Recently, the joint team of Prof. Wu Limin and Gu Xiaojun from the College of Chemistry and Chemical Engineering and the College of Energy Materials and Chemistry at IMU has made significant research progress. The relevant findings have been published in the prestigious international academic journal in the field of chemistry, Angew. Chem. Int. Ed. The paper is titled "Plasma-Driven Efficient Conversion of CO2 and H2O into Pure Syngas with Controllable Wide H2/CO Ratios over Metal-Organic Frameworks Featuring In Situ Evolved Ligand Defects" (paper link: https://doi.org/10.1002/anie.202406007). Doctoral student Han Yali from the College of Chemistry and Chemical Engineering is the first author of the paper, with Prof. Wu Limin, Gu Xiaojun, and Researcher Fellow Zhang Jiangwei serving as corresponding authors. Inner Mongolia University is the primary institution credited for the paper.

The production of syngas from CO2 and H2O under mild conditions is a promising alternative to coal-based chemical engineering technologies. However, the inertia of CO2 molecules, unfavorable dissociation pathways of H2O molecules and the lack of suitable catalysts make it difficult to achieve both high CO2 conversion rates and controllable H2/CO ratios in synthesis gas simultaneously in catalytic reactions. To address this issue, the study focused on enhancing the activation of CO2 molecules and H2O molecules within nanoscale spaces, as well as regulating the electronic properties of metal catalytic active centers. A hydrophilic porous metal-organic framework (MOF) catalyst was constructed, and its performance and reaction mechanisms for the plasma-assisted catalytic conversion of CO2 and H2O were systematically investigated (Figure 1).

X-ray absorption spectroscopy revealed that as the catalytic reaction time extended, the coordination number of Cu-O in the MOF catalyst decreased, leading to an increase in the number of unsaturated Cu sites. When the catalytic reaction time driven by Cu-BTC was extended from 0.25 minutes to 1.0 minute, the CO2 conversion rate sharply increased from 22.5% to 61.9%. By controlling the catalyst and reaction conditions, the H2/CO ratio in the synthesis gas product could be adjusted between 0.05:1 and 4.3:1 (Figure 2). Isotope tracing experiments with 13CO2 confirmed that the carbon in the produced CO originated from the raw material CO2. Theoretical simulation calculations showed that when the Cu-O coordination number in the Cu-BTC catalyst was 4, the energy barrier for CO2 reduction to CO was the lowest, the adsorption effect of H2O molecules was the strongest, and the free energy of *H adsorption was the lowest, thus favoring the adsorption and activation of CO2.

In summary, this research provides a green and sustainable solution for the efficient production of syngas and provides new ideas for designing and constructing porous catalysts with precise defect structures and how to efficiently activate catalytic substrate molecules. This research has received support by key projects from the Ministry of Science and Technology, the National Natural Science Foundation of China, and the Science and Technology Plan of Inner Mongolia Autonomous Region.