Zhefu Li,Binling Chen,Xianfeng Wang,Jun Nie,Guiping Ma
In this work, a novel catalyst of oxygen reduction reaction (ORR) was designed and fabricated by electrospinning, photo-curing and carbonization, based on polymer poly(dimethylsilylene ethynylenephenyleneethynylene) (PMSEPE) and metal organic frameworks (MOFs)—Materiaux de l'Institute Lavosier-101(Fe) (MIL-101(Fe)). The optimal catalyst PMSEPE/MIL-101(Fe)-800, which was carbonized at 800 °C, presented a bamboo-like nanofiber structure with a high degree of graphitization, a high specific surface area (302.3 m 2 /g) and a high yield (64.17%). Fe 3 C particles were found to be encapsulated into the Fe-Si-N co-doped carbon nanofibers. In the electrochemical tests, PMSEPE/MIL-101(Fe)-800 showed an onset potential of 0.935 V ( vs . RHE) and a diffusion limit current of 6.01 mA/cm 2 ( vs . RHE) in 0.1 M KOH aqueous solution, of which performances are competitive to commercial 20 wt% Pt/C. PMSEPE/MIL-101(Fe)-800 also exhibited a higher methanol tolerance and duration stability. Further Zn-air battery test used by PMSEPE/MIL-101(Fe)-800 suggested its potential for the application of fuel cell.
Lithium-sulfur(Li-S) batteries have been puzzled by the “shuttle effect”. In the recent years, catalytic materials present a huge potential for solving this problem. However, the exploitation for catalytic activity was still challenging in Li-S batteries. In this article, we put forward a single atom catalyst (SAC) of FeN 4 coupled with Fe 3 C on the N-doped carbon (FeN 4 /Fe 3 C@NC) by one-step pyrolysis method. The FeN 4 and Fe 3 C synergistically catalyze the polysulfides conversion when the N-doped carbon provides the high conductive three-dimensional skeleton in Li-S batteries. As a result, the FeN 4 /Fe 3 C@NC shows a specific capacity of 1100 mA·h/g at 0.2 C(1 C=1675 mA/g). In addition, the FeN 4 /Fe 3 C@NC maintains 99.01% of the pristine specific capacity after 100 cycles at 0.5 C, indicating the improved electrochemical performance in Li-S batteries. This work sheds new lights on the design of engineering catalysts for developing high-performance Li-S batteries.
危险品化学品经营许可证（带存储）