scholarly journals Fe–N-Doped Mesoporous Carbon with Dual Active Sites Loaded on Reduced Graphene Oxides for Efficient Oxygen Reduction Catalysts

2018 ◽  
Vol 10 (3) ◽  
pp. 2423-2429 ◽  
Author(s):  
Chao Zhang ◽  
Jun Liu ◽  
Yixing Ye ◽  
Zabeada Aslam ◽  
Rik Brydson ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Mesoporous Carbon ◽  
Active Sites ◽  
Graphene Oxides ◽  
Reduced Graphene ◽  
Oxygen Reduction Catalysts ◽  
Reduced Graphene Oxides ◽  
Reduction Catalysts

scholarly journals Small Reduced Graphene Oxides for Highly Efficient Oxygen Reduction Catalysts

2021 ◽  
Vol 22 (22) ◽  
pp. 12300
Author(s):  
Su-Jeong Bak ◽  
Sun-I Kim ◽  
Su-yeong Lim ◽  
Taehyo Kim ◽  
Se-Hun Kwon ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Pt Nanoparticles ◽  
Graphene Oxides ◽  
Highly Efficient ◽  
Surface Areas ◽  
Reduced Graphene ◽  
High Metal ◽  
Oxygen Reduction Catalysts ◽  
Reduced Graphene Oxides ◽  
Reduction Catalysts

We demonstrated highly efficient oxygen reduction catalysts composed of uniform Pt nanoparticles on small, reduced graphene oxides (srGO). The reduced graphene oxide (rGO) size was controlled by applying ultrasonication, and the resultant srGO enabled the morphological control of the Pt nanoparticles. The prepared catalysts provided efficient surface reactions and exhibited large surface areas and high metal dispersions. The resulting Pt/srGO samples exhibited excellent oxygen reduction performance and high stability over 1000 cycles of accelerated durability tests, especially the sample treated with 2 h of sonication. Detailed investigations of the structural and electrochemical properties of the resulting catalysts suggested that both the chemical functionality and electrical conductivity of these samples greatly influence their enhanced oxygen reduction efficiency.

scholarly journals Mechanisms of Two-Electron and Four-Electron Electrochemical Oxygen Reduction Reactions at Nitrogen-Doped Reduced Graphene Oxide

2019 ◽  
Author(s):  
Hyo Won Kim ◽  
Vanessa Jane Bukas ◽  
Hun Park ◽  
Sojung Park ◽  
Kyle M. Diederichsen ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Isotope Effects ◽  
Underlying Mechanism ◽  
Reduction Reaction ◽  
Graphene Oxides ◽  
Nitrogen Doped ◽  
General Chemical ◽  
Reduced Graphene

Doped carbon-based systems have been extensively studied over the past decade as active electrocatalysts for both the two-electron (2e-) and four-electron (4e-) oxygen reduction reaction (ORR). However, the mechanisms for ORR are generally poorly understood. Here we report an extensive experimental and first-principles theoretical study of the ORR at nitrogen-doped reduced graphene oxides (NrGO). We synthesize three distinct NrGO catalysts and investigate their chemical and structural properties in detail via X-ray photoelectron spectroscopy, infrared and Raman spectroscopy, high-resolution transmission electron microscopy and thin-film electrical conductivity. ORR experiments include the pH dependences of 2e- versus 4e- ORR selectivity, ORR onset potentials, Tafel slopes and H/D kinetic isotope effects. These experiments show very different ORR behavior for the three catalysts, both in terms of selectivity and the underlying mechanism which proceeds either via coupled proton-electron transfers (CPETs) or non-CPETs. Reasonable structural models developed from DFT rationalize this behavior. The key determinant between CPET vs. non-CPET mechanisms is the electron density at the Fermi level under operating ORR conditions. Regardless of the reaction mechanism or electrolyte pH, however, we identify the ORR active sites as sp2 carbons that are located next to oxide regions. This assignment highlights the importance of oxygen functional groups, while details of (modest) N-doping may still affect the overall catalytic activity, and likely also the selectivity, by modifying the general chemical environment around the active site.

Identification of active sites in nitrogen and sulfur co-doped carbon-based oxygen reduction catalysts

Carbon ◽  
2019 ◽  
Vol 147 ◽  
pp. 303-311 ◽  
Author(s):  
Jin-Cheng Li ◽  
Xueping Qin ◽  
Peng-Xiang Hou ◽  
Min Cheng ◽  
Chao Shi ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Active Sites ◽  
Oxygen Reduction Catalysts ◽  
Reduction Catalysts ◽  
Co Doped ◽  
Carbon Based

Is reduced graphene oxide favorable for nonprecious metal oxygen-reduction catalysts?

Carbon ◽  
2016 ◽  
Vol 102 ◽  
pp. 346-356 ◽  
Author(s):  
Wei Gao ◽  
Dana Havas ◽  
Shiva Gupta ◽  
Qin Pan ◽  
Nanfei He ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Oxygen Reduction ◽  
Reduced Graphene Oxide ◽  
Reduced Graphene ◽  
Oxygen Reduction Catalysts ◽  
Reduction Catalysts ◽  
Nonprecious Metal

Recent progress in active sites for non-noble metal carbon-based oxygen reduction catalysts

2017 ◽  
Vol 47 (5) ◽  
pp. 554-564
Author(s):  
Wei Xing ◽  
Junjie Ge ◽  
Ergui Luo ◽  
Meiling Xiao ◽  
Changpeng Liu ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Noble Metal ◽  
Active Sites ◽  
Recent Progress ◽  
Oxygen Reduction Catalysts ◽  
Reduction Catalysts ◽  
Carbon Based

Efficient oxygen reduction catalysts formed of cobalt phosphide nanoparticle decorated heteroatom-doped mesoporous carbon nanotubes

2015 ◽  
Vol 51 (37) ◽  
pp. 7891-7894 ◽  
Author(s):  
Kuiyong Chen ◽  
Xiaobin Huang ◽  
Chaoying Wan ◽  
Hong Liu
Keyword(s):  
Carbon Nanotubes ◽  
Oxygen Reduction ◽  
Mesoporous Carbon ◽  
Carbon Nanostructures ◽  
Catalytic Performance ◽  
Electronic Interaction ◽  
Cobalt Phosphide ◽  
Carbon Structures ◽  
Oxygen Reduction Catalysts ◽  
Reduction Catalysts

Co2P nanoparticles could strongly promote the ORR catalytic performance of the heteroatom-doped carbon nanostructures via the electronic interaction between the embedded Co2P nanoparticles and the heteroatom-doped carbon structures.

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