Metal‐Oxo Electronic Tuning via In Situ CO Decoration for Promoting Methane Conversion to Oxygenates over Single‐Atom Catalysts
Weibin Xu, Hanxuan Liu, Yue Hu, Zhen Wang, Zheng‐Qing Huang, Chuande Huang, Jian Lin, Chun‐Ran Chang, Aiqin Wang, Xiaodong Wang, Tao Zhang
Abstract
Abstract Direct methane conversion (DMC) to oxygenates at low temperature is of great value but remains challenging due to the high energy barrier for C−H bond activation. Here, we report that in situ decoration of Pd 1 ‐ZSM‐5 single atom catalyst (SAC) by CO molecules significantly promoted the DMC reaction, giving the highest turnover frequency of 207 h −1 ever reported at room temperature and ~100 % oxygenates selectivity with H 2 O 2 as oxidant. Combined characterizations and DFT calculations illustrate that the C‐atom of CO prefers to coordinate with Pd 1 , which donates electrons to the Pd 1 −O active center (L−Pd 1 −O, L=CO) generated by H 2 O 2 oxidation. The correspondingly improved electron density over Pd−O pair renders a favorable heterolytic dissociation of C−H bond with low energy barrier of 0.48 eV. Applying CO decoration strategy to M 1 ‐ZSM‐5 (M=Pd, Rh, Ru, Fe) enables improvement of oxygenates productivity by 3.2–11.3 times, highlighting the generalizability of this method in tuning metal‐oxo electronic structure of SACs for efficient DMC process.