Recently, the research team of Wang Tao and Zhou Zhiyou from Xiamen University published a research paper titled "Electrosynthesis of C6 Chemicals by Propylene Oxidative Coupling on Au Surface" in the Journal of the American Chemical Society (JACS). This study demonstrates for the first time the electrooxidative C-C coupling pathway of propylene on Au surfaces, extending common C3 oxidation reactions to C6 product synthesis.
Light olefins are among the most important platform molecules in modern chemical industry, with propylene widely used in the production of polypropylene, propylene oxide, acrylonitrile, and acrylic acid. However, selectively upgrading these relatively inert unsubstituted olefins to higher-value fine chemicals remains challenging.
The research team confirmed two C6 products through GC-MS and NMR: 2,5-hexanedione and 3-hexene-2,5-dione. Under mild electrochemical conditions, the total Faradaic efficiency of C6 products reached up to 36%, indicating that the coupling reaction can compete with traditional C3 oxidation pathways.
In situ ATR-SEIRAS, pressure-dependent experiments, and kinetic analysis show that C-C bond formation is controlled by the balance of *Pr and *PrOH surface coverage. DFT calculations demonstrate that the *Pr + *PrOH asymmetric coupling barrier is lower than the *Pr + *Pr and *PrOH + *PrOH pathways.
Industry Significance: This research provides new reaction strategies and mechanistic insights for light olefin electro-upgrading and green manufacturing of fine chemicals, potentially promoting high-value utilization of propylene as a plastics raw material.
