenation of CO2 into methanol. In Pt1@MIL, every Pt single atom and its coordinated O atoms composed an active center. During CO2 hydrogenation, the selectivity for methanol reached 90.3% over Pt1@MIL. The cooperativity between Pt single atoms and their coordinated O atoms in Pt1@MIL enabled the dissociation of H2 to form O-H groups. The hydroxy H atoms added into CO2 to produce HCOO* as the intermediates. The unique reaction path over Pt1@MIL not only lowered the activation energy for the enhanced catalytic activity, but also contributed to the high selectivity for methanol.
This work reveals that upgrading the catalysts from nanocrystals to single atoms not only enhances the atomic utilization efficiency, but also alters the catalytic mechanisms such as the adsorption of reactants or intermediates on catalysts and the reaction path. This strategy offers a powerful means to improve the catalytic performance for CO2 hydrogenation, and extends our understanding of single-atom catalysis.
This work was supported by the CAS, MOST, NSFC, and National Synchrotron Radiation Laboratory.
Figure. Reaction path of CO2 hydrogenation over Pt1@MIL.