Su Kaiyi, Gao Tengshijie, Tung Chen-Ho, Wu Li-Zhu
Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Angew Chem Int Ed Engl. 2024 Aug 26;63(35):e202407464. doi: 10.1002/anie.202407464. Epub 2024 Jul 29.
Plastic pollution is worsening the living conditions on Earth, primarily due to the toxicity and stability of non-biodegradable plastics (NBPs). Photocatalytic cracking of NBPs is emerging as a promising way to cleave inert C-C bonds and abstract the carbon atoms from these wastes into valuable chemicals and fuels. However, controlling these processes is a huge challenge, ascribed to the complicated reactions of various NBPs. Herein, we summarize recent advances in the CO and carbon-radical-mediated photocatalytic cracking of NBPs, with an emphasis on the pivotal intermediates. The CO-mediated cracking proceeded with indiscriminate C-H/C-C bond cleavage of NBPs and tandem photoreduction of CO, while carbon-radical-mediated cracking was realized by the prior activation of C-H bonds for selective C-C bond cleavage of NBPs. Catalytic generation and conversion of different intermediates greatly depend on the kinds of active species and the structure of photocatalysts under irradiation. Meanwhile, the fate of a specific intermediate is compared with small molecule activation to reveal the key problems in the cracking of NBPs. Finally, the challenges and potential directions are discussed to improve the overall efficiency in the photocatalytic cracking of NBPs.
塑料污染正在恶化地球的生活环境，这主要归因于不可生物降解塑料（NBP）的毒性和稳定性。NBP的光催化裂解正成为一种有前景的方法，用于裂解惰性的碳-碳键，并将这些废物中的碳原子转化为有价值的化学品和燃料。然而，由于各种NBP的反应复杂，控制这些过程是一项巨大的挑战。在此，我们总结了NBP的CO和碳自由基介导的光催化裂解的最新进展，重点关注关键中间体。CO介导的裂解通过NBP的无差别碳-氢/碳-碳键裂解和CO的串联光还原进行，而碳自由基介导的裂解则通过碳-氢键的预先活化实现NBP的选择性碳-碳键裂解。不同中间体的催化生成和转化在很大程度上取决于辐照下活性物种的种类和光催化剂的结构。同时，将特定中间体的归宿与小分子活化进行比较，以揭示NBP裂解中的关键问题。最后，讨论了提高NBP光催化裂解整体效率的挑战和潜在方向。
