<p>Upgrading light alkanes to value-added olefins is a long-standing challenge, owing to the high stability of C–H bonds and the tendency for overoxidation at elevated temperatures. Here, we introduce a light-driven strategy for ethane dehydrogenation using Cu-doped TiO<sub>2</sub>, in which atomically dispersed Cu coordinated to bridging oxygen (O<sub>br–Cu</sub>) creates well-defined [Cu–O] ensembles that orchestrate site-specific, stepwise C–H activation. Photogenerated holes localize at O<sub>br–Cu</sub> sites to initiate the first C–H cleavage, while adjacent Cu centers mediate β–H elimination and H<sub>2</sub> evolution. In contrast, minor β–H activation at O<sub>br–Ti</sub> sites generates *H species that cannot desorb due to a prohibitive coupling barrier with *H on O<sub>br–Cu</sub>, leading to Cu reduction and progressive deactivation. Co-feeding CO<sub>2</sub> restores the active Cu coordination environment and suppresses this deactivation process without perturbing the primary reaction pathway. This cooperative design achieves a C<sub>2</sub>H<sub>4</sub> production rate of 21.1 mmol g<sup>−1</sup> h<sup>−1</sup> with nearly stoichiometric H<sub>2</sub> evolution and an apparent&#xa0;quantum efficiency of 6.1% under 365 nm irradiation. These findings establish a site-defined, hydrogen-conserving route for photocatalytic alkane upgrading, offering a general blueprint for selective C–H bond transformations with long-term stability.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Site-defined Cu-O ensembles enable hydrogen-conserving light-driven ethane upgrading

  • Qingqing Zhang,
  • Cong Liu,
  • Chang Xu,
  • Dingnan Huang,
  • Cheng Xie,
  • Zhandong Wang,
  • Xiao-Ming Cao,
  • Jinlong Zhang,
  • Juying Lei,
  • Ziwei Ye,
  • Lingzhi Wang

摘要

Upgrading light alkanes to value-added olefins is a long-standing challenge, owing to the high stability of C–H bonds and the tendency for overoxidation at elevated temperatures. Here, we introduce a light-driven strategy for ethane dehydrogenation using Cu-doped TiO2, in which atomically dispersed Cu coordinated to bridging oxygen (Obr–Cu) creates well-defined [Cu–O] ensembles that orchestrate site-specific, stepwise C–H activation. Photogenerated holes localize at Obr–Cu sites to initiate the first C–H cleavage, while adjacent Cu centers mediate β–H elimination and H2 evolution. In contrast, minor β–H activation at Obr–Ti sites generates *H species that cannot desorb due to a prohibitive coupling barrier with *H on Obr–Cu, leading to Cu reduction and progressive deactivation. Co-feeding CO2 restores the active Cu coordination environment and suppresses this deactivation process without perturbing the primary reaction pathway. This cooperative design achieves a C2H4 production rate of 21.1 mmol g−1 h−1 with nearly stoichiometric H2 evolution and an apparent quantum efficiency of 6.1% under 365 nm irradiation. These findings establish a site-defined, hydrogen-conserving route for photocatalytic alkane upgrading, offering a general blueprint for selective C–H bond transformations with long-term stability.