Synthesis and Catalytic Performance of Transition Metal Catalysts

Prof. Li Yadong’s group (Tsinghua University) prepared cobalt nanocrystals stabilized by nitrogen-doped graphitized carbon (Co NCs/NC) instead of Pt, Ir noble catalysts. The obtained Co NC/N-C catalyst demonstrated excellent catalytic performance toward both oxidative dehydrogenation of N-heterocycles and its reverse hydrogenation process under extremely mild conditions. Taking advantage of merits of NEXAFS (BL12a, HLS) for electronic and chemistry characterizations, the researchers revealed a Co–N coordination effect responsible for promoting the reaction. This strategy confers tremendous potential on the Co NCs/N-C for substituting noble-metal-based catalysts and soluble catalysts for homogeneous reactions [Chemical Science 10(20):5345-5352(2019)].

Left: Scheme of Co NCs/N-C obtained by the pyrolysis of ZIF-67. 

Right: (a) NEXAFS spectra of Co NCs/N-C, (b) XANES spectra (the blue area highlights the near-edge absorption energy) and (c) Fourier transform (FT) spectra of ZIF-67, Co NCs/N-C, catalysts treated in 500 ^oC H₂ and 300 ^oC air, and Co–BTC; (d) the N K-edge and (e) C Kedge of Co NCs/N-C; (f) the diagram of Co NCs encapsulated in N-doped carbon.