A Ferrocene Metal–Organic Framework Solid for Fe-Loaded Carbon Matrices and Nanotubes: High-Yield Synthesis and Oxygen Reduction Electrocatalysis

• Published in: Inorganic chemistry 2021-11, Vol.60 (22), p.17315-17324
• Main Authors: Cheng, Shengxian, Ma, Tengrui, Xu, Xiaohui, Du, Peng, Hu, Jieying, Xin, Yinger, Ahn, Dohyun, He, Jun, Xu, Zhengtao
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.1c02696

Using a carbon-rich designer metal–organic framework (MOF), we open a high-yield synthetic strategy for iron–nitrogen-doped carbon (Fe–N–C) nanotube materials that emulate the electrocatalysis performance of commercial Pt/C. The Zr­(IV)-based MOF solid boasts multiple key functions: (1) a dense array of alkyne units over the backbone and the side arms, which are primed for extensive graphitization; (2) the open, branched structure helps maintain porosity for absorbing nitrogen dopants; and (3) ferrocene units on the side arms as atomically dispersed precursor catalyst for targeting micropores and for effective iron encapsulation in the carbonized product. As a result, upon pyrolysis, over 89% of the carbon component in the MOF scaffold is successfully converted into carbonized products, thereby contrasting the easily volatilized carbon of most MOFs. Moreover, over 97% of the iron ends up being encased as acid-resistant Fe/Fe3C nanoparticles in carbon nanotubes/carbon matrices.