Electrochimica Acta, Vol.299, 610-617, 2019
Efficient and stable nanoporous functional composited electrocatalyst derived from Zn/Co-bimetallic zeolitic imidazolate frameworks for oxygen reduction reaction in alkaline media
A facile synthesis approach for metal-organic frameworks (MOFs) materials was studied for developing electrocatalysts with high electrochemical catalytic activity and stability. The prepared composite material contains two essential components: a predesigned bimetallic hybrid Zn/Co zeolitic imidazole frameworks (BMZIFs) and N-doped graphitic carbon (NGC) with various contents of carbon nanotubes (CNTs). Among which, NGC@CNTs-40 (100 mg NGC with 40mg CNTs) exhibits the best oxygen reduction reaction (ORR) performance in alkaline media. In addition, NGC@CNTs-40 shows high surface area of 353.9 m(2) g(-1), coexisting micro/mesoporous N-doped carbon, low I-D/I-G ratio and abundant N atomic species. Remarkably, NGC@CNTs-40 exhibited a limiting current density of 5.66mA cm(-2) and a half-wave potential of 0.81 V, which is comparable with commercial Pt/C (5.22 mA cm(-2) and 0.81 V) and most reported non-precious metal catalysts. Moreover, NGC@CNTs-40 exhibits better stability than Pt/C. The transferred electron number of NGC@CNTs-40 is 3.92, close to the ideal value of 4.0. The doping of CNTs into MOFs and the synergetic effect of Zn/Co-BMZIFs can enhance the conductivity of conventional MOFs and the blocked transfer of active substances in MOFs crystals, shedding new light on future applications. (C) 2019 Elsevier Ltd. All rights reserved.
Keywords:Zn/Co zeolitic imidazole frameworks;Synergetic effect;Carbon nanotubes;Oxygen reduction reaction