Atomically Dispersed Co and Cu on N-Doped Carbon for Reactions Involving C-H Activation

作者：Xie, Jiahan; Kammert, James D.; Kaylor, Nicholas; Zheng, Jonathan W.; Choi, Eunjin; Pham, Hien N.; Sang, Xiahan; Stavitski, Eli; Attenkofer, Klaus; Unocic, Raymond R.; Datye, Abhaya K.; Davis, Robert J.^*

来源：ACS Catalysis, 2018, 8(5): 3875-3884.

DOI：10.1021/acscatal.8b00141

• heterogeneous catalyst
• C-H activation
• alcohol oxidation
• propane dehydrogenation
• nonprecious metal
• N-doped carbon
• in situ XAS
• coordination environment

Atomically dispersed Co(II) cations coordinated to nitrogen in a carbon matrix (Co-N-C) catalyze oxidative dehydrogenation of benzyl alcohol in water with a specific activity approaching that of supported Pt nanoparticles. Whereas Cu(II) cations in N-doped carbon also catalyze the reaction, they are about an order of magnitude less active compared with Co(II) cations. Results from X-ray absorption spectroscopy suggest that oxygen is also bound to N-coordinated Co(II) sites but that it can be partially removed by H-2 treatments at 523-750 K The N-coordinated Co(II) sites remained cationic in H-2 up to 750 K, and these stable sites were demonstrated to be active for propane dehydrogenation. In situ characterization of Cu(II) in N-doped carbon revealed that reduction of the metal in H-2 started at about 473 K, indicating a much lower thermal stability of Cu(II) in H-2 relative to Co(II). The demonstrated high catalytic activity and thermal stability of Co-N-C in reducing environments suggests that this material may have broad utility in a variety of catalytic transformations.

• 出版日期2018-5