In situ anchoring of metal nanoparticles in the N-doped carbon framework derived from conjugated microporous polymers towards an efficient oxygen reduction reaction

2018 ◽  
Vol 8 (14) ◽  
pp. 3572-3579 ◽  
Author(s):  
Qiang Li ◽  
Qi Shao ◽  
Qiong Wu ◽  
Qian Duan ◽  
Yanhui Li ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Metal Nanoparticles ◽  
Oxygen Reduction ◽  
Reduction Reaction ◽  
Microporous Polymers ◽  
Carbon Framework ◽  
Orr Activity ◽  
Conjugated Microporous Polymers

A series of efficient catalysts derived from metallophthalocyanine based conjugated microporous polymers show superior ORR activity in Zn–air batteries.

Mixed phthalocyanine-porphyrin-based conjugated microporous polymers towards unveiling the activity origin of Fe–N4 catalysts for the oxygen reduction reaction

2018 ◽  
Vol 6 (45) ◽  
pp. 22851-22857 ◽  
Author(s):  
Wenbo Liu ◽  
Kang Wang ◽  
Chiming Wang ◽  
Wenping Liu ◽  
Houhe Pan ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Reduction Reaction ◽  
Microporous Polymers ◽  
Conjugated Microporous Polymers

Mixed phthalocyanine-porphyrin-based conjugated microporous polymers with Fe–N4 active sites were fabricated with the origin of their ORR catalytic activity clarified.

scholarly journals Unveiling the Degradation Nature of Pt/NbOx/C Catalysts for Oxygen Reduction Reaction via in situ X-ray Absorption Spectroscopy

2021 ◽  
Author(s):  
Ershuai Liu ◽  
Qingying Jia ◽  
Jun Yang ◽  
Kai Sun ◽  
Li Jiao ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Absorption Spectroscopy ◽  
Reduction Reaction ◽  
X Ray ◽  
Orr Activity ◽  
X Ray Absorption

Among various metal nanoparticles supported on metal oxide (MMO) catalysts, the Pt/NbOx/C system has promising oxygen reduction reaction (ORR) activity as cathode for proton exchange membrane fuel cells (PEMFCs). Herein, we study a series of Pt/NbOx/C catalysts with tunable structural and electronic properties via physical vapor deposition and unravel the nature of metal and metal oxide interaction (MMOI) by characterizing this system under reactive conditions. By conducting in situ X-ray absorption spectroscopy (XAS) experiments, we demonstrate the Pt preferably interacts with O but not Nb in the Pt/NbOx/C system and such Pt-O interaction benefits the ORR activity via electronic effect rather than strain effect. We also provide clear evidence for the formation of metallic Nb phase at the early stage of PEMFC operation and identify severe particle growth of Pt after long-term PEMFC operation. These findings deepen our understanding of the degradation mechanism of MMO catalysts during long-term PEMFC operation.

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.

Toward synergy of carbon and La2O3 in their hybrid as an efficient catalyst for the oxygen reduction reaction

RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 77786-77795 ◽  
Author(s):  
Nan Wang ◽  
Jingjun Liu ◽  
Weiwei Gu ◽  
Ye Song ◽  
Feng Wang
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Reduction Reaction ◽  
Efficient Catalyst ◽  
Covalent Bonds ◽  
Orr Activity

The interficial covalent bonds formed in La2O3/C hybrid are responsible for its enhanced ORR activity.

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