Duan Meilin, Hu Canyu, Li Hao, Chen Yihong, Chen Ruitian, Gong Wanbing, Lu Zhou, Zhang Ning, Long Ran, Song Li, Xiong Yujie
School of Chemistry and Materials Science, and National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China.
Institute of Energy, Hefei Comprehensive National Science Center, 350 Shushanhu Road, Hefei, Anhui 230031, China.
JACS Au. 2022 May 13;2(5):1160-1168. doi: 10.1021/jacsau.2c00146. eCollection 2022 May 23.
Photocatalysis under mild conditions is an intriguing avenue for organic chemical manufacturing to confront the serious fossil energy crisis. Herein, we report a direct light-driven alkene production through alcohol dehydration, using nonstoichiometric tungsten oxide of WO nanowires with abundant lattice defects as a photocatalyst. A representative ethylene (CH) production rate of 275.5 mmol g h is achieved from ethanol (CHOH) dehydration, together with excellent selectivity up to 99.9%. The universality of our approach is further demonstrated with other alcohol dehydration. Combining ultrafast transient absorption spectroscopy with in situ X-ray photoelectron spectroscopy, we underline that the inter- and intraband transitions synergistically contribute to such excellent activity. In particular, the intraband transition excites the electrons in defect bands into an energetically "hot" state, largely alleviating the charge recombination. As a result, the C-OH bond of chemisorbed CHOH molecules can be effectively dissociated to furnish the formation of C=C bonds. Our work offers a fresh insight into sustainable alkene production with renewable energy input under mild conditions.
在温和条件下进行光催化是有机化学制造领域应对严重化石能源危机的一条引人关注的途径。在此，我们报道了一种通过醇脱水直接光驱动生产烯烃的方法，使用具有大量晶格缺陷的非化学计量比氧化钨纳米线（WO）作为光催化剂。从乙醇（CH₃CH₂OH）脱水反应中实现了代表性的乙烯（C₂H₄）生成速率为275.5 mmol g⁻¹ h⁻¹，同时选择性高达99.9%。我们的方法在其他醇脱水反应中进一步证明了其通用性。结合超快瞬态吸收光谱和原位X射线光电子能谱，我们强调带间和带内跃迁协同作用促成了如此优异的活性。特别是，带内跃迁将缺陷带中的电子激发到能量上的“热”态，极大地减轻了电荷复合。结果，化学吸附的CH₃CH₂OH分子的C - OH键能够有效地解离以形成C = C键。我们的工作为在温和条件下利用可再生能源输入实现可持续烯烃生产提供了新的见解。
