Reversible Surface Segregation of Pt in a Pt3Au/C Catalyst and Its Effect on the Oxygen Reduction Reaction

2013 ◽  
Vol 117 (18) ◽  
pp. 9164-9170 ◽  
Author(s):  
Kug-Seung Lee ◽  
Hee-Young Park ◽  
Hyung Chul Ham ◽  
Sung Jong Yoo ◽  
Hyoung Juhn Kim ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Surface Segregation ◽  
Reduction Reaction

Mechanism for the enhanced oxygen reduction reaction of La0.6Sr0.4Co0.2Fe0.8O3−δ by strontium carbonate

2017 ◽  
Vol 19 (1) ◽  
pp. 503-509 ◽  
Author(s):  
Mei Li ◽  
Zhongti Sun ◽  
Wenqiang Yang ◽  
Tao Hong ◽  
Zhesheng Zhu ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Surface Segregation ◽  
Reduction Reaction ◽  
Strontium Carbonate

We demonstrate that SrCO3 can improve ORR on LSCF, solving the problem of contradicting effects of Sr surface segregation on LSCF.

Promotion of Oxygen Reduction Reaction Durability of Carbon-Supported PtAu Catalysts by Surface Segregation and TiO2 Addition

2014 ◽  
Vol 6 (3) ◽  
pp. 1589-1594 ◽  
Author(s):  
Chen-Wei Liu ◽  
Hong-Shuo Chen ◽  
Chien-Ming Lai ◽  
Jiunn-Nan Lin ◽  
Li-Duan Tsai ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Surface Segregation ◽  
Reduction Reaction ◽  
Tio2 Addition

N and S Co-doped Ordered Mesoporous Carbon: An Efficient Electrocatalyst for Oxygen Reduction Reaction in Microbial Fuel Cells

2020 ◽  
Vol 16 (4) ◽  
pp. 625-638
Author(s):  
Leila Samiee ◽  
Sedigheh Sadegh Hassani
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Microbial Fuel Cells ◽  
Carbon Materials ◽  
Reduction Reaction ◽  
Carbon Substrate ◽  
Promising Candidate ◽  
X Ray ◽  
Carbon Framework ◽  
Co Doped

Background: Porous carbon materials are promising candidate supports for various applications. In a number of these applications, doping of the carbon framework with heteroatoms provides a facile route to readily tune the carbon properties. The oxygen reduction reaction (ORR), where the reaction can be catalyzed without precious metals is one of the common applications for the heteroatom-doped carbons. Therefore, heteroatom doped catalysts might have a promising potential as a cathode in Microbial fuel cells (MFCs). MFCs have a good potential to produce electricity from biological oxidization of wastes at the anode and chemical reduction at the cathode. To the best of our knowledge, no studies have been yet reported on utilizing Sulfur trioxide pyridine (STP) and CMK-3 for the preparation of (N and S) doped ordered porous carbon materials. The presence of highly ordered mesostructured and the synergistic effect of N and S atoms with specific structures enhance the oxygen adsorption due to improving the electrocatalytic activity. So the optimal catalyst, with significant stability and excellent tolerance of methanol crossover can be a promising candidate for even other storage and conversion devices. Methods: The physico-chemical properties of the prepared samples were determined by Small Angle X-ray Diffraction (SAXRD), N2 sorption-desorption, Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FESEM) and X-ray Photoelectron Spectroscopy (XPS). The prepared samples were further applied for oxygen reduction reaction (ORR) and the optimal cathode was tested with the Microbial Fuel Cell (MFC) system. Furthermore, according to structural analysis, The HRTEM, and SAXRD results confirmed the formation of well-ordered hexagonal (p6mm) arrays of mesopores in the direction of (100). The EDS and XPS approved that N and S were successfully doped into the CMK-3 carbon framework. Results: Among all the studied CMK-3 based catalysts, the catalyst prepared by STP precursor and pyrolysis at 900°C exhibited the highest ORR activity with the onset potential of 1.02 V vs. RHE and 4 electron transfer number per oxygen molecule in 0.1 M KOH. The high catalyst durability and fuel-crossover tolerance led to stable performance of the optimal cathode after 5000 s operation, while the Pt/C cathode-based was considerably degraded. Finally, the MFC system with the optimal cathode displayed 43.9 mW·m-2 peak power density showing even reasonable performance in comparison to a Pt/C 20 wt.%.cathode. Conclusions: The results revealed that the synergistic effect of nitrogen and sulfur co-doped on the carbon substrate structure leads to improvement in catalytic activity. Also, it was clearly observed that the porous structure and order level of the carbon substrate could considerably change the ORR performance.

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