scholarly journals Fabrication of Conjugated Porous Polymer Catalysts for Oxygen Reduction Reactions: A Bottom-Up Approach

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1224
Author(s):  
Sujoy Bandyopadhyay ◽  
Su Ryong Ha ◽  
M. Alam Khan ◽  
Cheongbeom Lee ◽  
Hong In Jeong ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Density Functional ◽  
Condensation Reaction ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Porous Polymer ◽  
Alkaline Media ◽  
Dimensional Structure ◽  
Electron Transfer Mechanism

The present study demonstrates the fabrication of a conjugated porous polymer (CPP-P2) through a Pd-catalyzed Suzuki–Miyaura poly-condensation reaction. 13C cross-polarization solid-state NMR and Fourier transform infrared (FTIR) spectroscopy were used to characterize CPP-P2. Pristine nitrogen-containing CPP was explored as a catalyst for the oxygen reduction reaction in 0.1 M KOH aqueous alkaline media. In the case of CPP-P2,the polymer oxygen reduction reaction occurs via a four-electron transfer mechanism. An understanding of the oxygen reduction at the molecular level and the role of molecular packing in the three-dimensional structure was proposed based on density functional theory (DFT) modeling.

scholarly journals Carbon nanotube-linked hollow carbon nanospheres doped with iron and nitrogen as single-atom catalysts for the oxygen reduction reaction in acidic solutions

2019 ◽  
Vol 7 (24) ◽  
pp. 14478-14482 ◽  
Author(s):  
Jin-Cheng Li ◽  
Min Cheng ◽  
Tao Li ◽  
Lu Ma ◽  
Xiaofan Ruan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Single Atom ◽  
Dimensional Structure ◽  
Carbon Nanospheres ◽  
Acidic Solutions ◽  
Hollow Carbon

A three-dimensional structure consisting of atomically dispersed Fe, N-doped hollow carbon nanospheres linked by carbon nanotubes was engineered as an electrocatalyst showing a high activity for oxygen reduction reaction.

Enhancing the oxygen reduction reaction with three-dimensional graphene hollow nanosphere supported single-atomic cobalt catalyst

2020 ◽  
Vol 7 (18) ◽  
pp. 3475-3481
Author(s):  
Ji-Sen Li ◽  
Meng-Jie Huang ◽  
Xiao-Nan Chen
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Cobalt Catalyst ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Alkaline Media ◽  
Hollow Nanosphere ◽  
Methanol Tolerance ◽  
Long Term Stability

Three-dimensional graphene hollow nanospheres supported single-atomic cobalt catalyst shows superior electrocatalytic activity, long-term stability, and excellent methanol tolerance for the oxygen reduction reaction in alkaline media.

scholarly journals Unveiling the high-activity origin of single-atom iron catalysts for oxygen reduction reaction

2018 ◽  
Vol 115 (26) ◽  
pp. 6626-6631 ◽  
Author(s):  
Liu Yang ◽  
Daojian Cheng ◽  
Haoxiang Xu ◽  
Xiaofei Zeng ◽  
Xin Wan ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Density Functional ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Alkaline Media ◽  
Single Atom ◽  
Iron Catalysts ◽  
Grand Challenge ◽  
Orr Activity

It is still a grand challenge to develop a highly efficient nonprecious-metal electrocatalyst to replace the Pt-based catalysts for oxygen reduction reaction (ORR). Here, we propose a surfactant-assisted method to synthesize single-atom iron catalysts (SA-Fe/NG). The half-wave potential of SA-Fe/NG is only 30 mV less than 20% Pt/C in acidic medium, while it is 30 mV superior to 20% Pt/C in alkaline medium. Moreover, SA-Fe/NG shows extremely high stability with only 12 mV and 15 mV negative shifts after 5,000 cycles in acidic and alkaline media, respectively. Impressively, the SA-Fe/NG-based acidic proton exchange membrane fuel cell (PEMFC) exhibits a high power density of 823 mW cm−2. Combining experimental results and density-functional theory (DFT) calculations, we further reveal that the origin of high-ORR activity of SA-Fe/NG is from the Fe-pyrrolic-N species, because such molecular incorporation is the key, leading to the active site increase in an order of magnitude which successfully clarifies the bottleneck puzzle of why a small amount of iron in the SA-Fe catalysts can exhibit extremely superior ORR activity.

scholarly journals Metal Organic Framework Derived MnO2-Carbon Nanotubes for Efficient Oxygen Reduction Reaction and Arsenic Removal from Contaminated Water

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1895
Author(s):  
Vadahanambi Sridhar ◽  
Inwon Lee ◽  
Kwang Hyo Jung ◽  
Hyun Park
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Arsenic Removal ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Nano Particles ◽  
Alkaline Media ◽  
Metal Organic

Even though manganese oxides are attractive materials for batteries, super-capacitors and electro-catalysts for oxygen reduction reactions, in most practical applications MnO2 needs to be hybridized with conductive carbon nano-structures to overcome its inherent poor electrical conductivity. In this manuscript we report microwave-assisted synthesis of MnO2 embedded carbon nanotubes (MnO2@CNT) from Mn-H3BTC (benzene-1,3,5-carboxylic acid) metal organic frameworks (MOF) precursors. Using graphene oxide as microwave susceptible surface, MnO2 nano-particles embedded in three dimensional reduced graphene oxide (rGO) -CNT frameworks (MnO2@CNT-rGO) were synthesized which when applied as electro-catalysts in oxygen reduction reaction (ORR) demonstrated comparable half-wave potential to commercial Pt/C, better stability, and excellent immunity to methanol crossover effect in alkaline media. When carbon fiber (CF) was used as substrate, three-dimensional MnO2@CNT-CF were obtained whose utility as effective adsorbents for arsenic removal from contaminated waters is demonstrated.

scholarly journals MnS-Nanoparticles-Decorated Three-Dimensional Graphene Hybrid as Highly Efficient Bifunctional Electrocatalyst for Hydrogen Evolution Reaction and Oxygen Reduction Reaction

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1141
Author(s):  
Khalil ur Rehman ◽  
Shaista Airam ◽  
Long Song ◽  
Jian Gao ◽  
Qiang Guo ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Manganese Sulfide ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Alkaline Media ◽  
Renewable Energy Resources ◽  
Bifunctional Electrocatalyst

The search for renewable energy resources has attracted considerable research interests in electrochemical reactions of hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) that are essential for fuel cells. Earth-abundant, eco-friendly and cost-effective transition metal compounds are emerging candidates as electrocatalysts in these reactions. Herein, we report the growth of manganese sulfide nanoparticles on three-dimensional graphene, through an easy, progressive successive ionic layer adsorption and reaction (SILAR) method, where manganese sulfide nanoparticles (MnS-NPs), diameter of 4–5 nm are homogeneously decorated on the 3D graphene matrix. The formed hybrid shows improved HER activity in 0.1 M KOH when compared to bulk MnS. Moreover, MnS-NPs@3DG is also active in catalyzing ORR, qualifying it as a new type of bifunctional electrocatalyst in alkaline media.

scholarly journals Integrated Three-Dimensional Carbon Nanopolyhedron/Metal Sulfides: An Efficient Electrocatalyst Toward Oxygen Reduction Reaction

2021 ◽  
Vol 9 ◽  
Author(s):  
Yi-Wen Yang ◽  
Bing-Ye Song
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Synergistic Effects ◽  
Three Dimensional ◽  
Carbon Matrix ◽  
Structural Features ◽  
Reduction Reaction ◽  
Alkaline Media ◽  
Metal Sulfides ◽  
High Porosity

Carbon-based materials hybridized with metal sulfides have gained growing attention as catalytic materials for oxygen reduction reaction (ORR) due to their synergistic effects in terms of richer structural features and higher electrochemical activities. Here, a series of Zn/Co/Fe-based metal-organic frameworks (MOFs) as the precursors, which can be adopted as efficient ORR catalysts, were synthesized through a sulfuration–calcination treatment. The effects of precursor composition, heteroatom doping, and pyrolysis temperature on the structure and electrochemical performance of the catalysts were discussed in detail. It is found that well-grown carbon nanotubes (CNTs) on the surface of graphitic carbon matrix are formed under the synergy effect of trimetallic-based species during pyrolysis. Benefiting from the three-dimensional unique structure with appropriate dopants and high porosity, the catalyst derived from the optimized Zn/Co/Fe-MOFs achieves a half-wave potential of 0.87 V in an alkaline medium for ORR, which is comparable with commercial electrocatalysts. In addition, an outstanding ORR durability of the proposed catalyst in alkaline media was also demonstrated. This work highlights the potential to rationally design and fabricate high-performance ORR catalysts for commercialization.

Ag–Cu Bimetallic Nanoparticles as Efficient Oxygen Reduction Reaction Electrocatalysts in Alkaline Media

2020 ◽  
Vol 20 (3) ◽  
pp. 1765-1772 ◽  
Author(s):  
Alkadevi Verma ◽  
Rajeev Kumar Gupta ◽  
Madhulata Shukla ◽  
Manisha Malviya ◽  
Indrajit Sinha
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Density Functional ◽  
Bimetallic Nanoparticles ◽  
Peak Position ◽  
Reduction Reaction ◽  
Alkaline Media ◽  
Reduction Peak ◽  
Functional Theory ◽  
Water Activation

The alkaline medium oxygen reduction reaction (ORR) activities of Ag–Cu bimetallic nanoparticles (BNPs), consisting of neighboring Ag and Cu domains, were studied and compared with those of pure Ag and Cu nanoparticles prepared by the same polyol route. Three variations of Ag–Cu BNPs viz. Ag–Cu (4:1), Ag–Cu (2:1), Ag–Cu (1:1) BNPs were considered. The electrocatalytic performances of these nanoparticles were investigated by using different techniques, such as cyclic voltammetry (CV) and linear sweep voltammograms (LSV). The Ag–Cu bimetallics demonstrated synergistic ORR electrocatalytic activity compared to pure Ag or Cu. Optimum values of these parameters were observed for Ag–Cu (4:1) BNPs. According to LSV, the reduction peak position is at lower applied potential and showed higher intensity for the Ag–Cu (4:1) as compared to Ag–Cu (2:1) and Ag–Cu (1:1) BNPs. Density Functional Theory (DFT) calculations show that charge transfer from Cu to Ag (in the bimetallic nanoparticles) results in their stronger oxygen interaction and water activation properties relative to that of pure Ag nanoparticles.

A three-dimensional Mn3O4 network supported on a nitrogenated graphene electrocatalyst for efficient oxygen reduction reaction in alkaline media

2014 ◽  
Vol 2 (35) ◽  
pp. 14493-14501 ◽  
Author(s):  
Santosh Kumar Bikkarolla ◽  
Fengjiao Yu ◽  
Wuzong Zhou ◽  
Paul Joseph ◽  
Peter Cumpson ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Reduced Graphene Oxide ◽  
Alkaline Medium ◽  
High Performance ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Alkaline Media ◽  
Reduced Graphene

A 3D hierarchical Mn3O4 nanoflake structure supported on nitrogenated reduced graphene oxide (NrGO), with excellent oxygen reduction in alkaline medium, was developed by electrodeposition. High performance is attributed to poor nanoflake crystallinity and strong nanoflake–NrGO coupling.

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