Recently, Prof. Deng Weiqiao’s team from the Institute of Molecular Science and Engineering of Qingdao Institute of Interdisciplinary Sciences made new progress in photo-driven CO₂ conversion. They have designed and synthesized a class of poly (ionic liquid) s (PILs) catalysts containing electron donor-acceptor (D-A) structure. Photo-driven CO₂ cycloaddition was achieved for the first time in the absence of metal species, co-catalysts and solvents. Relevant results are published as “Poly (ionic liquid) s for Photo-Driven CO2 Cycloaddition: Electron Donor-Acceptor Segments Matter " in the internationally renowned journal Advanced Science (TOP, IF=17.521). Master student Fang Xu and postdoctoral student Yang Li are the co-first authors. Professor Deng Weiqiao and Associate researcher Liu Chengcheng are the co-corresponding authors. Shandong University is the first corresponding organization.

Figure 1. The structure design of PILs with electron donor-acceptor segments

CO₂ cycloaddition reaction with epoxides to prepare cyclic carbonate is an important way of CO₂ conversion and utilization. The atomic utilization rate of this reaction is 100%. In most cases, the reaction can only be carried out efficiently under the condition of high temperature and high pressure with a homogeneous co-catalyst, facing the problems of high energy consumption and difficult separation of products. In this work, Deng’s group proposed to use solar energy as an energy source to promote the cycloaddition reaction of CO₂. They designed and synthesized a series of PILs catalysts containing electron donor-acceptors in the structure. The photo-driven reaction can be carried out efficiently without metal species, co-catalysts or solvents. For the same catalyst, the conversion rate of the photo-driven CO₂ cycloaddition reaction is nearly 5 times that of the thermal-driven reaction. Mechanism studies have shown that the presence of D-A structures in PILs can greatly promote the separation efficiency and transfer rate of the photogenerated carriers within the catalyst molecules, transfer the photogenerated electrons to epoxides efficiently and promote their ring-opening, thus accelerating the CO₂ cycloaddition reaction.

Figure 2. Proposed mechanism of photo-driven CO₂ cycloaddition reaction by D-A PILs

This work gained financial support from the Program of Young Scholars Future Program of Shandong University, the Natural Science Foundation of Shandong Province, the National Natural Science Foundation of China and the National Key Research and Development Program of China.

Link to the article：http://doi.org/10.1002/advs.202206687